Unbound Caching and NSD Local Authoritative Master Slave DNS Server – Part I

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Unbound: Caching DNS Resolver

When FreeBSD 10 removed Bind from the base, a certain level of uneasiness and relief was felt in the FreeBSD Community.  Always fond of Bind, it was time to move on to an alternate without all the complexity, security issues, licensing and feature bloat of Bind.  For these and other reasons, Unbound was chosen as a caching DNS server and NSD for an authoritative DNS Server for local zones.  Additionally, redundancy is required since this is a production environment which requires uninterruptible DNS resolution. Our environment will consist of two physical servers both configured as follows:

 

Operating Environment:

Server 1:

Hostname: bsd220.loga.us

IP Address: 192.168.0.220/24

Unbound Caching DNS Server: 192.168.0.220@53

Master NSD DNS Server: 192.168.0.220@5053

 

Server 2:

Hostname: bsd222.loga.us

IP Address: 192.168.0.222/24

Unbound Caching DNS Server: 192.168.0.222@53

Slave NSD DNS Server: 192.168.0.222@5053

 

Before starting some important notes:

From the FreeBSD Handbook:

“Unbound is provided in the FreeBSD (10) base system. By default, it will provide DNS resolution to the local machine only. While the base system package can be configured to provide resolution services beyond the local machine, it is recommended that such requirements be addressed by installing Unbound from the FreeBSD Ports Collection.”

 

Additionally, if Unbound is installed from the Ports Collection, you will need to reconfigure your environmental variables in your shell in order for the search paths to first look at /usr/local/bin and /usr/local/sbin.  This is important so you will not inadvertently use the Unbound installed in the base system when using unbound-control (8).

And finally as a reminder, unbound by default is installed in a chroot directory structure.

 

Below is the set path statement in my .cshrc file

set path = (/usr/games /usr/local/sbin /usr/local/bin /sbin /bin /usr/sbin /usr/bin $HOME/bin)

Reboot in order for the new setting to take effect.

 

Unbound:

Let’s start by installing Unbound on each server:

# portsnap fetch update
# cd /usr/ports/dns/unbound
# make install clean

 

Next, create an unbound.conf from the sample file on each server:

# cd /usr/local/etc/unbound
# cp unbound.conf.sample unbound.conf

 

Before starting to configure unbound.conf, unbound needs a root.hints file which lists the primary DNS Servers.  Unbound comes with a listing of the root DNS Servers in its code, but this ensures the most up to date copy on each server.  A good practice is to update this file every six months.

wget ftp://FTP.INTERNIC.NET/domain/named.cache -O /usr/local/etc/unbound/root.hints

 

Additionally, Unbound requires an auto-trust-anchor-file.  It contains a key in order for DNSSEC to be validated.  To generate the root.key execute the following commands on each server:

# cd /usr/local/etc/unbound
# unbound-anchor -a "/usr/local/etc/unbound/root.key"

 

rc.conf:

Next, let’s setup unbound to startup automatically by adding the following line in our /etc/rc.conf on each server:

unbound_enable="YES"

 

resolv.conf:

Let’s not forget to change our /etc/resolv.conf file so any queries will be resolved by Unbound on each server:

search loga.us
nameserver 127.0.0.1

 

unbound-control:

Next step is to generate the keys needed for Unbound to be controlled by unbound-control (8). 

# cd /usr/local/etc/unbound
# unbound-control-setup

 

Log Files:

Finally, create a separate directory for the log files:

# cd /usr/local/etc/unbound
# mkdir log
# chown unbound log

 

unbound.conf:

Here’s the complete /usr/local/etc/unbound/unbound.conf file for Server 1:

Note:  Please refer to the uncommented statements and adjust to your environment.

 

 #
 # Server bsd220.loga.us 
 #
 # See unbound.conf(5) man page, version 1.4.22.
 #
 # this is a comment.

 # Use this to include other text into the file.
 # include: "otherfile.conf"

 # The server clause sets the main parameters. 

 server:

 # whitespace is not necessary, but looks cleaner.

 # verbosity number, 0 is least verbose. 1 is default.
   verbosity: 1

 # print statistics to the log (for every thread) every N seconds.
 # Set to "" or 0 to disable. Default is disabled.
 # statistics-interval: 0

 # enable cumulative statistics, without clearing them after printing.
 # statistics-cumulative: no

 # enable extended statistics (query types, answer codes, status)
 # printed from unbound-control. default off, because of speed.
 # extended-statistics: no

 # number of threads to create. 1 disables threading.
   num-threads: 1

 # specify the interfaces to answer queries from by ip-address.
 # The default is to listen to localhost (127.0.0.1 and ::1).
 # specify 0.0.0.0 and ::0 to bind to all available interfaces.
 # specify every interface[@port] on a new 'interface:' labelled line.
 # The listen interfaces are not changed on reload, only on restart.
 # interface: 192.0.2.153
 # interface: 192.0.2.154
 # interface: 192.0.2.154@5003
 # interface: 2001:DB8::5
   interface: 127.0.0.1
   interface: 192.168.0.220
 
 # enable this feature to copy the source address of queries to reply.
 # Socket options are not supported on all platforms. experimental. 
 # interface-automatic: no

 # port to answer queries from
   port: 53

 # specify the interfaces to send outgoing queries to authoritative
 # server from by ip-address. If none, the default (all) interface
 # is used. Specify every interface on a 'outgoing-interface:' line.
 # outgoing-interface: 192.0.2.153
 # outgoing-interface: 2001:DB8::5
 # outgoing-interface: 2001:DB8::6

 # number of ports to allocate per thread, determines the size of the
 # port range that can be open simultaneously. About double the
 # num-queries-per-thread, or, use as many as the OS will allow you.
 # outgoing-range: 4096

 # permit unbound to use this port number or port range for
 # making outgoing queries, using an outgoing interface.
 # outgoing-port-permit: 32768

 # deny unbound the use this of port number or port range for
 # making outgoing queries, using an outgoing interface.
 # Use this to make sure unbound does not grab a UDP port that some
 # other server on this computer needs. The default is to avoid
 # IANA-assigned port numbers.
 # If multiple outgoing-port-permit and outgoing-port-avoid options
 # are present, they are processed in order.
 # outgoing-port-avoid: "3200-3208"

 # number of outgoing simultaneous tcp buffers to hold per thread.
 # outgoing-num-tcp: 10

 # number of incoming simultaneous tcp buffers to hold per thread.
 # incoming-num-tcp: 10

 # buffer size for UDP port 53 incoming (SO_RCVBUF socket option).
 # 0 is system default. Use 4m to catch query spikes for busy servers.
   so-rcvbuf: 1m

 # buffer size for UDP port 53 outgoing (SO_SNDBUF socket option).
 # 0 is system default. Use 4m to handle spikes on very busy servers.
   so-sndbuf: 1m 
 
 # on Linux(3.9+) use SO_REUSEPORT to distribute queries over threads.
 # so-reuseport: no

 # EDNS reassembly buffer to advertise to UDP peers (the actual buffer
 # is set with msg-buffer-size). 1480 can solve fragmentation (timeouts).
 # edns-buffer-size: 4096

