The max limit for VRRP sessions is 512 on ACX7100 EVO.
The following syslog is raised if the number of VRRP sessions on ACX7100 EVO exceeds the max limit 512.
*** messages ***
Mar 4 19:00:29 ACX7100 vrrpd[12371]: VRRPD_NEW_MASTER: Interface irb.506 (local address xxx.xxx.xxx.xxx) became VRRP master for group 2 with master reason notMaster
Mar 4 19:00:29 ACX7100 vrrpd[12371]: VRRPD_NEW_MASTER: Interface irb.251 (local address xxx.xxx.xxx.xxx) became VRRP master for group 2 with master reason notMaster
Mar 4 19:00:29 ACX7100 vrrpd[12371]: VRRPD_NEW_MASTER: Interface irb.507 (local address xxx.xxx.xxx.xxx) became VRRP master for group 2 with master reason notMaster
Mar 4 19:00:29 ACX7100 vrrpd[12371]: VRRPD_NEW_MASTER: Interface irb.252 (local address xxx.xxx.xxx.xxx) became VRRP master for group 2 with master reason notMaster
Mar 4 19:00:29 ACX7100 vrrpd[12371]: VRRPD_NEW_MASTER: Interface irb.508 (local address xxx.xxx.xxx.xxx) became VRRP master for group 2 with master reason notMaster
Mar 4 19:00:29 ACX7100 vrrpd[12371]: VRRPD_NEW_MASTER: Interface irb.253 (local address xxx.xxx.xxx.xxx) became VRRP master for group 2 with master reason notMaster
Mar 4 19:00:29 ACX7100 vrrpd[12371]: VRRPD_NEW_MASTER: Interface irb.509 (local address xxx.xxx.xxx.xxx) became VRRP master for group 2 with master reason notMaster
Mar 4 19:00:29 ACX7100 vrrpd[12371]: VRRPD_NEW_MASTER: Interface irb.254 (local address xxx.xxx.xxx.xxx) became VRRP master for group 2 with master reason notMaster
Mar 4 19:00:29 ACX7100 vrrpd[12371]: VRRPD_NEW_MASTER: Interface irb.510 (local address xxx.xxx.xxx.xxx) became VRRP master for group 2 with master reason notMaster
Mar 4 19:00:29 ACX7100 vrrpd[12371]: VRRPD_NEW_MASTER: Interface irb.255 (local address xxx.xxx.xxx.xxx) became VRRP master for group 2 with master reason notMaster
Mar 4 19:00:29 ACX7100 vrrpd[12371]: VRRPD_NEW_MASTER: Interface irb.511 (local address xxx.xxx.xxx.xxx) became VRRP master for group 2 with master reason notMaster
Mar 4 19:00:29 ACX7100 vrrpd[12371]: VRRPD_NEW_MASTER: Interface irb.1 (local address xxx.xxx.xxx.xxx) became VRRP master for group 1 with master reason notMaster
Mar 4 19:00:29 ACX7100 evo-pfemand[8000]: [t:8000] [Error] BrcmPlusMfilter: Maximum number of VRRP sessions exceeded : ifl 9383proto IPv4
Mar 4 19:00:29 ACX7100 evo-pfemand[8000]: [t:8000] [Error] BrcmPlusMfilter: Maximum number of VRRP sessions exceeded : ifl 9089proto IPv4
Mar 4 19:00:29 ACX7100 evo-pfemand[8000]: [t:8000] [Error] BrcmPlusMfilter: Maximum number of VRRP sessions exceeded : ifl 9384proto IPv4
Mar 4 19:00:29 ACX7100 evo-pfemand[8000]: [t:8000] [Error] BrcmPlusMfilter: Maximum number of VRRP sessions exceeded : ifl 9090proto IPv4
Mar 4 19:00:29 ACX7100 evo-pfemand[8000]: [t:8000] [Error] BrcmPlusMfilter: Maximum number of VRRP sessions exceeded : ifl 9589proto IPv4
Mar 4 19:00:29 ACX7100 evo-pfemand[8000]: [t:8000] [Error] BrcmPlusMfilter: Maximum number of VRRP sessions exceeded : ifl 9386proto IPv4
Mar 4 19:00:29 ACX7100 evo-pfemand[8000]: [t:8000] [Error] BrcmPlusMfilter: Maximum number of VRRP sessions exceeded : ifl 9091proto IPv4
Mar 4 19:00:29 ACX7100 evo-pfemand[8000]: [t:8000] [Error] BrcmPlusMfilter: Maximum number of VRRP sessions exceeded : ifl 9424proto IPv4
Mar 4 19:00:29 ACX7100 evo-pfemand[8000]: [t:8000] [Error] BrcmPlusMfilter: Maximum number of VRRP sessions exceeded : ifl 9387proto IPv4
Mar 4 19:00:29 ACX7100 evo-pfemand[8000]: [t:8000] [Error] BrcmPlusMfilter: Maximum number of VRRP sessions exceeded : ifl 9092proto IPv4
Mar 4 19:00:29 ACX7100 evo-pfemand[8000]: [t:8000] [Error] BrcmPlusMfilter: Maximum number of VRRP sessions exceeded : ifl 9491proto IPv4
Mar 4 19:00:29 ACX7100 evo-pfemand[8000]: [t:8000] [Error] BrcmPlusMfilter: Maximum number of VRRP sessions exceeded : ifl 9388proto IPv4
Mar 4 19:00:29 ACX7100 evo-pfemand[8000]: [t:8000] [Error] BrcmPlusMfilter: Maximum number of VRRP sessions exceeded : ifl 9093proto IPv4
Mar 4 19:00:29 ACX7100 evo-pfemand[8000]: [t:8000] [Error] BrcmPlusMfilter: Maximum number of VRRP sessions exceeded : ifl 9357proto IPv4
The max limit for VRRP session is 512 on ACX7100. This is implemented in 21.4R2-EVO, 22.1R1-EVO, 22.1R2-EVO, and 22.2R1-EVO.