Red Hat Bugzilla – Bug 141055
system-config-network needs to be able to set MTU
Last modified: 2007-11-30 17:10:55 EST
From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5) Gecko/20041107 Firefox/1.0 Description of problem: I'm on a DSL system using PPPoE to encapsulate packets. Unfortunately, this means the effective MTU of the DSL link is 1492 bytes, and not the default ethernet 1500. I need to set my FC3 system's MTU to 1492 if I want to avoid unecessary packet fragmentation for DSL traffic. system-config-network has all kinds of options for editing most Ethernet device configuration options, but there's no way to change the MTU, despite other graphical tools being able to show me that the MTU is set too high. It would be helpful to add an MTU editing option to a future version of system-config-network. Version-Release number of selected component (if applicable): system-config-network-1.3.22-1 How reproducible: Always Steps to Reproduce: 1.Run system-config-network 2.Look for MTU 3.Complain Additional info:
Having investigated this more, I see that the improper MTU for my PPPoE link should result in automatic Path MTU discovery, but I've been seeing symptoms that the MTU is not being set/discovered properly by my FC 3 system, presumably because somewhere along the path the ICMP packets are being blocked. Setting my own MTU in /etc/sysconfig/network-scripts/ifcfg-eth0 seems to have solved connection hangs that I had, all of which speaks to the utility of putting MTU into system-config-network.
Fedora Core 3 is now maintained by the Fedora Legacy project for security updates only. If this problem is a security issue, please reopen and reassign to the Fedora Legacy product. If it is not a security issue and hasn't been resolved in the current FC5 updates or in the FC6 test release, reopen and change the version to match. Thank you!