Thursday, August 27, 2020

Extreme Switch - VRRP in dual master state


▶ Case 1 - VRRP dual Master state after state changes on same VRID

• Symptoms
After an VRRP state change a dual VRRP master situations happens

• Cause
This is caused by a bug (CR xos0067506) where some programming of the internal ACL rules needed for VRRP operation are not installed correctly on all ASICs.

• Resolution
Upgrade to one of the following or newer releases where fix is included:
15.3.5.2-patch1-14
16.2.3.5-patch1-1
21.1.3.7-patch1-5

A workaround is to disable VRRP and enable it again, this will re-install the ACL rules on all modules.
Another workaround is causing another single state change that would also trigger this.

disable vrrp vlan-name vrid 1
enable vrrp vlan-name vrid 1


▶ Case 2 - VRRP in dual master state with the same physical IP

• Symptoms
VRRP transitioning to MASTER logs reported on backup node repeatedly.

06/30/2020 05:11:04.25 Slot-1: VLAN VLAN1 vrid 238: transitioning to MASTER(2) 06/30/2020 05:11:03.74 Slot-1: VLAN JAP2_VLAN_Ch vrid 237: transitioning to MASTER(2)
06/30/2020 05:11:03.18 Slot-1: VLAN VLAN1 vrid 240: transitioning to MASTER(2)
06/30/2020 05:15:05.76 Slot-1: VLAN  VLAN1 vrid 237: transitioning to MASTER(2)
06/30/2020 05:15:03.69 Slot-1: VLAN  VLAN1 vrid 240: transitioning to MASTER(2)

• Cause
When VRRP Master/Backup node are configured with the same PHYSICAL IP address for the VLAN , we could observe the VRRP dual master scenario.

• Resolution
Ensure that the physical VLAN IP address on VLAN are not the same on master and backup nodes.


▶ Case 3 - VRRP in dual master state with no tagging on ISC port

• Symptoms
VRRP backup switch is trying to be the MASTER even though the VRRP priority lower than the Switch1.

Switch1 # sho vrrp
                      Virtual                 Master
   VLAN Name VRID Pri IP Address        State MAC Address       TP/TR/TV/P/T    /FR/G/HM
vlan10(En) 0001 200 10.10.10.1     MSTR 00:00:5e:00:01:01  0  0  0 Y 1      N N  N
vlan20(En) 0001 200 10.10.20.1       MSTR 00:00:5e:00:01:01  0  0  0 Y 1      N N  N
vlan30(En) 0001 200 10.10.30.1     MSTR 00:00:5e:00:01:01  0  0  0 Y 1      N N  N
vlan40(En) 0001 200 10.10.40.1         MSTR 00:00:5e:00:01:01  0  0  0 Y 1      N N  N

Switch2 # sho vrrp
                      Virtual                 Master
   VLAN Name VRID Pri IP Address        State MAC Address       TP/TR/TV/P/T    /FR/G/HM
vlan10(En) 0001 100 10.10.10.1     BKUP 00:00:5e:00:01:01  0  0  0 Y 1      N N  N
vlan20(En) 0001 100 10.10.20.1       BKUP 00:00:5e:00:01:01  0  0  0 Y 1      N N  N
vlan30(En) 0001 100 10.10.30.1     MSTR 00:00:5e:00:01:01  0  0  0 Y 1      N N  N
vlan40(En) 0001 100 10.10.40.1         BKUP 00:00:5e:00:01:01  0  0  0 Y 1      N N  N

• Cause
The VLAN30 was not tagged on the Inter-Switch Connection (ISC) port on MLAG.

• Resolution
Please check the ISC port (in this case, it is 47), and tag the missing VLAN on both switches.

show isc
configure vlan vlan30 add ports 47 tagged


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