MTU Problem on Cisco 7606

Tue Mar 11 06:26:26 UTC 2014

Hi everybody,
I have change my core router from 7206 VXR to 7606 with RSP720 since last 1
month.
I had GRE Tunnel in 7206 with one of my regions with this config:

interface Tunnel1
>  ip mtu 1500
>  ip policy route-map clear-df

I have copy this config to new 7606 with the same config but now I have
Problem with page load.
For example yahoo.com totally does not work.
I change Tunnel interface config to:

interface Tunnel1
>  ip tcp adjust-mss 1360
>  tunnel mode ipip

But again does not make difference, for example yahoo.com solve but put
another site in trouble.
I must notice that my region side router is 7206 VXR and we have not change
that router, It is the same as before was.
The question is what is different between 7600 and 7200 in MTU?
I change "*system jumbomtu*" to *1526* on 7606 but it does not make any
difference.
Would you please help me in this field?
Thanks

IOS on 7606:

c7600rsp72043-adventerprisek9-mz.152-4.S4a.bin

IOS on 7206:
> c7200p-adventerprisek9-mz.124-24.T.bin

-- 
Regards,
Shahab Vahabzadeh, Network Engineer and System Administrator

Cell Phone: +1 (415) 871 0742
PGP Key Fingerprint = 8E34 B335 D702 0CA7 5A81  C2EE 76A2 46C2 5367 BF90