secondary IP on cucm ?

[mrzh009811]

hi everybody,

is possible to set secondary IP on CUCM ?

because i want to config sip trunk to an ip address on another subnet and without using of NAT on router

[M02@rt37 · Accepted solution]

Hi,

You can't have a secondary address for CUCM. You can not configure this on the CUCM server.

If you have a subcriber on another subnet it should be a solution....

Is it possible to be sharp-cut on what you want exactly to do with your SIP trunk.

And you're right, forget NAT absolutly.

Best Regards.

Ben

[mrzh009811]

Hi Benode371,

as you said we cant have secondary ip on cucm, but i did NAT scenario as this way:

i installed a mikrotik router and configured SrcNAT and DstNat on it, and its now working without problem,

all ports is open and only src ip or dst ip changing on router,

thanks for your help

[M02@rt37]

Ok,

On your mikrotik router, do you have SIP helper activated? Sip helper = sip Alg....

Thanks.

Best Regards.

If this helps, please rate.

Ben

[Dennis Mink]

can you do a nat exemption for the host IP address of your cucm?

sip should work across nat, can be tricky but should work. what FW you got?

[M02@rt37]

Dennis,
"sip should work across nat"...not exactly. NAT is a big probleme for SIP.
NAT is at layer 3, and in Application layer 7 (osi model) we have got in DATA the private ip address....then SIP exchange fail.
Depend of you router generation, we can use SIP Alg protocol and some FW use VIP address....two alternative instead of NAT.

Best Regards

Ben

[mrzh009811]

thanks for your help, i will test it

[Jaime Valencia]

Is there something that blocks/prevents the communication between those two subnets?

[Mohammed al Baqari]

Nope. You can't