 # Maximum UDP response size (not applied to TCP response).
 # Suggested values are 512 to 4096. Default is 4096. 65536 disables it.
 # max-udp-size: 4096

 # buffer size for handling DNS data. No messages larger than this
 # size can be sent or received, by UDP or TCP. In bytes.
 # msg-buffer-size: 65552

 # the amount of memory to use for the message cache.
 # plain value in bytes or you can append k, m or G. default is "4Mb". 
   msg-cache-size: 128m

 # the number of slabs to use for the message cache.
 # the number of slabs must be a power of 2.
 # more slabs reduce lock contention, but fragment memory usage.
 # msg-cache-slabs: 4

 # the number of queries that a thread gets to service.
 # num-queries-per-thread: 1024

 # if very busy, 50% queries run to completion, 50% get timeout in msec
 # jostle-timeout: 200
 
 # msec to wait before close of port on timeout UDP. 0 disables.
 # delay-close: 0

 # the amount of memory to use for the RRset cache.
 # plain value in bytes or you can append k, m or G. default is "4Mb". 
   rrset-cache-size: 256m

 # the number of slabs to use for the RRset cache.
 # the number of slabs must be a power of 2.
 # more slabs reduce lock contention, but fragment memory usage.
 # rrset-cache-slabs: 4
 
 # the time to live (TTL) value lower bound, in seconds. Default 0.
 # If more than an hour could easily give trouble due to stale data.
 # cache-min-ttl: 0

 # the time to live (TTL) value cap for RRsets and messages in the
 # cache. Items are not cached for longer. In seconds.
 # cache-max-ttl: 86400

 # the time to live (TTL) value for cached roundtrip times, lameness and
 # EDNS version information for hosts. In seconds.
 # infra-host-ttl: 900

 # the number of slabs to use for the Infrastructure cache.
 # the number of slabs must be a power of 2.
 # more slabs reduce lock contention, but fragment memory usage.
 # infra-cache-slabs: 4 

 # the maximum number of hosts that are cached (roundtrip, EDNS, lame).
 # infra-cache-numhosts: 10000

 # Enable IPv4, "yes" or "no".
   do-ip4: yes

 # Enable IPv6, "yes" or "no".
 # do-ip6: yes

 # Enable UDP, "yes" or "no".
   do-udp: yes

 # Enable TCP, "yes" or "no".
   do-tcp: yes

 # upstream connections use TCP only (and no UDP), "yes" or "no"
 # useful for tunneling scenarios, default no.
 # tcp-upstream: no

 # Detach from the terminal, run in background, "yes" or "no".
 # do-daemonize: yes

 # control which clients are allowed to make (recursive) queries
 # to this server. Specify classless netblocks with /size and action.
 # By default everything is refused, except for localhost.
 # Choose deny (drop message), refuse (polite error reply),
 # allow (recursive ok), allow_snoop (recursive and nonrecursive ok)
 # deny_non_local (drop queries unless can be answered from local-data)
 # refuse_non_local (like deny_non_local but polite error reply).
 # access-control: 0.0.0.0/0 refuse
 # access-control: 127.0.0.0/8 allow
 # access-control: ::0/0 refuse
 # access-control: ::1 allow
 # access-control: ::ffff:127.0.0.1 allow
   access-control: 127.0.0.0/8 allow
   access-control: 192.168.0.0/24 allow

 # if given, a chroot(2) is done to the given directory.
 # i.e. you can chroot to the working directory, for example,
 # for extra security, but make sure all files are in that directory.
 #
 # If chroot is enabled, you should pass the configfile (from the
 # commandline) as a full path from the original root. After the
 # chroot has been performed the now defunct portion of the config 
 # file path is removed to be able to reread the config after a reload. 
 #
 # All other file paths (working dir, logfile, roothints, and
 # key files) can be specified in several ways:
 # o as an absolute path relative to the new root.
 # o as a relative path to the working directory.
 # o as an absolute path relative to the original root.
 # In the last case the path is adjusted to remove the unused portion.
 #
 # The pid file can be absolute and outside of the chroot, it is 
 # written just prior to performing the chroot and dropping permissions.
 #
 # Additionally, unbound may need to access /dev/random (for entropy).
 # How to do this is specific to your OS.
 #
 # If you give "" no chroot is performed. The path must not end in a /.
   chroot: "/usr/local/etc/unbound"

 # if given, user privileges are dropped (after binding port),
 # and the given username is assumed. Default is user "unbound".
 # If you give "" no privileges are dropped.
   username: "unbound"

 # the working directory. The relative files in this config are 
 # relative to this directory. If you give "" the working directory
 # is not changed.
   directory: "/usr/local/etc/unbound"

 # the log file, "" means log to stderr. 
 # Use of this option sets use-syslog to "no".
   logfile: "/usr/local/etc/unbound/log/unbound.log"

 # Log to syslog(3) if yes. The log facility LOG_DAEMON is used to 
 # log to, with identity "unbound". If yes, it overrides the logfile.
 # use-syslog: yes 

 # print UTC timestamp in ascii to logfile, default is epoch in seconds.
   log-time-ascii: yes 
 
 # print one line with time, IP, name, type, class for every query.
 # log-queries: no

 # the pid file. Can be an absolute path outside of chroot/work dir.
   pidfile: "/usr/local/etc/unbound/unbound.pid"

 # file to read root hints from.
 # get one from ftp://FTP.INTERNIC.NET/domain/named.cache
   root-hints: "/usr/local/etc/unbound/root.hints"

 # enable to not answer id.server and hostname.bind queries.
   hide-identity: yes 

 # enable to not answer version.server and version.bind queries.
   hide-version: yes 

 # the identity to report. Leave "" or default to return hostname.
 # identity: ""

 # the version to report. Leave "" or default to return package version.
 # version: ""

 # the target fetch policy.
 # series of integers describing the policy per dependency depth. 
 # The number of values in the list determines the maximum dependency 
 # depth the recursor will pursue before giving up. Each integer means:
 # -1 : fetch all targets opportunistically,
 # 0: fetch on demand,
 # positive value: fetch that many targets opportunistically.
 # Enclose the list of numbers between quotes ("").
 # target-fetch-policy: "3 2 1 0 0"

 # Harden against very small EDNS buffer sizes. 
 # harden-short-bufsize: no

 # Harden against unseemly large queries.
 # harden-large-queries: no

 # Harden against out of zone rrsets, to avoid spoofing attempts. 
   harden-glue: yes

 # Harden against receiving dnssec-stripped data. If you turn it
 # off, failing to validate dnskey data for a trustanchor will 
 # trigger insecure mode for that zone (like without a trustanchor).
 # Default on, which insists on dnssec data for trust-anchored zones.
   harden-dnssec-stripped: yes

