[zeromq-dev] ESTABLISHED connection mismatch

Garrett Smith g at rre.tt
Tue Apr 9 23:51:18 CEST 2013


No NATing that I'm aware of. But this is EC2, so there could be
shenanigans afoot. (Shenanigans btw, is the most advanced descriptor
in my network layer vocabulary.)

The 6 "established" connections on the router-server are still shown
via netstat -- even after these many hours have passed. If there's a
timeout in play, it's quite long.

On Tue, Apr 9, 2013 at 3:54 PM, Michel Pelletier
<pelletier.michel at gmail.com> wrote:
> Is there NATing between these two hosts? RFC 5382 has some guidelines on
> idle timeout for established connections, you might be hitting that limit.
>
> -Michel
>
>
> On Tue, Apr 9, 2013 at 9:36 AM, Garrett Smith <g at rre.tt> wrote:
>>
>> I don't know if this is a 0MQ question or a general networking
>> question. I know that I'm confused.
>>
>> I'm troubleshooting some message delivery problems and I've run across
>> this scenario:
>>
>> The ESTABLISHED tcp connections on one server don't match the
>> corresponding connections on the other server. I'll call one server
>> "router-server" and the other "dealer-server" (corresponding to the
>> role and 0MQ socket type one each server).
>>
>> On the "router-server" I see these connections to the "dealer-server":
>>
>> tcp        0      0 192.168.1.10:1234     192.168.1.11:52726
>> ESTABLISHED
>> tcp        0      0 192.168.1.10:1234     192.168.1.11:42556
>> ESTABLISHED
>> tcp        0      0 192.168.1.10:1234     192.168.1.11:52728
>> ESTABLISHED
>> tcp        0      0 192.168.1.10:1234     192.168.1.11:42774
>> ESTABLISHED
>> tcp        0      0 192.168.1.10:1234     192.168.1.11:52727
>> ESTABLISHED
>> tcp        0      0 192.168.1.10:1234     192.168.1.11:42563
>> ESTABLISHED
>>
>> On the "dealer-server" I see these to the "router-server":
>>
>> tcp        0      0 192.168.1.11:52728     192.168.1.10:1234
>> ESTABLISHED
>> tcp        0      0 192.168.1.11:42563     192.168.1.10:1234
>> ESTABLISHED
>> tcp        0      0 192.168.1.11:42556     192.168.1.10:1234
>> ESTABLISHED
>>
>> These were listed by "netstat -na" on the respective servers at the same
>> time.
>>
>> This scenario seems to only apply to the problem connection -- the
>> non-problem router/dealer server pairs have the expected one-to-one
>> established connections.
>>
>> Garrett
>> _______________________________________________
>> zeromq-dev mailing list
>> zeromq-dev at lists.zeromq.org
>> http://lists.zeromq.org/mailman/listinfo/zeromq-dev
>
>
>
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