The SR OS supports multi-chassis redundancy to WPP. This can be achieved by doing following:
Create a loopback interface on both 7750 SRs with the same IP address X.
Use the track-srrp parameter while configuring address X to track the corresponding SRRP instance.
Configure a portal with the same name and same service-id on both nodes to send WPP packets to the destination address.
Use an route-policy to export X to the routing protocol. The metric the route X can be set is based on the specified SRRP state (master or non-master) so that the active node can advertise route X with a better metric. Then the WPP packet from the portal is attracted to the active node.
Only the active node process WPP packet, however in case of standby node receives (such as routing is still re-converging) the WPP packet, then the standby shunts the WPP back to the active node (SRRP master state).
WPP hosts are synced by MCS.