Are you sure the gigabit ports aren't just reporting giants as FYI? In other words, they may be forwarding the frames and just letting you know that they are giants. From what I understand, the 6509 should forward jumbo frames, if you configure it as you did, and if you disable channeling and trunking, as you did.
By the way, are you sure your servers are really going to take advantage of the jumbo capability, though? Are your Layer 3 protocols and above smart enough to take advantage of the jumboness of your Layer 2?? Also, what else do you have besides Gig Ethernet? Is a router going to have to fragment these jumbos, thus requiring the recipient to reassemble, and thus reducing performance? You've probably thought about these Qs already, but just in case.... _______________________________ Priscilla Oppenheimer www.troubleshootingnetworks.com www.priscilla.com David Titov wrote: > > Hello all, > > I have 2 win2k servers with 3com 3C996 Gigabit Cards attached > to a cisco 6509 > with a WS-X6408-GBIC 8 port gigabit module. I have turned off > trunking and > channeling on the two ports on my 6509 and I have enabled jumbo > frames which > is supposed to set the mtu size to 9216. They are also in > their own vlan and > the mtu in the vlan is set to 9216 as well. On the 3com cards > themselves, > when I try to raise the mtu above the standard 1500, I get > Giants on my > switch. It is like the 6509 is not really allowing packets > over the 1500 mtu > size even though the jumbo frames are enabled. Any ideas? > Here is the show > port jumbo command which verifies that my 2 ports are enabled > for jumbo > frames. > > 6509> (enable) show port jumbo > Jumbo frames MTU size is 9216 bytes. > Jumbo frames enabled on port(s) 9/2-3. > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=53587&t=53516 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
