On Fri, 30 Mar 2007, James Slepicka wrote: > >>There is no need to touch 'vlan MTU' in the vlan config mode to support > Jumbo frames. > I've always wondered about this. If this isn't required for jumbo frame > support, what is its purpose? > It has been a legacy since the original Cat5k days where vlan mtu was needed for supporting TokenRing CRFs etc.. We probably never cleaned it up. sukumar > Sukumar Subburayan wrote: > > Global System MTU can be used for dropping packets on the > egress. > > For eg, if the 'system jumbomtu.. ' is set at 5000 byte,s this will > make all switchports with 'mtu 9216' to drop packets above 5000 bytes on > the egress, regardless of the individual port mtu configuration. > > L2/L3 physical Interface MTU (mtu <mtu-size>) is used to enable jumbo > frame support on the physical interfaces for L2 or L3. > > SVI MTU again can be used to enable L3 Jumbo frame support for that > Switch Virtual Interface (SVI). > > There is no need to touch 'vlan MTU' in the vlan config mode to support > Jumbo frames. > > When you enable L3 Jumbo frame support on L3 ports (L3 physical port or > SVI), it automatically adjusts 'ip mtu..' . The reverse is not true. > > I don't know about MPLS MTU stuff. Someone else can chime in. > > How you want to use all this depends on what you want to do. > > > sukumar > > On Fri, 30 Mar 2007, [EMAIL PROTECTED] wrote: > > > > Thank you. > > Would you indicate good documentation public available that explains if > when using system MTU it is still necessary use interface MTU? > (or not) > > And shows the relation between: > Vlan MTU > System MTU > MPLS MTU > Interface MTU > > I read documents I found in Cisco page, and applied it on 7600. The > result I got is that only system MTU was not enough. It was necessary > configure interface MTU. > > > Regards, > Alaerte > > -----Original Message----- > From: ext Sukumar Subburayan [mailto:[EMAIL PROTECTED] > Sent: Friday, March 30, 2007 3:27 PM > To: Vidali Alaerte (Nokia-NET/RioDeJaneiro) > Cc: [email protected] > Subject: Re: [c-nsp] Show system jumbomtu > > We had supported 'show system mtu' cli only on the cat4k. > > On the 6k, since the configured system MTU can be viewed in the running > config, it command to show the value was not added. > > we never got to implement 'show system jumbomtu'. > > Please refer to CSCdy28580 > > sukumar > > > > > On Fri, 30 Mar 2007, [EMAIL PROTECTED] wrote: > > > > Do you know if there is any hidden issue with this command? > > I tried it in 2 IOS versions it was supposed to work, but no support. > > Version 12.2(33)SRA1 > > OSR-1#show system ? > % Unrecognized command > OSR-1#show system > > Version 12.2(17d)SXB7 > OSR-2#sh system? > % Unrecognized command > OSR-2#sh system > > > > Tks, > Alaerte > > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ > > > > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ > > > > _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
