Site - to - Site VPN on ADSL connection

Posted on 2008-06-11
Last Modified: 2011-10-19
Hi Expert,

First of all let me admit that i m novice to this technololgy of VPN's & FW's so you may expect all types of silly doubts and questions from my end.

This is in regards to SITE-to-SITE VPN between two offices both on ADSL connection. I was somehow able to fix the VPN between to offices.
It worked for couple of days but later the tunnel went down and it is still down I think when the public IP address changes it is not updated to the hostname registered with DDNS. I have mentioned the configuration in the attached file

Earlier Qlemo suggested me few things to do such as
Clear ike-coo all
enable VPN monitor etc.. It started all working fine but not for very long.

please suggest me if there is anything i am missing for the VPN's to stay stable.

Thanks in advace,

Question by:ssatishh08
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LVL 77

Accepted Solution

Rob Williams earned 500 total points
ID: 21764220
It looks like you are using a DDNS service at both ends. I have never been able to make this work consistently. DDNS at one end works fine but at both ends it seems if the connection is lost even for a second the VPN is not re-established. I have run into this using several different manufacturer's hardware. I think you will find you need a static address at one end for stability.

Author Comment

ID: 21764337
thanks fpr replying Rob but as if now i dont have that option of static Ip address. i have to make it work, a lot depends upon this.... i have to fix it desperately
LVL 77

Expert Comment

by:Rob Williams
ID: 21764449
The point is I am doubtful there is anything you can do to fix it. Best practices for any VPN states that both ends be static. Cisco insists on this. I have about 20 tunnels running that are very stable using DDNS at one end, but have never successfully maintained a connection with 2 DDNS services for more than 2 days. One thing that helps is to ensure any "keep alive" options are enabled.

Perhaps others will have some suggestions though.
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LVL 77

Expert Comment

by:Rob Williams
ID: 21764819
Not to be difficult but as I understand it from the EE guidelines; "Please remember that if the answer to your question is You can't do that you still received an answer."  Step 4 of
My comments were not idle guesses but as my profile perhaps backs up, it is from a reasonable amount of experience.

Author Comment

ID: 21766280
I am not doubting ur capabilities rob its only my desperation and nothing else.
LVL 77

Expert Comment

by:Rob Williams
ID: 21768252
I understand your desperation, but how does closing and refunding points help your problem?

Author Comment

ID: 21772432
i dont waht to close or refund unless i get a solution i got a temp solution which i thougt was full proof so i closed the case earlier

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