Hi,
We have a vPC pair of Nexus 93180YC-EX access switches, which have a 4 x 10Gbase-SR-S vPC uplink to a Catalyst 6500 VSS pair core switch. The Nexus access switches are running NXO S7.0(3)I4(6), Catalyst 6500 is running IOS 15.1(2)SY16 and Nexus core switches are running NXOS 9.3.10.
We are going to replace the Catalyst 6500 core switch with new Nexus 93180YC-FX core switches and the new uplinks from the access switches shall be 4 x SFP-H25GB-AOC10M vPC uplink to the Nexus core switches.
What is the best method for migrating the uplinks of the Nexus access switches, that produces the least downtime?
- Gradually replace one of the 10Gbase-SR-S uplinks to the old Catalyst 6500 core switch with a SFP-H25GB-AOC10M uplink to the new Nexus core switch. According to virtual port-channel logic the Nexus access switches should shutdown vPC because of interface speed mismatch until all four cables have been replaced. I'm not sure if it will shut down all interfaces or only those of the secondary vPC switch.
- Create a new 4 x SFP-H25GB-AOC10M vPC uplink to the Nexus core switches in shutdown state. Then activate vPC to the Nexus core switches and immediately shutdown the vPC to the Catalyst core switches. Spanning-tree should then prevent a loop.
Thanks in advance for hints.
Best regards,
Bernd
