1 Interfaces 2 ========== 3 4 NSD will by default bind itself to the system default interface and service IPv4 5 and if available also IPv6. It is possible to service only IPv4 or IPv6 using 6 the :option:`-4`, :option:`-6` command line options, or the ``ip4-only`` and 7 ``ip6-only`` config file options. 8 9 The command line option :option:`-a` and config file option ip-address can be 10 given to bind to specific interfaces. Multiple interfaces can be specified, 11 which is useful for two reasons: 12 13 - The specific interface bound will result in the OS bypassing routing tables 14 for the interface selection. This results in a small performance gain. It is 15 not the performance gain that is the problem: sometimes the routing tables can 16 give the wrong answer, see the next point. 17 - The answer will be routed via the interface the query came from. This makes 18 sure that the return address on the DNS replies is the same as the query was 19 sent to. Many resolvers require the source address of the replies to be 20 correct. The ``ip-address:`` option is easier than configuring the OS routing 21 table to return the DNS replies via the correct interface. 22 23 The above means that even for systems with multiple interfaces where you intend 24 to provide DNS service to all interfaces, it is prudent to specify all the 25 interfaces as ``ip-address`` config file options. 26 27 With the config file option ``ip-transparent`` you can allow NSD to bind to 28 non-local addresses.
Indexes created Wed Mar 04 15:26:31 UTC 2026