Recursive DNS servers

The struck-through names in the tables below are old names that are being deprecated as part of our renaming and renumbering project.

Default resolvers

These are the usual recommended DNS servers; for example, you will be using these servers if you connect to Wi-Fi / eduroam.

They implement DNS RPZ blocks and encrypted queries.

server names IPv4 IPv6
rec0.dns.cam.ac.uk
recdns0.csx.cam.ac.uk
131.111.8.42 2001:630:212:8::d:0
rec1.dns.cam.ac.uk
recdns1.csx.cam.ac.uk
131.111.12.20 2001:630:212:12::d:1

Pass-through resolvers

There are alternative DNS server addresses hosted on the same hardware as the default resolvers. These are available if you need un-blocked access to the DNS. They also provide encrypted queries.

If a legitimate site is blocked and this is causing problems for you, please report the error to CamCERT rather than switching to the pass-through resolvers.

server names IPv4 IPv6
raw0.dns.cam.ac.uk 131.111.9.99 2001:630:212:8::d:2
raw1.dns.cam.ac.uk 131.111.12.99 2001:630:212:12::d:3