Tom Shilson asked:
Just out of curiousity, what is the MTU size?
And Ken responded:
<snip>
.... MTU:57344 ...
<snip>
The reason Tom asked is this item from the April 2004 code drop at:
http://www-128.ibm.com/developerworks/linux/linux390/april2004_restrictions.html#large_mtu_sizes
When using MTU sizes >8K on a network interface, the Linux TCP/IP stack may
run into problems on heavily loaded systems because allocating memory for
packets may fail due to memory fragmentation. As a symptom of this problem
you will see messages of the form "order-N allocation failed" in the system
log; in addition, network connections will drop packets, in extreme cases
to the extent that the network is no longer usable.
As a workaround, use MTU sizes at most of 8K (minus header size), even if
the network hardware allows larger sizes (e.g. HiperSockets, gigabit
ethernet).
Has anyone seen this problem? Has it been fixed? I've been running my
hipersocket (and CTC) interfaces with MTU=32760. Should I start
reconfiguring them all back to 8K? (8184?)
Most of our servers are SLES8, just starting to roll out SLES9.
Mark Wheeler, 3M Company
----------------------------------------------------------------------
For LINUX-390 subscribe / signoff / archive access instructions,
send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit
http://www.marist.edu/htbin/wlvindex?LINUX-390