 # Harden against queries that fall under dnssec-signed nxdomain names.
 # harden-below-nxdomain: no

 # Harden the referral path by performing additional queries for
 # infrastructure data. Validates the replies (if possible).
 # Default off, because the lookups burden the server. Experimental 
 # implementation of draft-wijngaards-dnsext-resolver-side-mitigation.
 # harden-referral-path: no

 # Use 0x20-encoded random bits in the query to foil spoof attempts.
 # This feature is an experimental implementation of draft dns-0x20.
 # use-caps-for-id: no

 # Enforce privacy of these addresses. Strips them away from answers. 
 # It may cause DNSSEC validation to additionally mark it as bogus. 
 # Protects against 'DNS Rebinding' (uses browser as network proxy). 
 # Only 'private-domain' and 'local-data' names are allowed to have 
 # these private addresses. No default.
   private-address: 10.0.0.0/8
   private-address: 172.16.0.0/12
   private-address: 192.168.0.0/16
   private-address: 169.254.0.0/16
   private-address: fd00::/8
   private-address: fe80::/10

 # Allow the domain (and its subdomains) to contain private addresses.
 # local-data statements are allowed to contain private addresses too.
   private-domain: "loga.us"

 # If nonzero, unwanted replies are not only reported in statistics,
 # but also a running total is kept per thread. If it reaches the
 # threshold, a warning is printed and a defensive action is taken,
 # the cache is cleared to flush potential poison out of it.
 # A suggested value is 10000000, the default is 0 (turned off).
 # unwanted-reply-threshold: 0

 # Do not query the following addresses. No DNS queries are sent there.
 # List one address per entry. List classless netblocks with /size,
 # do-not-query-address: 127.0.0.1/8
 # do-not-query-address: ::1

 # if yes, the above default do-not-query-address entries are present.
 # if no, localhost can be queried (for testing and debugging).
 # Only needed if localhost (127.0.0.1@port) is used as stub-addr in stub zone
 #  do-not-query-localhost: no 

 # if yes, perform prefetching of almost expired message cache entries.
 # prefetch: no

 # if yes, perform key lookups adjacent to normal lookups.
 # prefetch-key: no

 # if yes, Unbound rotates RRSet order in response.
 # rrset-roundrobin: no

 # if yes, Unbound doesn't insert authority/additional sections
 # into response messages when those sections are not required.
 # minimal-responses: no

 # module configuration of the server. A string with identifiers
 # separated by spaces. "iterator" or "validator iterator"
 # module-config: "validator iterator"

 # File with trusted keys, kept uptodate using RFC5011 probes,
 # initial file like trust-anchor-file, then it stores metadata.
 # Use several entries, one per domain name, to track multiple zones.
 #
 # If you want to perform DNSSEC validation, run unbound-anchor before
 # you start unbound (i.e. in the system boot scripts). And enable:
 # Please note usage of unbound-anchor root anchor is at your own risk
 # and under the terms of our LICENSE (see that file in the source).
   auto-trust-anchor-file: "/usr/local/etc/unbound/root.key"

 # File with DLV trusted keys. Same format as trust-anchor-file.
 # There can be only one DLV configured, it is trusted from root down.
 # Download http://ftp.isc.org/www/dlv/dlv.isc.org.key
 # dlv-anchor-file: "dlv.isc.org.key"

 # File with trusted keys for validation. Specify more than one file
 # with several entries, one file per entry.
 # Zone file format, with DS and DNSKEY entries.
 # Note this gets out of date, use auto-trust-anchor-file please.
 # trust-anchor-file: ""
 
 # Trusted key for validation. DS or DNSKEY. specify the RR on a
 # single line, surrounded by "". TTL is ignored. class is IN default.
 # Note this gets out of date, use auto-trust-anchor-file please.
 # (These examples are from August 2007 and may not be valid anymore).
 # trust-anchor: "nlnetlabs.nl. DNSKEY 257 3 5 AQPzzTWMz8qSWIQlfRnPckx2BiVmkVN6LPupO3mbz7FhLSnm26n6iG9N Lby97Ji453aWZY3M5/xJBSOS2vWtco2t8C0+xeO1bc/d6ZTy32DHchpW 6rDH1vp86Ll+ha0tmwyy9QP7y2bVw5zSbFCrefk8qCUBgfHm9bHzMG1U BYtEIQ=="
 # trust-anchor: "jelte.nlnetlabs.nl. DS 42860 5 1 14D739EB566D2B1A5E216A0BA4D17FA9B038BE4A"

 # File with trusted keys for validation. Specify more than one file
 # with several entries, one file per entry. Like trust-anchor-file
 # but has a different file format. Format is BIND-9 style format, 
 # the trusted-keys { name flag proto algo "key"; }; clauses are read.
 # you need external update procedures to track changes in keys.
 # trusted-keys-file: ""

 # Ignore chain of trust. Domain is treated as insecure.
   domain-insecure: "loga.us"
   domain-insecure: "0.168.192.in-addr.arpa"

 # Override the date for validation with a specific fixed date.
 # Do not set this unless you are debugging signature inception
 # and expiration. "" or "0" turns the feature off. -1 ignores date.
 # val-override-date: ""

 # The time to live for bogus data, rrsets and messages. This avoids
 # some of the revalidation, until the time interval expires. in secs.
 # val-bogus-ttl: 60

 # The signature inception and expiration dates are allowed to be off
 # by 10% of the signature lifetime (expir-incep) from our local clock.
 # This leeway is capped with a minimum and a maximum. In seconds.
 # val-sig-skew-min: 3600
 # val-sig-skew-max: 86400

 # Should additional section of secure message also be kept clean of
 # unsecure data. Useful to shield the users of this validator from
 # potential bogus data in the additional section. All unsigned data 
 # in the additional section is removed from secure messages.
   val-clean-additional: yes

 # Turn permissive mode on to permit bogus messages. Thus, messages
 # for which security checks failed will be returned to clients,
 # instead of SERVFAIL. It still performs the security checks, which
 # result in interesting log files and possibly the AD bit in
 # replies if the message is found secure. The default is off.
 # val-permissive-mode: no

 # Ignore the CD flag in incoming queries and refuse them bogus data.
 # Enable it if the only clients of unbound are legacy servers (w2008)
 # that set CD but cannot validate themselves.
 # ignore-cd-flag: no

 # Have the validator log failed validations for your diagnosis.
 # 0: off. 1: A line per failed user query. 2: With reason and bad IP.
 # val-log-level: 0

 # It is possible to configure NSEC3 maximum iteration counts per
 # keysize. Keep this table very short, as linear search is done.
 # A message with an NSEC3 with larger count is marked insecure.
 # List in ascending order the keysize and count values.
 # val-nsec3-keysize-iterations: "1024 150 2048 500 4096 2500"
 
 # instruct the auto-trust-anchor-file probing to add anchors after ttl.
 # add-holddown: 2592000 # 30 days

 # instruct the auto-trust-anchor-file probing to del anchors after ttl.
 # del-holddown: 2592000 # 30 days

 # auto-trust-anchor-file probing removes missing anchors after ttl.
 # If the value 0 is given, missing anchors are not removed.
 # keep-missing: 31622400 # 366 days

