I use SSH’s socks proxy feature a lot, in fact I use it all the time, most of my browsing, IM, etc all goes over it out via my hosted virtual machines,
I do this to simplify my life for things like firewall rules and also to get around things like age blocks on mobile networks. I work for a site deemed adult by most of them so I can’t even see my nagios without age verifying.
Recently they have been driving me nuts, every now and then the whole session would just lock up and sit there doing nothing, I’ve not seen this happen before and was a bit stumped.
Turns out, it chooses to speak to TCP/53 sometimes instead of UDP/53 for resolving, not sure why exactly, I’ve not tried to figure out what queries cause this – I know there are limits to response sizes which will force it to go over TCP. Why it’s only started doing this now I don’t know, maybe a update changed behavior, I’ve never had TCP/53 open on the cache.
My firewall was blocking TCP/53 on the local cache so this would lock up the whole ssh session, maybe the whole ssh process is single threaded and so waiting in SYN_SENT mode just hangs the whole thing, that’s a bit sucky, I might need a better proxy.
