Maintained by: NLnet Labs

[Unbound-users] TCP and/or UDP used by resolver?

Patrik Fältström
Thu Aug 25 16:25:57 CEST 2011

Hi, I use the pylons package and see that one can set the transport mechanism via the set_usevc call. The argument is boolean and one set whether a virtual circuit can be used or not. What makes me confused is that I feel such a value should have three states: UDP/TCP with fallback, UDP only and TCP only.

I read the manual as if this (when true) uses TCP only, but if false uses UDP with fallback to TCP.

Or is the value to use UDP with fallback to TCP, but UDP only if false?

Can someone help with interpretation please?


P.S. In my code that test DNS I want to be able to set whether UDP or TCP is in use, with no fallback, but then I also have "normal" queries that can use whatever works (and I do not care what was used).

P.P.S. This is my part of the testing of pylons with Python3 and so far it works!