1751 and DHCP

Unanswered Question
Sep 19th, 2007
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I'm trying to get a Cisco 1751-v router to assign DHCP addresses to 7940 phones. I can't for the life of me get this to work.


The phones are plugged into a PoIE 3500 Cisco Switch. The router is plugged into port 24 of the switch.


Switch IP: 172.16.3.254

Router sub IP: 172.16.3.1


The switches VLAN1 is configured with the 172.16.3.254.


From the switch I can ping 172.16.3.1 just fine. And vice versa.


On the router I've setup a DHCP pool with the network address 172.16.3.0 255.255.255.0


I turned on DHCP debugging on the router and can see this message:


Jun 21 05:00:27.999: DHCPD: DHCPDISCOVER received from client 0100.1b53.5c7a.d6 on interface FastEthernet0/0.3.

Jun 21 05:00:27.999: DHCPD: subnet [172.16.3.1,172.16.3.254] in address pool AZ is empty.


The MAC there is the single phone I'm testing... so the request is getting to the router but it's saying the pool is empty.


ip dhcp pool AZ

network 172.16.3.0 255.255.255.0

option 150 ip 172.16.3.1

default-router 172.16.3.1


Router#sho ip dhcp pool


Pool AZ :

Utilization mark (high/low) : 100 / 0

Subnet size (first/next) : 0 / 0

Total addresses : 254

Leased addresses : 0

Pending event : none

1 subnet is currently in the pool :

Current index IP address range Leased addresses

0.0.0.0 172.16.3.1 - 172.16.3.254 0


Router#sho ip dhcp server stat

Memory usage 14207

Address pools 1

Database agents 0

Automatic bindings 0

Manual bindings 0

Expired bindings 0

Malformed messages 12

Secure arp entries 0


Message Received

BOOTREQUEST 0

DHCPDISCOVER 139

DHCPREQUEST 0

DHCPDECLINE 0

DHCPRELEASE 0

DHCPINFORM 4


Message Sent

BOOTREPLY 0

DHCPOFFER 0

DHCPACK 0

DHCPNAK 0

Router#

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Richard Burts Wed, 09/19/2007 - 13:34
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Scott


I am not sure whether it would cause this problem but I would suggest that you configure ip dhcp excluded-address for the router address and probably for the switch address as well.


HTH


Rick

snooter Thu, 09/20/2007 - 04:44
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Yea, I thought of that right after I posted this and it didn't help..


Still getting the message of the pool being empty.

Richard Burts Thu, 09/20/2007 - 08:10
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Scott


Can you post the router configuration? (or at least the interface and subinterface configuration)?


HTH


Rick

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