Solved: Re: Changing DHCP SCOPE

imagenatas · ‎09-01-2005

Hello,

I need to make some changes to my IP scheme to compliant with my parent company.

I have a hub and spoke network in relation to voice. I have 2 CCM's at my head office and i must change the ip address of the unity at the branch and change the DHCP scope on the gateway.

Once I change the ip address on the unity, how do i make sure the phones know to point to the new unity for voicemail?

Also once i change the DHCP scope, how do i reset all the phones to grab new ip addresses of the new scope. I think I tackle the unity first and then the scope change. Any commands and words of advice would greatly be appreciated.

TIA

jasyoung · ‎09-01-2005

Unity will take care of itself once you change the address and restart the machine. When it registers with CallManager, the Unity-CM TSP identifies itself to CallManager by the port names you set up, by default something like UnityUM-VI[1,2,3,etc]. CallManager accepts this registration from whatever IP address it might come from. If you were changing the CallManager IP addresses, it would be a little more complicated, but changing just Unity is easy. For a walkthrough with screenshots, check out this URL:

http://www.cisco.com/en/US/products/sw/voicesw/ps2237/products_tech_note09186a0080094a69.shtml

The phones will reset on their own if they get cut off from CallManager, as might be the case if you're taking away the network subnet they're on. If not, you can always reset them from the CallManager admin interface. Go to http[s?]://yourcallmanager/ccmadmin, Device, Phone, find the relevant phones and Reset them. Also, if nothing else, you can always walk up to the phone and unplug it and plug it back in. Or shut off inline power on the switch they're attached to. Resetting phones is not hard.

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thisisshanky · ‎09-01-2005

The two tasks you have are relatively independent. First of all phones dont point to unity server. They point to callmanager and its callmanager who transfers incoming calls (unanswered or busy) to voice mail. So you can change the unity ip address without worrying abt phones. Check this link.

http://www.cisco.com/en/US/products/sw/voicesw/ps2237/products_tech_note09186a0080094a69.shtml

Now, changing DHCP scope, its easy, create the new pool (either on server or Cisco IOS), activate it (if on server) and disable the old pool. Phones keep their addresses cached even if you reset them from Callmanager or from the phone itself. I think you will have to erase the config of the phone and reboot (can be a pain if there are a lot of phones).

May be a power down and power on will help grab the new IP. (plug/unplug the cable)

Sankar Nair
UC Solutions Architect
Pacific Northwest | CDW
CCIE Collaboration #17135 Emeritus

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kthorngr · ‎09-01-2005

The phones don't need to know the IP Address of Unity. CCM will know the IP Address and will setup the calls from the phones to Unity. Once you have changed the Unity IP Address just reboot the server and it will re-register with CCM. It is basic stuff but here is a link that discusses changing the IP Address of Unity.

http://www.cisco.com/en/US/products/sw/voicesw/ps2237/products_tech_note09186a0080094a69.shtml

After you change the DHCP scope of the phones you can reset them through CCMAdmin. You can use something like a Device Pool or Partition to reset many devices at once. just choose something that most or all phones at the remote location are assigned to, usually Device Pool is a good choice.

Kevin

View solution in original post

jasyoung · ‎09-01-2005

Unity will take care of itself once you change the address and restart the machine. When it registers with CallManager, the Unity-CM TSP identifies itself to CallManager by the port names you set up, by default something like UnityUM-VI[1,2,3,etc]. CallManager accepts this registration from whatever IP address it might come from. If you were changing the CallManager IP addresses, it would be a little more complicated, but changing just Unity is easy. For a walkthrough with screenshots, check out this URL:

http://www.cisco.com/en/US/products/sw/voicesw/ps2237/products_tech_note09186a0080094a69.shtml

The phones will reset on their own if they get cut off from CallManager, as might be the case if you're taking away the network subnet they're on. If not, you can always reset them from the CallManager admin interface. Go to http[s?]://yourcallmanager/ccmadmin, Device, Phone, find the relevant phones and Reset them. Also, if nothing else, you can always walk up to the phone and unplug it and plug it back in. Or shut off inline power on the switch they're attached to. Resetting phones is not hard.

thisisshanky · ‎09-01-2005

The two tasks you have are relatively independent. First of all phones dont point to unity server. They point to callmanager and its callmanager who transfers incoming calls (unanswered or busy) to voice mail. So you can change the unity ip address without worrying abt phones. Check this link.

http://www.cisco.com/en/US/products/sw/voicesw/ps2237/products_tech_note09186a0080094a69.shtml

Now, changing DHCP scope, its easy, create the new pool (either on server or Cisco IOS), activate it (if on server) and disable the old pool. Phones keep their addresses cached even if you reset them from Callmanager or from the phone itself. I think you will have to erase the config of the phone and reboot (can be a pain if there are a lot of phones).

May be a power down and power on will help grab the new IP. (plug/unplug the cable)

Sankar Nair
UC Solutions Architect
Pacific Northwest | CDW
CCIE Collaboration #17135 Emeritus

jasyoung · ‎09-01-2005

"Phones keep their addresses cached even if you reset them from Callmanager or from the phone itself. I think you will have to erase the config of the phone and reboot (can be a pain if there are a lot of phones).

May be a power down and power on will help grab the new IP. (plug/unplug the cable)

The phones do cache their last DHCP lease, but they should always try to contact a DHCP server, any DHCP server on their operating VLAN, before using it. The cache is mainly to help the phone get along if the DHCP server has gone missing entirely. This can happen if you have centralized DHCP servers and a remote site gets cut off; the site needs to be able to operate in SRST.

kthorngr · ‎09-01-2005

The phones don't need to know the IP Address of Unity. CCM will know the IP Address and will setup the calls from the phones to Unity. Once you have changed the Unity IP Address just reboot the server and it will re-register with CCM. It is basic stuff but here is a link that discusses changing the IP Address of Unity.

http://www.cisco.com/en/US/products/sw/voicesw/ps2237/products_tech_note09186a0080094a69.shtml

After you change the DHCP scope of the phones you can reset them through CCMAdmin. You can use something like a Device Pool or Partition to reset many devices at once. just choose something that most or all phones at the remote location are assigned to, usually Device Pool is a good choice.

Kevin

imagenatas · ‎09-06-2005

Thanks to you guys for clearing up so much. It made the change much more comfortable for me. I will rate all posts so you guys get your points. Thanks for the prompt reply.