On Wed, May 28, 2008 at 1:24 AM, Leon Kofman <[EMAIL PROTECTED]> wrote: > I have a strange issue with Solaris 10 u4. > > When I set jumbo packets on e1000g adapters to MTU 8168 i can not > mount another NFS server that's on the same VLAN, and physical > switch. I can mount other servers from different VLANS, and I > verified that the NFS server that I am trying to mount is not an > issue. I can mount it from anywhere on the network.
Generally speaking, all (non-router) devices need to be configured for the same MTU - there is no way for devices to negotiate the frame size on the same subnet. Setting direct routes using the -mtu modifier may be a way to lower the MTU for exceptional hosts that cannot raise their MTU. When you go to a different subnet different MTU's can work because: - The router can fragment the packet. That is, the router can turn one 8 KB packet into 6 packets of somewhat less than 1.5 KB and pass them on to the destination. - Path mtu discovery kicks in. Solaris will try to figure out what the largest packet size and send packets of that size. See http://www.netheaven.com/pmtu.html for details. In addition to having all devices on the subnet having the same MTU, each switch port on the subnet needs to be configured for jumbo frames as well. -- Mike Gerdts http://mgerdts.blogspot.com/ _______________________________________________ networking-discuss mailing list [email protected]