 # the amount of memory to use for the key cache.
 # plain value in bytes or you can append k, m or G. default is "4Mb". 
 # key-cache-size: 4m

 # the number of slabs to use for the key cache.
 # the number of slabs must be a power of 2.
 # more slabs reduce lock contention, but fragment memory usage.
 # key-cache-slabs: 4

 # the amount of memory to use for the negative cache (used for DLV).
 # plain value in bytes or you can append k, m or G. default is "1Mb". 
 # neg-cache-size: 1m

 # By default, for a number of zones a small default 'nothing here'
 # reply is built-in. Query traffic is thus blocked. If you
 # wish to serve such zone you can unblock them by uncommenting one
 # of the nodefault statements below.
 # You may also have to use domain-insecure: zone to make DNSSEC work,
 # unless you have your own trust anchors for this zone.
 # local-zone: "localhost." nodefault
 # local-zone: "127.in-addr.arpa." nodefault
 # local-zone: "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa." nodefault
 # local-zone: "10.in-addr.arpa." nodefault
 # local-zone: "16.172.in-addr.arpa." nodefault
 # local-zone: "17.172.in-addr.arpa." nodefault
 # local-zone: "18.172.in-addr.arpa." nodefault
 # local-zone: "19.172.in-addr.arpa." nodefault
 # local-zone: "20.172.in-addr.arpa." nodefault
 # local-zone: "21.172.in-addr.arpa." nodefault
 # local-zone: "22.172.in-addr.arpa." nodefault
 # local-zone: "23.172.in-addr.arpa." nodefault
 # local-zone: "24.172.in-addr.arpa." nodefault
 # local-zone: "25.172.in-addr.arpa." nodefault
 # local-zone: "26.172.in-addr.arpa." nodefault
 # local-zone: "27.172.in-addr.arpa." nodefault
 # local-zone: "28.172.in-addr.arpa." nodefault
 # local-zone: "29.172.in-addr.arpa." nodefault
 # local-zone: "30.172.in-addr.arpa." nodefault
 # local-zone: "31.172.in-addr.arpa." nodefault
   local-zone: "168.192.in-addr.arpa." nodefault
 # local-zone: "0.in-addr.arpa." nodefault
 # local-zone: "254.169.in-addr.arpa." nodefault
 # local-zone: "2.0.192.in-addr.arpa." nodefault
 # local-zone: "100.51.198.in-addr.arpa." nodefault
 # local-zone: "113.0.203.in-addr.arpa." nodefault
 # local-zone: "255.255.255.255.in-addr.arpa." nodefault
 # local-zone: "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa." nodefault
 # local-zone: "d.f.ip6.arpa." nodefault
 # local-zone: "8.e.f.ip6.arpa." nodefault
 # local-zone: "9.e.f.ip6.arpa." nodefault
 # local-zone: "a.e.f.ip6.arpa." nodefault
 # local-zone: "b.e.f.ip6.arpa." nodefault
 # local-zone: "8.b.d.0.1.0.0.2.ip6.arpa." nodefault

 # a number of locally served zones can be configured.
 # local-zone: <zone> <type>
 # local-data: "<resource record string>"
 # o deny serves local data (if any), else, drops queries. 
 # o refuse serves local data (if any), else, replies with error.
 # o static serves local data, else, nxdomain or nodata answer.
 # o transparent gives local data, but resolves normally for other names
 # o redirect serves the zone data for any subdomain in the zone.
 # o nodefault can be used to normally resolve AS112 zones.
 # o typetransparent resolves normally for other types and other names
 #
 # defaults are localhost address, reverse for 127.0.0.1 and ::1
 # and nxdomain for AS112 zones. If you configure one of these zones
 # the default content is omitted, or you can omit it with 'nodefault'.
 # 
 # If you configure local-data without specifying local-zone, by
 # default a transparent local-zone is created for the data.
 #
 # You can add locally served data with
 # local-zone: "local." static
 # local-data: "mycomputer.local. IN A 192.0.2.51"
 # local-data: 'mytext.local TXT "content of text record"'
 #
 # You can override certain queries with
 # local-data: "adserver.example.com A 127.0.0.1"
 #
 # You can redirect a domain to a fixed address with
 # (this makes example.com, www.example.com, etc, all go to 192.0.2.3)
 # local-zone: "example.com" redirect
 # local-data: "example.com A 192.0.2.3"
 #
 # Shorthand to make PTR records, "IPv4 name" or "IPv6 name".
 # You can also add PTR records using local-data directly, but then
 # you need to do the reverse notation yourself.
 # local-data-ptr: "192.0.2.3 www.example.com"

 # service clients over SSL (on the TCP sockets), with plain DNS inside
 # the SSL stream. Give the certificate to use and private key.
 # default is "" (disabled). requires restart to take effect.
 # ssl-service-key: "path/to/privatekeyfile.key"
 # ssl-service-pem: "path/to/publiccertfile.pem"
 # ssl-port: 443

 # request upstream over SSL (with plain DNS inside the SSL stream).
 # Default is no. Can be turned on and off with unbound-control.
 # ssl-upstream: no

 # Python config section. To enable:
 # o use --with-pythonmodule to configure before compiling.
 # o list python in the module-config string (above) to enable.
 # o and give a python-script to run.

 python:

 # Script file to load
 # python-script: "/usr/local/etc/unbound/ubmodule-tst.py"

 # Remote control config section. 

 remote-control:

 # Enable remote control with unbound-control(8) here.
 # set up the keys and certificates with unbound-control-setup.
   control-enable: yes

 # what interfaces are listened to for remote control.
 # give 0.0.0.0 and ::0 to listen to all interfaces.
   control-interface: 127.0.0.1
 # control-interface: ::1

 # port number for remote control operations.
   control-port: 8953

 # unbound server key file.
   server-key-file: "/usr/local/etc/unbound/unbound_server.key"

 # unbound server certificate file.
   server-cert-file: "/usr/local/etc/unbound/unbound_server.pem"

 # unbound-control key file.
   control-key-file: "/usr/local/etc/unbound/unbound_control.key"

 # unbound-control certificate file.
   control-cert-file: "/usr/local/etc/unbound/unbound_control.pem"

 # Stub zones.
 # Create entries like below, to make all queries for 'example.com' and 
 # 'example.org' go to the given list of nameservers. list zero or more 
 # nameservers by hostname or by ipaddress. If you set stub-prime to yes, 
 # the list is treated as priming hints (default is no).
 # With stub-first yes, it attempts without the stub if it fails.
 # stub-zone:
 # name: "example.com"
 # stub-addr: 192.0.2.68
 # stub-prime: no
 # stub-first: no
 # stub-zone:
 # name: "example.org"
 # stub-host: ns.example.com.

   stub-zone:
   name: "loga.us"
   stub-addr: 192.168.0.220@5053

   stub-zone:
   name: "0.168.192.in-addr.arpa."
   stub-addr: 192.168.0.220@5053

# Forward zones
# Create entries like below, to make all queries for 'example.com' and
# 'example.org' go to the given list of servers. These servers have to handle
# recursion to other nameservers. List zero or more nameservers by hostname
# or by ipaddress. Use an entry with name "." to forward all queries.
# If you enable forward-first, it attempts without the forward if it fails.
# forward-zone:
# name: "example.com"
# forward-addr: 192.0.2.68
# forward-addr: 192.0.2.73@5355 # forward to port 5355.
# forward-first: no
# forward-zone:
# name: "example.org"
# forward-host: fwd.example.com

  forward-zone:
  name: "."
  forward-addr: 68.105.28.12
  forward-addr: 68.105.29.11
  forward-addr: 8.8.8.8

 

Here’s the complete /usr/local/etc/unbound/unbound.conf file for Server 2:

Note:  Please refer to the uncommented statements and adjust to your environment.

 

 #
 # Server bsd222.loga.us
 #
 # See unbound.conf(5) man page, version 1.4.22.
 #
 # this is a comment.

 # Use this to include other text into the file.
 # include: "otherfile.conf"

 # The server clause sets the main parameters. 

server:

 # whitespace is not necessary, but looks cleaner.

 # verbosity number, 0 is least verbose. 1 is default.
   verbosity: 1

 # print statistics to the log (for every thread) every N seconds.
 # Set to "" or 0 to disable. Default is disabled.
 # statistics-interval: 0

 # enable cumulative statistics, without clearing them after printing.
 # statistics-cumulative: no

 # enable extended statistics (query types, answer codes, status)
 # printed from unbound-control. default off, because of speed.
 # extended-statistics: no

 # number of threads to create. 1 disables threading.
   num-threads: 1

 # specify the interfaces to answer queries from by ip-address.
 # The default is to listen to localhost (127.0.0.1 and ::1).
 # specify 0.0.0.0 and ::0 to bind to all available interfaces.
 # specify every interface[@port] on a new 'interface:' labelled line.
 # The listen interfaces are not changed on reload, only on restart.
 # interface: 192.0.2.153
 # interface: 192.0.2.154
 # interface: 192.0.2.154@5003
 # interface: 2001:DB8::5
   interface: 127.0.0.1
   interface: 192.168.0.222
 
 # enable this feature to copy the source address of queries to reply.
 # Socket options are not supported on all platforms. experimental. 
 # interface-automatic: no

 # port to answer queries from
   port: 53

 # specify the interfaces to send outgoing queries to authoritative
 # server from by ip-address. If none, the default (all) interface
 # is used. Specify every interface on a 'outgoing-interface:' line.
 # outgoing-interface: 192.0.2.153
 # outgoing-interface: 2001:DB8::5
 # outgoing-interface: 2001:DB8::6

 # number of ports to allocate per thread, determines the size of the
 # port range that can be open simultaneously. About double the
 # num-queries-per-thread, or, use as many as the OS will allow you.
 # outgoing-range: 4096

 # permit unbound to use this port number or port range for
 # making outgoing queries, using an outgoing interface.
 # outgoing-port-permit: 32768

 # deny unbound the use this of port number or port range for
 # making outgoing queries, using an outgoing interface.
 # Use this to make sure unbound does not grab a UDP port that some
 # other server on this computer needs. The default is to avoid
 # IANA-assigned port numbers.
 # If multiple outgoing-port-permit and outgoing-port-avoid options
 # are present, they are processed in order.
 # outgoing-port-avoid: "3200-3208"

 # number of outgoing simultaneous tcp buffers to hold per thread.
 # outgoing-num-tcp: 10

 # number of incoming simultaneous tcp buffers to hold per thread.
 # incoming-num-tcp: 10

 # buffer size for UDP port 53 incoming (SO_RCVBUF socket option).
 # 0 is system default. Use 4m to catch query spikes for busy servers.
   so-rcvbuf: 1m

 # buffer size for UDP port 53 outgoing (SO_SNDBUF socket option).
 # 0 is system default. Use 4m to handle spikes on very busy servers.
   so-sndbuf: 1m 
 
 # on Linux(3.9+) use SO_REUSEPORT to distribute queries over threads.
 # so-reuseport: no

 # EDNS reassembly buffer to advertise to UDP peers (the actual buffer
 # is set with msg-buffer-size). 1480 can solve fragmentation (timeouts).
 # edns-buffer-size: 4096

 # Maximum UDP response size (not applied to TCP response).
 # Suggested values are 512 to 4096. Default is 4096. 65536 disables it.
 # max-udp-size: 4096

 # buffer size for handling DNS data. No messages larger than this
 # size can be sent or received, by UDP or TCP. In bytes.
 # msg-buffer-size: 65552

 # the amount of memory to use for the message cache.
 # plain value in bytes or you can append k, m or G. default is "4Mb". 
   msg-cache-size: 128m

 # the number of slabs to use for the message cache.
 # the number of slabs must be a power of 2.
 # more slabs reduce lock contention, but fragment memory usage.
 # msg-cache-slabs: 4

 # the number of queries that a thread gets to service.
 # num-queries-per-thread: 1024

 # if very busy, 50% queries run to completion, 50% get timeout in msec
 # jostle-timeout: 200
 
 # msec to wait before close of port on timeout UDP. 0 disables.
 # delay-close: 0

 # the amount of memory to use for the RRset cache.
 # plain value in bytes or you can append k, m or G. default is "4Mb". 
   rrset-cache-size: 256m

 # the number of slabs to use for the RRset cache.
 # the number of slabs must be a power of 2.
 # more slabs reduce lock contention, but fragment memory usage.
 # rrset-cache-slabs: 4

 # the time to live (TTL) value lower bound, in seconds. Default 0.
 # If more than an hour could easily give trouble due to stale data.
 # cache-min-ttl: 0

 # the time to live (TTL) value cap for RRsets and messages in the
 # cache. Items are not cached for longer. In seconds.
 # cache-max-ttl: 86400

 # the time to live (TTL) value for cached roundtrip times, lameness and
 # EDNS version information for hosts. In seconds.
 # infra-host-ttl: 900

 # the number of slabs to use for the Infrastructure cache.
 # the number of slabs must be a power of 2.
 # more slabs reduce lock contention, but fragment memory usage.
 # infra-cache-slabs: 4 

 # the maximum number of hosts that are cached (roundtrip, EDNS, lame).
 # infra-cache-numhosts: 10000

 # Enable IPv4, "yes" or "no".
   do-ip4: yes

 # Enable IPv6, "yes" or "no".
 # do-ip6: yes

 # Enable UDP, "yes" or "no".
   do-udp: yes

 # Enable TCP, "yes" or "no".
   do-tcp: yes

 # upstream connections use TCP only (and no UDP), "yes" or "no"
 # useful for tunneling scenarios, default no.
 # tcp-upstream: no

 # Detach from the terminal, run in background, "yes" or "no".
 # do-daemonize: yes

 # control which clients are allowed to make (recursive) queries
 # to this server. Specify classless netblocks with /size and action.
 # By default everything is refused, except for localhost.
 # Choose deny (drop message), refuse (polite error reply),
 # allow (recursive ok), allow_snoop (recursive and nonrecursive ok)
 # deny_non_local (drop queries unless can be answered from local-data)
 # refuse_non_local (like deny_non_local but polite error reply).
 # access-control: 0.0.0.0/0 refuse
 # access-control: 127.0.0.0/8 allow
 # access-control: ::0/0 refuse
 # access-control: ::1 allow
 # access-control: ::ffff:127.0.0.1 allow
   access-control: 127.0.0.0/8 allow
   access-control: 192.168.0.0/24 allow

 # if given, a chroot(2) is done to the given directory.
 # i.e. you can chroot to the working directory, for example,
 # for extra security, but make sure all files are in that directory.
 #
 # If chroot is enabled, you should pass the configfile (from the
 # commandline) as a full path from the original root. After the
 # chroot has been performed the now defunct portion of the config 
 # file path is removed to be able to reread the config after a reload. 
 #
 # All other file paths (working dir, logfile, roothints, and
 # key files) can be specified in several ways:
 # o as an absolute path relative to the new root.
 # o as a relative path to the working directory.
 # o as an absolute path relative to the original root.
 # In the last case the path is adjusted to remove the unused portion.
 #
 # The pid file can be absolute and outside of the chroot, it is 
 # written just prior to performing the chroot and dropping permissions.
 #
 # Additionally, unbound may need to access /dev/random (for entropy).
 # How to do this is specific to your OS.
 #
 # If you give "" no chroot is performed. The path must not end in a /.
   chroot: "/usr/local/etc/unbound"

 # if given, user privileges are dropped (after binding port),
 # and the given username is assumed. Default is user "unbound".
 # If you give "" no privileges are dropped.
   username: "unbound"

 # the working directory. The relative files in this config are 
 # relative to this directory. If you give "" the working directory
 # is not changed.
   directory: "/usr/local/etc/unbound"

 # the log file, "" means log to stderr. 
 # Use of this option sets use-syslog to "no".
   logfile: "/usr/local/etc/unbound/log/unbound.log"

 # Log to syslog(3) if yes. The log facility LOG_DAEMON is used to 
 # log to, with identity "unbound". If yes, it overrides the logfile.
 # use-syslog: yes 

 # print UTC timestamp in ascii to logfile, default is epoch in seconds.
   log-time-ascii: yes 
 
 # print one line with time, IP, name, type, class for every query.
 # log-queries: no

 # the pid file. Can be an absolute path outside of chroot/work dir.
   pidfile: "/usr/local/etc/unbound/unbound.pid"

 # file to read root hints from.
 # get one from ftp://FTP.INTERNIC.NET/domain/named.cache
   root-hints: "/usr/local/etc/unbound/root.hints"

 # enable to not answer id.server and hostname.bind queries.
   hide-identity: yes 

 # enable to not answer version.server and version.bind queries.
   hide-version: yes 

 # the identity to report. Leave "" or default to return hostname.
 # identity: ""

 # the version to report. Leave "" or default to return package version.
 # version: ""

 # the target fetch policy.
 # series of integers describing the policy per dependency depth. 
 # The number of values in the list determines the maximum dependency 
 # depth the recursor will pursue before giving up. Each integer means:
 # -1 : fetch all targets opportunistically,
 # 0: fetch on demand,
 # positive value: fetch that many targets opportunistically.
 # Enclose the list of numbers between quotes ("").
 # target-fetch-policy: "3 2 1 0 0"

 # Harden against very small EDNS buffer sizes. 
 # harden-short-bufsize: no

 # Harden against unseemly large queries.
 # harden-large-queries: no

 # Harden against out of zone rrsets, to avoid spoofing attempts. 
   harden-glue: yes

 # Harden against receiving dnssec-stripped data. If you turn it
 # off, failing to validate dnskey data for a trustanchor will 
 # trigger insecure mode for that zone (like without a trustanchor).
 # Default on, which insists on dnssec data for trust-anchored zones.
   harden-dnssec-stripped: yes

 # Harden against queries that fall under dnssec-signed nxdomain names.
 # harden-below-nxdomain: no

 # Harden the referral path by performing additional queries for
 # infrastructure data. Validates the replies (if possible).
 # Default off, because the lookups burden the server. Experimental 
 # implementation of draft-wijngaards-dnsext-resolver-side-mitigation.
 # harden-referral-path: no

 # Use 0x20-encoded random bits in the query to foil spoof attempts.
 # This feature is an experimental implementation of draft dns-0x20.
 # use-caps-for-id: no

 # Enforce privacy of these addresses. Strips them away from answers. 
 # It may cause DNSSEC validation to additionally mark it as bogus. 
 # Protects against 'DNS Rebinding' (uses browser as network proxy). 
 # Only 'private-domain' and 'local-data' names are allowed to have 
 # these private addresses. No default.
   private-address: 10.0.0.0/8
   private-address: 172.16.0.0/12
   private-address: 192.168.0.0/16
   private-address: 169.254.0.0/16
   private-address: fd00::/8
   private-address: fe80::/10

 # Allow the domain (and its subdomains) to contain private addresses.
 # local-data statements are allowed to contain private addresses too.
   private-domain: "loga.us"

 # If nonzero, unwanted replies are not only reported in statistics,
 # but also a running total is kept per thread. If it reaches the
 # threshold, a warning is printed and a defensive action is taken,
 # the cache is cleared to flush potential poison out of it.
 # A suggested value is 10000000, the default is 0 (turned off).
 # unwanted-reply-threshold: 0

 # Do not query the following addresses. No DNS queries are sent there.
 # List one address per entry. List classless netblocks with /size,
 # do-not-query-address: 127.0.0.1/8
 # do-not-query-address: ::1

 # if yes, the above default do-not-query-address entries are present.
 # if no, localhost can be queried (for testing and debugging).
 # Only needed if localhost (127.0.0.1@port) is used as stub-addr in stub zone
 # do-not-query-localhost: no 

 # if yes, perform prefetching of almost expired message cache entries.
 # prefetch: no

 # if yes, perform key lookups adjacent to normal lookups.
 # prefetch-key: no

 # if yes, Unbound rotates RRSet order in response.
 # rrset-roundrobin: no

 # if yes, Unbound doesn't insert authority/additional sections
 # into response messages when those sections are not required.
 # minimal-responses: no

 # module configuration of the server. A string with identifiers
 # separated by spaces. "iterator" or "validator iterator"
 # module-config: "validator iterator"

 # File with trusted keys, kept uptodate using RFC5011 probes,
 # initial file like trust-anchor-file, then it stores metadata.
 # Use several entries, one per domain name, to track multiple zones.
 #
 # If you want to perform DNSSEC validation, run unbound-anchor before
 # you start unbound (i.e. in the system boot scripts). And enable:
 # Please note usage of unbound-anchor root anchor is at your own risk
 # and under the terms of our LICENSE (see that file in the source).
   auto-trust-anchor-file: "/usr/local/etc/unbound/root.key"

