Symptom

The configured HSRP mac-refresh interval on parent interface doesn't get applied to HSRP MGO follow groups configured on sub-interface and the follow groups still send hellos with the default mac-refresh interval of 60 sec. This can be seen in 'show hsrp detail' command output. Config to apply : interface port-channel20 hsrp mac-refresh 1 <<<<<<<<<< configure mac-refresh on parent interface interface port-channel20.1021 hsrp bfd hsrp version 2 hsrp 10 name HSRP_IPv4_0-1 preempt delay minimum 30 reload 30 priority 105 timers msec 500 40 ip 10.10.21.254 interface port-channel20.1901 hsrp version 2 hsrp 10 follow HSRP_IPv4_0-1 ip 10.19.1.254 3.Displays the HSRP status for follow group 10. N7K-1-B1# sh hsrp brief *:IPv6 group #:group belongs to a bundle P indicates configured to preempt. | Interface Grp Prio P State Active addr Standby addr Group addr Po20.1021 10 105 P Standby 10.10.21.252 local 10.10.21.254 (conf) Po20.1901 10 105 Standby - local 10.19.1.254 (conf) N7K-1-B1# sh hsrp group 10 ipv4 port-channel20.1021 - Group 10 (HSRP-V2) (IPv4) Local state is Standby, priority 105 (Cfged 105), may preempt Forwarding threshold(for vPC), lower: 1 upper: 105 Preemption Delay (Seconds) Reload:30 Minimum:30 Hellotime 500 msec, holdtime 40 sec Next hello sent in 0.013000 sec(s) Virtual IP address is 10.10.21.254 (Cfged) Active router is 10.10.21.252, priority 110 expires in 39.706000 sec(s) BFD enabled on interface Session active Standby router is local Authentication text "cisco" Virtual mac address is aaaa.aaaa.aa10 (Cfged MAC) 4 state changes, last state change 2d22h IP redundancy name is HSRP_IPv4_0-1 (cfgd) port-channel20.1901 - Group 10 (HSRP-V2) (IPv4) Local state is Standby, priority 105 (Cfged 105) Forwarding threshold(for vPC), lower: 1 upper: 105 Hellotime 500 sec, holdtime 40 sec Next hello sent in 19.928000 sec(s) <<<<<<<<< Incorrect mac-refresh value Virtual IP address is 10.19.1.254 (Cfged) Active router is unknown BFD enabled on interface Session in unknown state Standby router is local Authentication text "cisco" Virtual mac address is aaaa.aaaa.aa10 (Cfged MAC) 0 state changes, last state change never S lave to m aster: HSRP_IPv4_0-1

Conditions

The problem comes when mac-refresh on parent interface is applied first followed by HSRP group configuration (MGO) on sub-interfaces. mac-refresh config is not applied to follow groups and HSRP MGO follow groups send hello packets with default mac-refresh 60 sec. The problem does not come when HSRP groups are configured first followed by mac-refresh config on parent interface. On the surface, it is a sequencing issue.

Workaround

Re-configure the mac-refresh command on parent interface once all the HSRP groups are configured.

Further Problem Description