CME 8.6 - IP source-address

[Craig Herring]

The "ip source-address" in the telephony-service configuration in most common practices use the loopback. Are there different IP addresses that can be use and does the "ip source-address" need to match with any other configuration settings.

[Manish Gogna]

Hi Craig,

It is not mandatory to use only a loopback interface in the ip source-address command. If you check the following link,

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucme/admin/configuration/guide/cmeadm/cmevpn.html

ip source-address ip-address [port port] [any-match | strict-match] 

Identifies the IP address and port number that the Cisco Unified CME router uses for IP phone registration.

•port port—(Optional) TCP/IP port number to use for SCCP. Range is 2000 to 9999. Default is 2000.

•any-match—(Optional) Disables strict IP address checking for registration. This is the default.

•strict-match—(Optional) Instructs the router to reject IP phone registration attempts if the IP server address used by the phone does not exactly match the source address.

HTH

Manish

[Craig Herring]

Manish,

Thanks it was helpful and for the reference link, but does the IP address used need to match any other configuration?

Craig

[Manish Gogna · Accepted solution]

Hi Craig,

It does not need to match any other configuration, just make sure that the interface that is assigned this IP is up.

Manish

[Chris Deren]

Manish is correct (+5), any routable interface on the router will do. If the phone can reach it you can use it.

Chris

[Craig Herring]

Manish/Chris,

Again thanks, maybe you can also clarify another issue. I am trying to understand someone elses configuration. The Call Manager SRST settings are currently configured to use the use the loopbacks of the CMEs. Although on the CMEs it appears that the Loopbacks were not configured to use port 2000. It doesn't appear the loopbacks were used in any of the voice configuration.The IP source-address and the SCCP CCM is configured to use the default router with port 2000. I have my opinion but I would like to hear comments from someone more experienced.

Craig

[Chris Deren · Accepted solution]

Loopbacks don't have to be configured to use any specific ports, it there is no ACL blocking the traffic all ports are open. You can use different interface on sccp dspfarm configuration vs. SRST/CME as long as you point to the correct IP on the CUCM configuration (these are independent configs). I would never do it this way as that does not make it clean and is pointless, but it would work. I would pick one interface and use that interface for all voice configuration.  Loopback is a good solution if you need additional routing redundancy, etc. and rely on routing protocol to route the traffic to the GW with multiple interfaces connected to the switch.

Chris

[Manish Gogna]

I agree with Chris, you can check the "Table 16-1 SRST Reference Configuration Settings" of the following link , specifically the Port and IP address description.

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/8_5_1/ccmcfg/bccm-851-cm/b02srst.html

HTH

Manish

[Craig Herring]

Manish and Chris,

Again thank you.

Craig