09-08-2006 05:28 AM - edited 03-03-2019 04:52 AM
Hi,
we're trying to build a 802.1q-Trunk between a Cisco Catalyst 3550 and an Enterasys Matrix E7 (6H352-25).
The untagged (native: 1) VLAN works but the tagged VLANs don't.
The Cisco Interface (Gi0/1) is configured as usual:
switchport trunk encapsulation dot1q
switchport mode trunk
switchport nonegotiate
It doesn't look like a STP problem.
Does anybody have any experience with that combination or ideas how to make it work?
Thanks in advance
Rolf Fischer
09-14-2006 05:55 AM
When you connect a Cisco switch to a non-Cisco device through an 802.1Q trunk, the Cisco switch combines the spanning tree instance of the native VLAN of the trunk with the spanning tree instance of the non-Cisco 802.1Q switch. However, spanning tree information for each VLAN is maintained by Cisco switches separated by a cloud of non-Cisco 802.1Q switches. The non-Cisco 802.1Q cloud separating the Cisco switches is treated as a single trunk link between the switches. Ensure the native VLAN for an 802.1Q trunk is the same on both ends of the trunk link. If the VLAN on one end of the trunk is different from the VLAN on the other end, spanning tree loops might result. Disabling spanning tree on any VLAN of an 802.1Q trunk can potentially cause spanning tree loops.
09-14-2006 10:31 PM
Another option might be running MST on the 3550, rather than the default PVST mode.
Also, have you researched on the Enterasys end to see if they could support Cisco BPDU format? Nortel Alteon, for example, supports Cisco BPDU format, which enables us to run PVST between Cisco and Alteon.
09-15-2006 12:41 AM
what is the config for the E7 ?
set vlan egress 2 fe.1.1 tagged
set vlan egress 3 fe.1.1 tagged
set vlan egress 4 fe.1.1 tagged
set vlan egress 5 fe.1.1 tagged
set vlan egress 6 fe.1.1 tagged
set vlan egress 7 fe.1.1 tagged
set vlan egress 8 fe.1.1 tagged
set vlan egress 9 fe.1.1 tagged
!
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