Catalyst 4948 Configurations cause EIGRP problems

[hculver]

I'm configuring a couple of Catalyst 4948 switches to be used as aggregation switches to support server access switch uplinks. Currently, we have 3550 switches we use in the distribution (aggregation) layer but would like to replace them with the Catalyst 4948 switches utilizing HSRP and EIGRP. I've noticed that the 4948 switches behave differenly than the 3550 switches with the global VLAN DOT1Q TAG NATIVE command used in conjuction with the interface switchport trunk native vlan command whereby EIGRP doesn't see the neighboring L3 4948 switch (the 3550's don't have a problem with this configuration). Also, the 4948 HSRP routers don't see each other unlike the 3550's with the global VLAN DOT1Q TAG NATIVE used in conjuction with the interface switchport trunk native vlan command. Has anybody else noticed experienced this?

[beth-martin]

On cat4000 series switch,the command behaves as follows. vlan dot1q tag native . To enable tagging of the native VLAN frames on all 802.1Q trunk ports, use the vlan dot1q tag native command. To disable tagging of native VLAN frames, use the no form of this command. vlan dot1q tag native. By default 802.1Q native VLAN tagging is disabled. When enabled, the native VLAN packets exiting all 802.1Q trunk ports are tagged unless the port is explicitly configured to disable native VLAN tagging. When disabled, the native VLAN packets exiting all 802.1Q trunk ports are not tagged. You can use this command with 802.1Q tunneling. This feature operates on an edge switch of a service-provider network and expands VLAN space by using a VLAN-in-VLAN hierarchy and by tagging the tagged packets. You must use the 802.1Q trunk ports for sending out the packets to the service-provider network. However, the packets going through the core of the service-provider network might also be carried on the 802.1Q trunks. If the native VLANs of an 802.1Q trunk match the native VLAN of a tunneling port on the same switch, the traffic on the native VLAN is not tagged on the sending trunk port. This command ensures that the native VLAN packets on all 802.1Q trunk ports are tagged

This is a different in functionality from 3550 switches