Selective Forwarding

An ESRP-aware switch floods ESRP PDUs from all ports in an ESRP-aware VLAN. This flooding creates unnecessary network traffic because some ports forward ESRP PDUs to switches that are not running the same ESRP groups. You can select the ports that are appropriate for forwarding ESRP PDUs by configuring selective forwarding on an ESRP-aware VLAN and thus reduce this excess traffic. Configuring selective forwarding creates a port list of only those ports that forward to the ESRP groups that are associated with an ESRP-aware VLAN. This ESRP-aware port list is then used for forwarding ESRP PDUs.

Note

We recommend keeping the default settings unless you have considerable knowledge and experience with ESRP.

To configure selective forwarding, use the following command:

configure esrp domain aware add selective-forward-ports portlist {group group number}

When an ESRP-aware switch receives an ESRP PDU on a domain, the software looks up the group to which the PDU belongs. If the group is found, the ESRP-aware switch processes the PDU then and forwards it according to the group‘s specified aware selective forwarding port list. If no selective forwarding port list is configured, the switch forwards the PDU from all of the ports of the domain‘s master VLAN. If the group is not found, the PDU is forwarded on all ports.

When a user adds one or more ports to the ESRP-aware port list (for example, 5:1 and 6:2) that are not part of the master VLAN, the following message appears:
Warning: Port 5:1, 6:2 not currently a member of master vlan
The ports will still be added to the ESRP-aware port list; however, PDUs will not be forwarded out of those ports until they are added to the master VLAN.
To disable selective forwarding, use the following command:

configure esrp domain aware delete selective-forward-ports all|portlist {group group number}