Was SSHing to my home box and listed a directory-- connection froze. Closed that, went back and just did a "mount" to remind myself which disk that was on-- that froze too. Usually after printing a line or two of the output.
Finally remembered having had this before, and dropped the MTU of the ethernet card to 1000, and it worked fine. A bit of trial and error suggests the MTU needs to be somewhere around 1460, not 1500. Something to reconfigure on the router when I get home (its telnet interface seems to be borked) but a fun one to sort out; odd that I'd never encountered that one when using the machine from home though. I guess I haven't been uploading large blocks of data. Maybe Windows sets a lower MTU by default? Although I do most of my web access through a Squid cache on the Linux box anyway... A bit annoying, too, that the router's filtering blocks PMTU-discovery packets. Or something on the way does. Maybe it's just accessing it from here?
Finally remembered having had this before, and dropped the MTU of the ethernet card to 1000, and it worked fine. A bit of trial and error suggests the MTU needs to be somewhere around 1460, not 1500. Something to reconfigure on the router when I get home (its telnet interface seems to be borked) but a fun one to sort out; odd that I'd never encountered that one when using the machine from home though. I guess I haven't been uploading large blocks of data. Maybe Windows sets a lower MTU by default? Although I do most of my web access through a Squid cache on the Linux box anyway... A bit annoying, too, that the router's filtering blocks PMTU-discovery packets. Or something on the way does. Maybe it's just accessing it from here?
- Current Mood:
curious - Current Music:Sister Machine Gun - Bitter End [Metropolis]
Comments
Traced it down to an old (high) MTU setting which I'd set to optimise general dial-up usage. Setting it to the normal Windows maximum still didn't work because the VPN protocol adds a few extra bytes of its own, tipping the total packet size over the edge - and apparently wireless protocols will do the same, so you can achieve different maximum MTUs if connecting via wireless or wired connections. I ended up using ping (as described here) to determine the max which my system could support. But I'm sure you knew all that anyway... :-)