We want to upgrade our pair of Nexus 5548 to the new NX-OS 5.1(3)N2(1a) from the 5.0(3)N1(1c) version. We would like to use the ISSU procedure. But when we execute the command "show spannig-tree issu-impact" we get the following output:
No Active Topology change Found!
Criteria 1 PASSED !!
No Ports with BA Enabled Found!
Criteria 2 PASSED!!
List of all the Non-Edge Ports
Port VLAN Role Sts Tree Type Instance
---------------- ---- ---- --- --------- ---------
Ethernet2/8 1803 Desg FWD PVRST 1803
The 1803 vlan is only used for the peer-keepalive link and it only exists on these two Nexus. So one of the two Nexus needs to be the STP root. That makes the ports on that vlan to be in designated-forwarding state, which is not supported for the ISSU:
sh run int e2/8
!Command: show running-config interface Ethernet2/8
!Time: Fri Jun 8 17:04:33 2012
switchport access vlan 1803
That is the only port that belongs to that VLAN and it is directly connected to the other Nexus 5548. So the only way we see to avoid this port of being in designated-forwarding state is to apply the "no spanning-tree vlan 1803" command. Would it be a problem?
We can imagine that introducing the "spanning-tree port type edge" should not be a good idea, shouldn´t it?
Thank you very much for your help!
Solved! Go to Solution.
one other alternative would be changing the spanning tree root for the vlan to other switch. currently this switch should be the root for vlan 1803 and thats why its showing as Designated Forwarding port. If you do a 'spanning-tree vlan 1803 root primary' or reduce the priority for vlan 1803 on other switch so it becomes the root then the spanning tree issu criteria will succeed on this switch and you can do ISSU. Once ISSU completes on this switch you can repeat the same criteria on other switch
Thak you for help!!
Finally we will try with "no spannig tree 1803" command. We thought about changing the stp root. But the fourth criteria for stp supporting ISSU was that vpc peer should also meet the criteria, as prkrishn said.
Reviewing all the prerequisites for the ISSU, we have seen the following:
Cisco Nexus 5500 Platform switches support Layer 3 functionality. However, the system cannot be upgraded with the ISSU process (non disruptive upgrade) when Layer 3 is enabled. It is required to unconfigure all Layer 3 features to be able to upgrade in a non disruptive way with an ISSU.
We have the interface-vlan feature enabled. But it is only used for two interfaces:
- interface-vlan 510 --> It is only used in order connect to the switch
- interface-vlan 1803 --> The one used for the keepalive
We could administratevely shutdown the interface-vlan 510. But we could not do so with the interface-vlan 1803, since it is used for the keepalive. If we execute "no feature interface-vlan", would the keepalive stop working?
When we execute "sh install all impact ..." command the Nexus does not tell anything about this feature. Is really recommended to disable it? Is it needed for the ISSU procedure?
Thank you very much in advance!!
Yesterday we upgraded the Nexus switches using ISSU and everything went OK. We did not need to disable the interface-vlan feature.
Executing the "no spanning-tree vlan 1803" on the Nexus, everything went OK!
Thank you very much