With IPHost Network Monitor you can run simple snmp requests against a Avaya device in your network.
ipInterfaceProxyArp
ip Interface Proxy Arp
1.3.6.1.4.1.81.31.1.2.1.7
When proxy ARP is enabled, the router responds to ARP requests received on one link-layer interface for an IP-address that is reachable via another link-layer interface. The response provides the router's own MAC address.
Back to CROUTE-MIB MIB page.
IPHost Network monitor allows you to monitor ipInterfaceProxyArp on Avaya device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Avaya IP phones right now.