For ELRP to detect loops on a protocol-based VLAN (other than the protocol any), you need to add the ethertype 0x00bb to the protocol.
create vlan v1 create vlan v2
configure vlan v1 protocol IP configure vlan v2 protocol decnet
configure vlan v1 add ports 1 configure vlan v2 add ports 2
enable elrp-client configure elrp-client periodic v1 ports all interval 5 seconds log configure elrp-client periodic v2 ports all interval 5 seconds log
configure protocol IP add snap 0x00bb configure protocol decnet add snap 0x00bb
VLANs v1 and v2 can now detect the loop on their respective broadcast domains.