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Beginner

2003 DHCP issue

Folks,

Everything was working fine, until i moved my DHCP scope from a win 2000 server to a win 2003 server. All the phones that were received a lease from the 2000 server are not having any issues, but the new phones trying to get an ip address for the first time seem to get the default gateway and all the other information (DNS, etc) from the wrong scope???? as a result when they do get an ip address they reject it as it is not in the same subnet as the default gateway??? does someone one why such a thing might be happening???

Here is the router configuration with the helper address

interface GigabitEthernet0/0.1

encapsulation dot1Q 300

ip address 10.10.86.1 255.255.255.0 secondary

ip address 10.10.87.1 255.255.255.0 secondary

ip address 10.63.0.1 255.255.254.0

!

interface GigabitEthernet0/0.2

encapsulation dot1Q 23

ip address 10.60.3.1 255.255.254.0

ip helper-address 10.10.86.10

dress

so when i reset the phone to factor defaults and put in on the network (switchport settings are correct as i use the interface range command and other phones are working).

after sometime i look at network propertes, i see that the phone has receicved all information (default gateway, DNS, etc), but no ip address and DHCP server address information???

not sure where is it getting the default gateway information using DHCP.

any help would be highly appreciated.

Thanks

4 REPLIES 4
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Beginner

an sniffer capture between the phone and the switch when is registering will point you in the right direction. Why is that happening? it could be that the switch is passing the broadcast and since the right DHCP server is not answering (any constraint there??) the old DHCP server gets the msg and answers (not sure why since the giadrr field will not match) anyways the sniffer will give you the answer.. let us know

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Enthusiast

I've seen similar when the new 2003 DHCP server was connected to a catalyst port with trunking enabled/configured as any ip phone port would be. We didn't realize that the NIC and driver supported 802.1q. So basically, the server received two instances of the dhcp request - one on the data vlan via the helper-address and one on the voice vlan via broadcast.

Harcoding "switchport mode access" and "switchport access vlan " did the trick. Let me know.

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Clarification:

Harcoding "switchport mode access" and "switchport access vlan " on the server's catalyst port did the trick. Let me know

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You are the man!

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