Giga 2.4.3 Spanning Tree

Technical Advisory Bulletin:

TAB-11-0002

Equipment:

TrangoLINK® Giga IDU running fw 2.4.3

Condition:

Spanning Tree Protocol (xSTP) reports a loop on VLAN 1 if more than one connection is made from Giga IDU to switch.

Description:

Software release 2.4.3 enabled the redirection of spanning tree bpdus. If vlan1 is used in production and more than one connection is made from the switch to the Giga IDU or IDUs are cross connected in a repeater or east/west configuration, spanning tree protocol may report a loop exists in the network.

Does not affect GigaPlus or GigaPro product lines.

Solution:

Possible workarounds to this problem involve:

• Only utilize one Ethernet port per Giga IDU.
• Do not use VLAN 1 in your production network.
• Disable spanning tree on links requiring multiple connections to VLAN 1.
• Revert firmware to 2.4.2. The BPDU redirection was the only change in 2.4.3. To revert, check the previous version installed on the IDU. If it matches with 2.4.2 defaults, use the bootimage toggle command and restart. If the previous image is not 2.4.2, follow the upgrade instructions for 2.4.2, but it is not necessary to do the ODU upgrade as no firmware was upgraded on the ODU.