Had a requirement from a customer to add in a static ARP address for a Exchange 2010 Cas Array (Multicast NLB) I had put in.
A bit (read:lot) of digging got me to the following;
set interfaces vlan.100 family inet address 10.1.254.254/16 arp 10.1.31.6 multicast-mac 03:bf:0a:01:1f:06</DIV< div>
Where vlan.100 is the vlan ID, family inet address the “Default Gateway” for that VLAN, 10.1.31.6 is the NLB address and 03:bf:0a… is the MAC address of the NLB.
You can find this by opening the NLB configuration tool and selecting properties on any node, and selecting “Cluster Parameters” 🙂