On Wed, May 19, 2010 at 09:43:36AM +0100, Howard Jones wrote: > My question though is: what is L2PT actually doing? My original > assumption was that it was encapsulating these packets in another frame > header, so they would no longer look like STP or CDP or whatever to > intervening devices. That doesn't appear to be the case though, or they > wouldn't get blocked.
The frame is not encapsulated, the destination mac addr is rewritten to 01:00:0c:cd:cd:d0. At the far end of the "tunnel", the original mac is restored. For more info: http://www.cisco.com/en/US/docs/ios/12_0s/feature/guide/l2pt.html http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2ZY/configuration/guide/l2pt.html Note that other vendors support the same behavior; e.g.: https://www.juniper.net/techpubs/software/junos/junos92/swconfig-routing/configuring-layer-2-protocol-tunneling.html --Jeff _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
