Date: Tue, 24 Jun 2014 20:43:28 +0200 From: Andrea Venturoli <ml@netfence.it> To: freebsd-net@freebsd.org Subject: MTU not regrowing? Message-ID: <53A9C6D0.3090900@netfence.it>
next in thread | raw e-mail | index | archive | help
Hello. Today I experienced something weird (at least for me) on a 8.4 system: _ the system had vlan3 interface, with default MTU (1500 bytes); _ "ping -D -s 1400 somehost" would work, but "ping -D -s 1500 somehost" would yield "frag needed and DF set" (forgive me if the message is not exact, I don't have it anymore); _ to make some tests I reduced MTU size with "ifconfig vlan3 mtu 500"; _ now, of course, "ping -D -s 400 somehost" would work, but "ping -D -s 500 somehost" would yield "frag needed and DF set"; _ then I raised MTU again with "ifconfig vlan3 mtu 1500" (notice ifconfig would actually report this as "mtu 1500" was shown); _ however the results were as before, i.e. "ping -D -s 400 somehost" would work, but "ping -D -s 500 somehost" would yield "frag needed and DF set"; _ no way I could ping with a packet bigger than 500 bytes until I rebooted. Is this expected behaviour? Any way to get around this? bye & Thanks av.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?53A9C6D0.3090900>