Red Hat Bugzilla – Bug 8920
Can't set interface MTU with ifconfig
Last modified: 2008-05-01 11:37:54 EDT
Trying to set the MTU value for an interface:
ifconfig eth0 mtu 1400
--causes the following error.
A workaround appears to be:
echo 1 > /proc/sys/net/ipv4/ip_always_defrag
echo 1 > /proc/sys/net/ipv4/ip_no_pmtu_disc
This error occurred after upgrading to 6.1.
I was able to use ifconfig to set the MTU on a different machine (identical
processors and ethernet cards) that had 6.1 installed on it originally.
I can't reproduce this problem on either of my boxen. It may be that your
networking configuration is different on the upgraded system, and a
feature/limitation of the kernel or hardware is preventing you from changing the
*** This bug has been marked as a duplicate of 9129 ***
*** This bug has been marked as a duplicate of 9215 ***