7937 IP Phone sending excessive DHCP Requests

[Anonymous]

We have a slew of 7937 phones that appear to be sending excessive DHCP requests periodically. From checking their log files we see:

[10-17]00:03:42.600|dhcp |3|00|eventCB: 2
[10-17]00:03:45.630|dhcp |3|00|eventCB: 2
[10-17]00:03:49.660|dhcp |3|00|eventCB: 2
[10-17]00:03:52.700|dhcp |3|00|eventCB: 2
[10-17]00:03:55.730|dhcp |3|00|eventCB: 2
[10-17]00:03:58.760|dhcp |3|00|eventCB: 2

These messages appear every 3 seconds when they occur (as above), and can last for hours at a time intermittently over a few days, then stop. The phones already have a proper IP assigned and are functional to place/receive calls. Intermittently during the flood of DHCP requests, within an hour exactly, or within minutes, we get lease events, which leads to renewing the dhcp lease:

[10-17]00:04:13.910|dhcp |3|00|eventCB: 2
[10-17]00:04:16.940|dhcp |3|00|eventCB: 2
[10-17]00:04:19.980|dhcp |3|00|eventCB: 2
[10-17]00:04:22.010|dhcp |3|00|eventCB: 2

[10-17]00:04:25.040|dhcp |3|00|eventCB: invalid lease
[10-17]00:04:25.041|dhcp |3|00|eventCB: Get a new lease

The DHCP floods can be intermittent, but on average the floods occur roughly every 7 weeks. Current load is 1-4-4 and the lease is set to 8 days.

Even when the flood is not occurring, we see a single DHCP req (eventCB: 2) every 4 days.

These phones are integrated in a Cisco Communication Manager environment. We found a bug for this phone referencing the DHCP floods, which has a workaround of resetting the phones or reducing the DHCP lease to under 7 days. Since these DHCP floods appear most often to occur every 7 WEEKS, we wonder if this is a different defect.

Thanks for any help or suggestions.

[SteffenBaierUK · Accepted solution]

Hello randall,

welcome to the Polycom Community.

Polycom does manufacture these Units for our Partner Cisco and they provide the Software running on these units. Please raise this with Cisco directly or a Cisco community.

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

Polycom Global Services