7941 will not receive its config thru Ipsec tunnel

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Aug 31st, 2009
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Have 2 ASA's 5520 and 5505 with Ipsec tunnel between. Have Call Manager on "inside" of 5520 and 7941 phone on "Inside of 5505. The 5505 shows phone making a request to CM and the CM responding. Nothing is being filtered or blocked on 5505 side looking at logs. On phone status messages it says unable to resolve CCM2 or CCM1. Workstation is plugged into PC port on phone and can ping internal DNS servers thru tunnel. I have option 150 set in dhcp scope on 5505 in Vlan2 with CM IP's. Also DNS server IP's. Phone get IP from correct scope and is on correct vlan2. It keeps saying registering but never registers. Any Ideas?

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ivarnhagen Mon, 08/31/2009 - 20:51
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the 7941 normally takes a while to register. If you are sure nothing is being blocked by the firewall, and you can ping the CCM from the PC attached to the phone, you can try a factory reset of the phone:


Also check under network settings if you have an alternate TFTP server defined...in that case it would ignore the tftp server it gets from DHCP.

Other than that you could try termporarily permitting all traffic from the phone to the CCM, in case traffic is blocked but not logged.


Nicholas Matthews Tue, 09/01/2009 - 04:24
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Try putting this on the tunnel interface

ip tcp adjust-mss 1300

Sometimes the MSS on IPSEC tunnels is too large.



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