cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
1226
Views
15
Helpful
26
Replies

dhcp issue for phone

jjoseph01
Level 3
Level 3

Im having an issue getting dhcp to work with my ip phones. can someone help and see what I did wrong? Thanks.

ip dhcp excluded-address 10.25.102.1 10.25.102.10

!

ip dhcp pool VOICE

network 10.25.102.0 255.255.255.0

dns-server 10.25.6.10

default-router 10.25.102.1

option 150 ip 10.25.100.10

!

interface FastEthernet0/1

no ip address

duplex auto

speed auto

!

interface FastEthernet0/1/0

switchport voice vlan 102

spanning-tree portfast

!

interface FastEthernet0/1/1

switchport voice vlan 102

spanning-tree portfast

!

interface FastEthernet0/1/2

switchport voice vlan 102

spanning-tree portfast

!

interface FastEthernet0/1/3

switchport voice vlan 102

spanning-tree portfast

!

interface FastEthernet0/1/4

switchport voice vlan 102

spanning-tree portfast

!

interface FastEthernet0/1/5

switchport voice vlan 102

spanning-tree portfast

!

interface FastEthernet0/1/6

switchport voice vlan 102

spanning-tree portfast

!

interface FastEthernet0/1/7

switchport voice vlan 102

spanning-tree portfast

!

interface FastEthernet0/1/8

switchport voice vlan 102

spanning-tree portfast

!

interface Vlan1

ip address 10.25.7.1 255.255.255.0

!

interface Vlan2

no ip address

shutdown

!

interface Vlan102

ip address 10.25.102.1 255.255.255.0

26 Replies 26

metalium2007
Level 3
Level 3

do ip phones get dhcp info...some or all?

they get nothing.

mchandak
Level 7
Level 7

I've seen one issue in the past where phones were unable to pick IP Address from a IOS DHCP Server. The fix for this was to run the command "clear ip dhcp conflict *". If this does not resolve the issue, then let me know the Firmware running on the phones

thanks, will get back with you on it in a few.

tried different phone, still the same. tried your command, still the same.

When you hit Settings and then go Under Network Settings, does the DHCP Server show as 0.0.0.0 or there is nothing listed there ??

Also, does the phone get stuck at Configuring VLAN or Configuring IP

AJAZ NAWAZ
Level 5
Level 5

Attach a pc or laptop to VLAN 102. Configure the port as a normal access port i.e. host port. Try to get DHCP address. If you succeed then your config is fine, and we need to then look into the phones and switchport configuration.

hooked laptop to port, configured for swithcport access vlan 102. release and renew of IP, wont get anything.

also, doesnt show anything under dhcp.

oksiazek
Level 5
Level 5

Hi ,

Your problem is probably due to the fact that the interface vlan 102 is not UP !!!

Try the show interface and you will see it probably . So the Dhcp messages cannot occure .

Do this to correct the situation .

Go into config mode

type :

interface range fa0/1/0 - 7

switchport mode trunk

And normally , your interface vlan 102 will go UP . So now when you will connect an ip Phone , it will take an address in the Voice DHCP ( Voice vlan ).

Let me know if it corrects your problem .

Thanks

Olivier

Another thing you investigate is if DHCP needs to be enabled. Im not sure what IOS you are running ( could you post a sh ver? ) but try this command:

service dhcp

to enable dhcp services.

Hope that helps.

Another few points to consider: if my previous suggestion fails.

In your configuration try:

1. Native vlan - Determine if interface vlan8 is up/up. If not, try shutting down interface vlan1 and removing ip address> check interface vlan8 again on up/up status.

2. If your only running voice services you wont need a trunk configuration. If you have a pc connected through your phone you need to unplug it and plug phone direct in or configure your switchports as trunks for proper tagging.

3. Last question.. what is your default router pointing to?

default-router 10.25.102.1

ok, put all ports as trunk ports. It worked ONCE. I got an ip address, it came up with some mismatch error, and now it wont get an ip address anymore. I tried another phone on another port, didnt get one. I currently have them set to trunk ports, because they do run data across it too. My router as a default route back to the main site. Everything is to go over to the main site first. As far as shutting down the vlan1, we are in a live environment, they might not like their data going down right now.

Do you know what the error was exactly? Is your switch configured in a vtp domain? Check to make sure your vlans are still configured the way you expect them to be.

Sorry, I was assuming vlan1 was not Native vlan which im used to in the environment I am in.

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: