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Setting up Unbound as an recursive caching DNS server

Unbound has been setup with the motivation of providing:

  • fast DNS resolution
  • IPv6 support
  • easy to configure and maintain

Unbound is part of the Fedora distribution, and for RHEL/CentOS it is part of the EPEL repository.

# yum install unbound

Configure the server for internal use only, bound to a specific address with the configuration file '/etc/unbound/unbound.conf':

server:
        verbosity: 1
        num-threads: 2

        interface: 10.20.2.5
        interface: 2001:4428:225:2::5

        access-control: 0.0.0.0/0 refuse
        access-control: 10.20.0.0/16 allow
        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: fe80::/10 allow
        access-control: 2001:4428:225::0/48 allow

        local-zone: "20.10.in-addr.arpa." transparent

stub-zone:
        name: "lucidsolutions.co.nz"
        stub-addr: 2001:4428:225:2::3
        stub-addr: 10.20.2.3

stub-zone:
       name: "20.10.in-addr.arpa"
       stub-addr: 2001:4428:225:2::3
       stub-addr: 10.20.2.3

stub-zone:
       name: "5.2.2.0.8.2.4.4.1.0.0.2.ip6.arpa"
       stub-addr: 2001:4428:225:2::3
       stub-addr: 10.20.2.3

Start the unbound service

# service unbound start

Links

Appendices

CentOS 5 RPM Installation

Dependencies Resolved

=========================================================================================
 Package                Arch             Version                    Repository      Size
=========================================================================================
Installing:
 unbound                x86_64           1.4.4-1.el5                epel           814 k
Installing for dependencies:
 ldns                   x86_64           1.6.4-4.el5                epel           447 k
 libevent               x86_64           1.4.13-1                   base           112 k
 libpcap                x86_64           14:0.9.4-15.el5            base           109 k
 unbound-libs           x86_64           1.4.4-1.el5                epel           261 k

Transaction Summary
=========================================================================================
Install       5 Package(s)
Upgrade       0 Package(s)

Total download size: 1.7 M

 

 

 

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