 # File with DLV trusted keys. Same format as trust-anchor-file.
 # There can be only one DLV configured, it is trusted from root down.
 # Download http://ftp.isc.org/www/dlv/dlv.isc.org.key
 # dlv-anchor-file: "dlv.isc.org.key"

 # File with trusted keys for validation. Specify more than one file
 # with several entries, one file per entry.
 # Zone file format, with DS and DNSKEY entries.
 # Note this gets out of date, use auto-trust-anchor-file please.
 # trust-anchor-file: ""
 
 # Trusted key for validation. DS or DNSKEY. specify the RR on a
 # single line, surrounded by "". TTL is ignored. class is IN default.
 # Note this gets out of date, use auto-trust-anchor-file please.
 # (These examples are from August 2007 and may not be valid anymore).
 # trust-anchor: "nlnetlabs.nl. DNSKEY 257 3 5 AQPzzTWMz8qSWIQlfRnPckx2BiVmkVN6LPupO3mbz7FhLSnm26n6iG9N Lby97Ji453aWZY3M5/xJBSOS2vWtco2t8C0+xeO1bc/d6ZTy32DHchpW 6rDH1vp86Ll+ha0tmwyy9QP7y2bVw5zSbFCrefk8qCUBgfHm9bHzMG1U BYtEIQ=="
 # trust-anchor: "jelte.nlnetlabs.nl. DS 42860 5 1 14D739EB566D2B1A5E216A0BA4D17FA9B038BE4A"

 # File with trusted keys for validation. Specify more than one file
 # with several entries, one file per entry. Like trust-anchor-file
 # but has a different file format. Format is BIND-9 style format, 
 # the trusted-keys { name flag proto algo "key"; }; clauses are read.
 # you need external update procedures to track changes in keys.
 # trusted-keys-file: ""

 # Ignore chain of trust. Domain is treated as insecure.
   domain-insecure: "loga.us"
   domain-insecure: "0.168.192.in-addr.arpa."

 # Override the date for validation with a specific fixed date.
 # Do not set this unless you are debugging signature inception
 # and expiration. "" or "0" turns the feature off. -1 ignores date.
 # val-override-date: ""

 # The time to live for bogus data, rrsets and messages. This avoids
 # some of the revalidation, until the time interval expires. in secs.
 # val-bogus-ttl: 60

 # The signature inception and expiration dates are allowed to be off
 # by 10% of the signature lifetime (expir-incep) from our local clock.
 # This leeway is capped with a minimum and a maximum. In seconds.
 # val-sig-skew-min: 3600
 # val-sig-skew-max: 86400

 # Should additional section of secure message also be kept clean of
 # unsecure data. Useful to shield the users of this validator from
 # potential bogus data in the additional section. All unsigned data 
 # in the additional section is removed from secure messages.
   val-clean-additional: yes

 # Turn permissive mode on to permit bogus messages. Thus, messages
 # for which security checks failed will be returned to clients,
 # instead of SERVFAIL. It still performs the security checks, which
 # result in interesting log files and possibly the AD bit in
 # replies if the message is found secure. The default is off.
 # val-permissive-mode: no

 # Ignore the CD flag in incoming queries and refuse them bogus data.
 # Enable it if the only clients of unbound are legacy servers (w2008)
 # that set CD but cannot validate themselves.
 # ignore-cd-flag: no

 # Have the validator log failed validations for your diagnosis.
 # 0: off. 1: A line per failed user query. 2: With reason and bad IP.
 # val-log-level: 0

 # It is possible to configure NSEC3 maximum iteration counts per
 # keysize. Keep this table very short, as linear search is done.
 # A message with an NSEC3 with larger count is marked insecure.
 # List in ascending order the keysize and count values.
 # val-nsec3-keysize-iterations: "1024 150 2048 500 4096 2500"
 
 # instruct the auto-trust-anchor-file probing to add anchors after ttl.
 # add-holddown: 2592000 # 30 days

 # instruct the auto-trust-anchor-file probing to del anchors after ttl.
 # del-holddown: 2592000 # 30 days

 # auto-trust-anchor-file probing removes missing anchors after ttl.
 # If the value 0 is given, missing anchors are not removed.
 # keep-missing: 31622400 # 366 days

 # the amount of memory to use for the key cache.
 # plain value in bytes or you can append k, m or G. default is "4Mb". 
 # key-cache-size: 4m

 # the number of slabs to use for the key cache.
 # the number of slabs must be a power of 2.
 # more slabs reduce lock contention, but fragment memory usage.
 # key-cache-slabs: 4

 # the amount of memory to use for the negative cache (used for DLV).
 # plain value in bytes or you can append k, m or G. default is "1Mb". 
 # neg-cache-size: 1m

 # By default, for a number of zones a small default 'nothing here'
 # reply is built-in. Query traffic is thus blocked. If you
 # wish to serve such zone you can unblock them by uncommenting one
 # of the nodefault statements below.
 # You may also have to use domain-insecure: zone to make DNSSEC work,
 # unless you have your own trust anchors for this zone.
 # local-zone: "localhost." nodefault
 # local-zone: "127.in-addr.arpa." nodefault
 # local-zone: "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa." nodefault
 # local-zone: "10.in-addr.arpa." nodefault
 # local-zone: "16.172.in-addr.arpa." nodefault
 # local-zone: "17.172.in-addr.arpa." nodefault
 # local-zone: "18.172.in-addr.arpa." nodefault
 # local-zone: "19.172.in-addr.arpa." nodefault
 # local-zone: "20.172.in-addr.arpa." nodefault
 # local-zone: "21.172.in-addr.arpa." nodefault
 # local-zone: "22.172.in-addr.arpa." nodefault
 # local-zone: "23.172.in-addr.arpa." nodefault
 # local-zone: "24.172.in-addr.arpa." nodefault
 # local-zone: "25.172.in-addr.arpa." nodefault
 # local-zone: "26.172.in-addr.arpa." nodefault
 # local-zone: "27.172.in-addr.arpa." nodefault
 # local-zone: "28.172.in-addr.arpa." nodefault
 # local-zone: "29.172.in-addr.arpa." nodefault
 # local-zone: "30.172.in-addr.arpa." nodefault
 # local-zone: "31.172.in-addr.arpa." nodefault
   local-zone: "168.192.in-addr.arpa." nodefault
 # local-zone: "0.in-addr.arpa." nodefault
 # local-zone: "254.169.in-addr.arpa." nodefault
 # local-zone: "2.0.192.in-addr.arpa." nodefault
 # local-zone: "100.51.198.in-addr.arpa." nodefault
 # local-zone: "113.0.203.in-addr.arpa." nodefault
 # local-zone: "255.255.255.255.in-addr.arpa." nodefault
 # local-zone: "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa." nodefault
 # local-zone: "d.f.ip6.arpa." nodefault
 # local-zone: "8.e.f.ip6.arpa." nodefault
 # local-zone: "9.e.f.ip6.arpa." nodefault
 # local-zone: "a.e.f.ip6.arpa." nodefault
 # local-zone: "b.e.f.ip6.arpa." nodefault
 # local-zone: "8.b.d.0.1.0.0.2.ip6.arpa." nodefault

