Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

Phone is unable to get a DHCP address

I resolved a problem for which I had made an earlier posting and wanted to share this with the forum. I had a problem with a small percentage of my IP phones not getting an IP address when using DHCP. New phones would not register but once a phone had been manually configured and had attached properly, I could configure it for DHCP and it would work. There were still a few exceptions to this. I had posted the following snippet from a debug:

DEBUG IP DHCP SERVER PACKET

Jan 17 13:49:58.086: DHCPD: BOOTREQUEST from 0100.06d7.aa8a.06 forwarded to 10.10.125.10.

Jan 17 13:49:58.170: DHCPD: forwarding BOOTREPLY to client 0006.d7aa.8a06.

Jan 17 13:49:58.170: DHCPD: broadcasting BOOTREPLY to client 0006.d7aa.8a06.

Jan 17 13:50:14.087: DHCPD: setting giaddr to 10.10.95.1.

This morning I viewed the output of the SHOW IP INTERFACE command on the local router and I noticed the broadcast address of the VLAN on the trunk was not set to 255.255.255.255. I changed the IP BROADCAST-ADDRESS and all of my problem phones came up. I power-cycled the 3524 switch and all of the IP phones attached promptly.

Hope this helps someone.

1 REPLY
Bronze

Re: Phone is unable to get a DHCP address

Thanks. That’s helpful info!!

93
Views
0
Helpful
1
Replies