How to Bridge two VLANs on a Cisco 6509 and eliminate STP issues
Posted on 2012-03-25
I have a pair of application firewalls that are logically inline to two VLANs on a pair of Cisco 6509 switches. The application FW's are doing transparent bridging between the two VLANs, and I need to remove them from the equation to upgrade them (and then post upgrade completion place them back inline). The application firewalls are in active passive mode and each one is connected to a different 6509 also in an active/passive configuration. The app firewalls have three ports involved. A management port that you connect to the appliance through and two bridge ports where each bridge port is configured to a different VLAN placing the appliance logically inline. I proposed the following config to make the two VLANs bridge themselves while minimizing STP bridge loop issues:
bridge 1 protocol vlan-bridge
bridge 1 priority 8192
The last line is what is supposed to minimize possible STP bridge loops according to Cisco online documentation I found. The onsite CCIE says he's not sure this will work, hence my question. I'm asking you all to vette out this problem and either verify my code will work or propose code that will.