Maintained by: NLnet Labs

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

Paul Wouters
Thu Aug 25 20:41:30 CEST 2011

On Thu, 25 Aug 2011, Patrik Fältström wrote:

> On 25 aug 2011, at 17:52, Paul Wouters wrote:
>> I think the easiest is to configure multiple unbound instances. One with defaults, one with do-tcp:no
>> In svn there is also the tcp-upstream:yes|no option that controls if tcp can be used by the resolver to obtain data (as opposed to the client method of accessing unbound itself)
> Hmm...I am using pyldns as a stub resolver, so what you suggest is not really helping.

have a look at;a=summary

If there is functionality you need exposed, Chris will be able to implement them for you.

I know he has usage cases where he sets TCP specifically. Though then you're not using unbound
(or its cache), as the client cannot tell the server how it should fetch results. And even if
we'd add such a flag, how would you deal with cached data?

If you are trying to figure out TCP or EDNS connectivity, you cannot really go through an
intermediate resolver (unless you're just testing this specific last mile resolver)

If you can tell us a bit more, perhaps we can help you, as we're doing similar things with
ldnsx on top of ldns-python.