Hi all, thanks for all the replies so far! Patrick Geoffray wrote: > If you use TCP, the kernel will negotiate the Max Segment Size (MSS) at > connect time. So, a device using a larger MTU will safely communicate > with a device with a smaller MTU, as long as there is no switch/router > in the middle that uses an MTU smaller than at both ends. >
I *think* most stuff we use is TCP based, the only exception I can think of are DNS and possibly NTP but there the packets are tiny anyway (usually at least). > Jumbo Frame does violate the Ethernet spec, but the vast majority of > NICs support it and it's surprising to find some that do not in 2009. > If you are only using TCP, you can safely mix MTU, as long as all the > switches support the largest MTU used. If you use other protocols than > TCP, the best solution is probably to buy NICs than support Jumbo Frames > for those machines. Decent GigE NICs run for $25, so it may be a no > brainer. A tad more expensive since we want to perform PXE booting, but yes, it seems I'll put an order out soonish. Right now there are only ~ 10 machines affected by that, so not a great deal. Thanks all for your input Cheers Carsten _______________________________________________ Beowulf mailing list, [email protected] sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
