Aastra VOIP phone and ELRP

[Mykhaylo_Skrypk]

Hi All,

We are currently struggling with an issue which appears to exist between our Extreme edge switches and certain models of VoIP phones.

Basically, despite having ELRP configured, if a user creates a loop by plugging both the PC and LAN ports on the back of a phone into the same switch the switch does not detect it.

We have carried out packet captures. With a laptop plugged directly into the switch, we see the ELRP packets every 2 seconds. If we put one of these phones in between (with the laptop plugged into the phones PC port) the ELRP packets do not arrive.

This suggests that the phones are stripping/filtering the packets in some way.

Any suggestions are welcome.

Thank you,
Mykhaylo

[Mykhaylo_Skrypk]

Hi Matthew,

Just to confirm that this configuration works fine with Aastra 6731i model.

Only Aastra 4425 or 4422 are affected.

enable elrp-client
configure elrp-client periodic B37 ports 1:1-46, 2:1-3, 2:5-40, 2:42-48, 3:1-46, 4:1-48, 5:1-5, 5:7-48 interval 2 log-and-trap disable-port duration 30
configure elrp-client periodic B37_VOIP ports 1:1-46, 2:1-3, 2:5-40, 2:42-48, 3:1-46, 4:1-48, 5:1-5, 5:7-48 interval 2 log-and-trap disable-port duration 30

Cheers,
Mykhaylo

[Kevin_Kim]

Storm control (flood rate-limit) would help. ('disable port' option is available in 16.1 or later)

# configure ports rate-limit flood broadcast out-actions disable-port
Execute the command
log Generate log event if traffic exceeds configured rate
trap Generate SNMP trap if traffic exceeds configured rate

[Eric_Burke]

Was going to suggest the same as Matthew. ELRP is associated with one or more VLAN's.

[Matthew_Helm1]

Do you use a separate VLAN for voice and data? if so, do you have the elrp client configured for both VLANs on the port?