If you configure a MAC address limit on VLANs that participate in an ESRP domain, you should add an additional back-to-back link (that has no MAC address limit on these ports) between the ESRP-enabled switches.
Doing so prevents ESRP protocol data units (PDUs) from being dropped due to MAC address limit settings.
MAC Address Limits and VLANs Participating in ESRP is an example of configuring a MAC address limit on a VLAN participating in an ESRP domain.
S2 and S3 are ESRP-enabled switches, while S1 is an ESRP-aware (regular Layer 2) switch. Configuring a MAC address limit on all S1 ports might prevent ESRP communication between S2 and S3. To resolve this, you should add a back-to-back link between S2 and S3. This link is not needed if MAC address limiting is configured only on S2 and S3, but not on S1.