[OpenIndiana-discuss] ssh sessions timing out?

James Carlson carlsonj at workingcode.com
Thu Oct 13 13:43:52 UTC 2011


Dan Swartzendruber wrote:
> Yeah, I think that's it.  I happened to notice a few minutes ago that when I
> ssh to 'nas.druber.com', it is connecting via ipv6 and has the lag.  If I
> change the putty entry to 10.0.0.4, it connects instantly.  I am wondering
> now if the ssh issue is also ipv6 related?  I now have two ssh sessions
> open, one via ipv4 and one via ipv6.  I am running wireshark on the ipv4
> only at this point.  If the ipv6 one dies, I may retry wireshark on the ipv6
> address...

Actually, that sounds like a completely different problem, unrelated to
name services.  That sounds like IPv6 breakage.

Depending on the drivers involved, I remember there being various
hardware checksum offload bugs that can cause all sorts of
strange-looking problems.  Some were IPv6-specific.

It might be worthwhile to try rebooting with this in /etc/system:

	set ip:dohwcksum=0

and, if you're using e1000g, this in /kernel/drv/e1000g.conf:

	tx_hcksum_enable=0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0;
	lso_enable=0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0;

I don't trust hardware offload schemes any further than I can throw
them.  For a minuscule bump in performance, they extract many hours and
days of wasted administrative effort.

-- 
James Carlson         42.703N 71.076W         <carlsonj at workingcode.com>



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