 # a number of locally served zones can be configured.
 # local-zone: <zone> <type>
 # local-data: "<resource record string>"
 # o deny serves local data (if any), else, drops queries. 
 # o refuse serves local data (if any), else, replies with error.
 # o static serves local data, else, nxdomain or nodata answer.
 # o transparent gives local data, but resolves normally for other names
 # o redirect serves the zone data for any subdomain in the zone.
 # o nodefault can be used to normally resolve AS112 zones.
 # o typetransparent resolves normally for other types and other names
 #
 # defaults are localhost address, reverse for 127.0.0.1 and ::1
 # and nxdomain for AS112 zones. If you configure one of these zones
 # the default content is omitted, or you can omit it with 'nodefault'.
 # 
 # If you configure local-data without specifying local-zone, by
 # default a transparent local-zone is created for the data.
 #
 # You can add locally served data with
 # local-zone: "local." static
 # local-data: "mycomputer.local. IN A 192.0.2.51"
 # local-data: 'mytext.local TXT "content of text record"'
 #
 # You can override certain queries with
 # local-data: "adserver.example.com A 127.0.0.1"
 #
 # You can redirect a domain to a fixed address with
 # (this makes example.com, www.example.com, etc, all go to 192.0.2.3)
 # local-zone: "example.com" redirect
 # local-data: "example.com A 192.0.2.3"
 #
 # Shorthand to make PTR records, "IPv4 name" or "IPv6 name".
 # You can also add PTR records using local-data directly, but then
 # you need to do the reverse notation yourself.
 # local-data-ptr: "192.0.2.3 www.example.com"

 # service clients over SSL (on the TCP sockets), with plain DNS inside
 # the SSL stream. Give the certificate to use and private key.
 # default is "" (disabled). requires restart to take effect.
 # ssl-service-key: "path/to/privatekeyfile.key"
 # ssl-service-pem: "path/to/publiccertfile.pem"
 # ssl-port: 443

 # request upstream over SSL (with plain DNS inside the SSL stream).
 # Default is no. Can be turned on and off with unbound-control.
 # ssl-upstream: no

 # Python config section. To enable:
 # o use --with-pythonmodule to configure before compiling.
 # o list python in the module-config string (above) to enable.
 # o and give a python-script to run.

python:

 # Script file to load
 # python-script: "/usr/local/etc/unbound/ubmodule-tst.py"

 # Remote control config section. 

 remote-control:

 # Enable remote control with unbound-control(8) here.
 # set up the keys and certificates with unbound-control-setup.
   control-enable: yes

 # what interfaces are listened to for remote control.
 # give 0.0.0.0 and ::0 to listen to all interfaces.
   control-interface: 127.0.0.1
 # control-interface: ::1

 # port number for remote control operations.
   control-port: 8953

 # unbound server key file.
   server-key-file: "/usr/local/etc/unbound/unbound_server.key"

 # unbound server certificate file.
   server-cert-file: "/usr/local/etc/unbound/unbound_server.pem"

 # unbound-control key file.
   control-key-file: "/usr/local/etc/unbound/unbound_control.key"

 # unbound-control certificate file.
   control-cert-file: "/usr/local/etc/unbound/unbound_control.pem"

 # Stub zones.
 # Create entries like below, to make all queries for 'example.com' and 
 # 'example.org' go to the given list of nameservers. list zero or more 
 # nameservers by hostname or by ipaddress. If you set stub-prime to yes, 
 # the list is treated as priming hints (default is no).
 # With stub-first yes, it attempts without the stub if it fails.
 # stub-zone:
 # name: "example.com"
 # stub-addr: 192.0.2.68
 # stub-prime: no
 # stub-first: no
 # stub-zone:
 # name: "example.org"
 # stub-host: ns.example.com.

   stub-zone:
   name: "loga.us"
   stub-addr: 192.168.0.222@5053

   stub-zone:
   name: "0.168.192.in-addr.arpa."
   stub-addr: 192.168.0.222@5053

 # Forward zones
 # Create entries like below, to make all queries for 'example.com' and
 # 'example.org' go to the given list of servers. These servers have to handle
 # recursion to other nameservers. List zero or more nameservers by hostname
 # or by ipaddress. Use an entry with name "." to forward all queries.
 # If you enable forward-first, it attempts without the forward if it fails.
 # forward-zone:
 # name: "example.com"
 # forward-addr: 192.0.2.68
 # forward-addr: 192.0.2.73@5355 # forward to port 5355.
 # forward-first: no
 # forward-zone:
 # name: "example.org"
 # forward-host: fwd.example.com

   forward-zone:
   name: "."
   forward-addr: 68.105.28.12
   forward-addr: 68.105.29.11
   forward-addr: 8.8.8.8

 

Log Rotation:

Since Unbound will generate a substantial amount of log entries depending on the verbosity level, managing log rotation is imperative.  The below actions are needed on both servers if you are maintaining log files.

 

When Unbound first creates the log file, the file permissions are as follows:

-rw-r--r--  1 unbound  wheel    11086 Aug  2 16:15 unbound.log

 

Therefore, an entry in the /etc/newsyslog.conf file is necessary on each server:

/usr/local/etc/unbound/log/unbound.log  unbound:wheel     640  7     *    @T12  JBR   /usr/local/etc/unbound/log_reopen

 

The content of the /usr/local/etc/unbound/log_reopen script is as follows:

#!/bin/sh

#This script restarts Unbound after log rotation by newsyslog(8)

/usr/local/sbin/unbound-control -q log_reopen

exit 0

 

The permissions of /usr/local/etc/unbound/log_reopen need to be 744:

-rwxr--r--  1 unbound  wheel      135 Aug  2 09:28 log_reopen*

 

The file permissions on the log file and script are important in order for newsyslog to properly utilize the R flag and execute the script

Restart the newsyslog and unbound daemons.

# service unbound restart
# service newsyslog restart

 

Summary:

  • Unbound configured as a DNS Caching Server on Server 1 and Server 2
  • All DNS Queries are forwarded to external DNS Servers and cached by Unbound
  • All Private Domain DNS queries are forwarded to the Stub-Zone (NSD Server) on Port 5053
  • All LAN Clients can utilize Server 1 and Server 2 as their DNS Servers

 

In the future, the inclusion of statistics and threads will provide an interesting challenge.  Until then, please let me know if you discover any typos or mistakes.

In Part II, we will add NSD to our configuration in order to resolve our local or internal zone – loga.us.  This split-DNS configuration allows us to resolve hosts in the loga.us domain on our LAN as well as maintain hosts for loga.us in the public domain.

 

Additional References:

www.unbound.net

www.nlnetlabs.nl

calomel.org

www.prado.it/2012/04/23/how-to-configure-unbound-with-dnssec-validation-on-freebsd-9-0/

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