Periodic disconnections when behind workplace firewall
reddit / irc

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chloeia · 2017-09-26 06:48

I use Weechat to connect to my IRC channels. Once every week or so,
the connection gets repeatedly disconnected (it reconnects because I
have weechat setup to attempt re-connects), with the following
message:

    irc: reading data on socket: error -54 Error in the pull function.
    irc: disconnecting from server...
    irc: disconnected from server

Any idea why this might be happening?

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DMLloyd · 2017-09-26 14:28

Many workplaces block known IRC ports because IRC can be used by
botnet CnC servers to communicate with infected machines.  Does your
sysadmin know you're running IRC at work?

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chloeia · 2017-09-26 15:58

This only happens once in a while, so I don't know what to make of it.

Yes, I did tell my sysadmin about it. He's not very sure why such a
thing might be happening. They recently got a new Dell Sonicwall
firewall, and apparently haven't ironed out all its kinks.

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xnrand · 2017-09-26 20:11

New fancy firewall you say? It might be a stateful firewall keeping
track of all existing TCP connections and only allowing packets
through that match a connection it remembers.

It might have a maximum age of TCP connections (so that old dead
connections that were never properly closed do not pollute its RAM).
That sounds like the thing a "super fancy" ^^^totally ^^^not
^^^sarcastic firewall would do.

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chloeia · 2017-09-27 04:16

:) I see... If that is the case, what would a good resolution be?
Increase maximum age? But then how much? And that would make that
"feature" pointless. Is there any other way around it? My sysadmin
will probably at-least consider a suggestion.

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xnrand · 2017-09-27 20:43

Under the assumption that it's really caused by the problem that I
suspect, it 's possible to fix it:

If the firewall allows increasing the maximum age for IRC connections
only, that would be a solution with little to no performance impact.

If that's not supported, it might still be possible to "statically"
allow IRC connections (i.e. exempt IRC connections by port from the
stateful tracking) but that might open a hole in the firewall that you
don't want to open.

However, it might be caused by something else entirely, analyzing this
kind of problem can be complicated.