On Tue, Nov 07, 2023 at 10:21:35AM +0100, Daniele B. wrote: > About OpenBSD (7.3 stable) the only thing I need to ask explanation > for is the reason of the error "wrong MTU value" popping up by setting > jumbo frame directly via hostame.mynicdevice; when the setting go > smoothly up via ifconfig manually or by rc.local. Is the nic device > initialization dependent on a sane 1500 MTU value, maybe?
try "ifconfig $device hwfeatures" and look for the "hardmtu" value. On the systems I sampled randomly here, it looks like the em device on this box has "hardmtu 9216" so it should handle jumbo frames just fine. On the other hand the iwx in the laptop over there has "hardmtu 1500", so setting the MTU to anything higher than that would simply fail. it is possible whatever mynicdevice is does not actually support jumbo frames. -- Peter N. M. Hansteen, member of the first RFC 1149 implementation team https://bsdly.blogspot.com/ https://www.bsdly.net/ https://www.nuug.no/ "Remember to set the evil bit on all malicious network traffic" delilah spamd[29949]: 85.152.224.147: disconnected after 42673 seconds.
