Maintained by: NLnet Labs

[Unbound-users] Does/can unbound use RTT values to prioritise DNS servers

Nick B
Sat Nov 27 20:21:08 CET 2010


I've a running installation of Unbound in the United Kingdom and it
seems to work well. However, with an empty cache it is notable that
some queries take longer than others. Using dig with the +trace option
it can be shown that it can take up to a second to respond.

Using ping the average response of the root servers are:

A.ROOT-SERVERS.NET - 106ms
B.ROOT-SERVERS.NET - 152ms
C.ROOT-SERVERS.NET - 94ms
D.ROOT-SERVERS.NET - 80ms
E.ROOT-SERVERS.NET - ??
F.ROOT-SERVERS.NET - 147ms
G.ROOT-SERVERS.NET - ??
H.ROOT-SERVERS.NET - ??
I.ROOT-SERVERS.NET - 35ms
J.ROOT-SERVERS.NET - 22ms
K.ROOT-SERVERS.NET - 1ms
L.ROOT-SERVERS.NET - 57ms
M.ROOT-SERVERS.NET - 247ms

Does or can unbound be configured to prioritise recursive queries
using the lowest RTT values, maybe from the Infra cache? In this
instance 'K' is preferable to 'M' for example.