-----Original Message----- From: owner-freebsd-...@freebsd.org [mailto:owner-freebsd-...@freebsd.org] On Behalf Of John-Mark Gurney Sent: Thursday, May 31, 2012 11:52 PM To: Bjoern A. Zeeb Cc: freebsd-net@freebsd.org Subject: Re: if_em and large mtu bug?
Bjoern A. Zeeb wrote this message on Wed, May 30, 2012 at 22:26 +0000: > On 30. May 2012, at 11:36 , Eugene Grosbein wrote: > > > 30.05.2012 17:44, Bruce Cran ??????????: > >> Are there any known problems with if_em and jumbo packets? I've found > >> that my ssh connection breaks (when running dmesg etc.) if I configure > >> the mtu to 9216 via rc.conf - but if I initially use a 1500 byte mtu and > >> then manually configure it to 9216 then no problems occur. > >> > > That is due to another known bug; > if you check netstat -rn and the mtu there on your routes you'll figure. > if you remove your addresses/routes and re-add them after changing the mtu, > you'll see it as well. Just to comment, this isn't a bug.. it's that FreeBSD allows you to control the mtu to a host via the routing table... Previously it would always max out the routes MTU meaning that you could never reduce the MTU to a problematic host, while keeping the mtu larger for others i.e. have a mixed network w/ jumbo and normal frames... -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not." This is what I use (I'm JFV's validation engineer): Ifconfig emX <hostname> mtu <mtusize> Doing this adds it to the routing table and seems to avoid any issues. I hope this helps, Jeff _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org" _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"