I am using 12.4.21(MD) on a 3745 router located behind an ASA5505. I can receive inbound calls over a SIP trunk just fine, but when I make outbound calls out of CUCM6.1.2 when the call gets to the 3745 it dies. In troubleshooting with the trunk provider, the problem is related to needing to use the FQDN of the proxy they provide, but when that DNS address is looked up, while an IP is slected and returned, that IP is never inserted into the Call Setup Block and there fore the call just dies. If I set it to an IPV4 address the call does work, but the provider needs the DNS entry provided to properly route on their network. In the attached portion of the debug logs on line 10 you can see it got back the chosen IP address, on lines 30 and 31 are where that IP should be inserted instead of 0.0.0.0, and the destination name is what the provider needs to see. If I use an IPV4 instead of the DNS then that address is poulated in all 3 of those fields.
Has any one else experienced this, and if so, is there a work around or fix?