HI, my customer has got a couple of switches x450a and I need to add a couple of Kemp's LoadMaster in HA configuration in this environment. In the Kemp documentation there are raccomandations for the switches where the appliances are attached to, in manner that the UCARP protocol that they use for the HA functions, works well. These are: Confirm that multicast is allowed on the network. Confirm that IGMP snooping is disabled. Ensure that promiscuous mode and PortFast is enabled At least three free IP addresses are needed to set up a HA pair. Verify if VMAC will work in your environment Has someone experiences with a configuration of extreme switches with Kemp? For IGMP snooping I can disable it on the VLAN where the Kemp appliances are connected. Regarding the portfast the equivalent command in ExtremeXOS in KnowledgeBase say to be: configure stpd ports linktype edge edge-safeguard enable bpdurestrict But regarding promiscuous mode and VMAC which are the best settings? Thanks.