VPN Traffic slow

Unanswered Question
Feb 24th, 2010
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Dear Team,

My customer is having 8mb lease line.

The site to site vpn is created between ASA 5520(Near Side) and ASA 5540(Far side).

The mail and other erp applications are running through the tunnel. All the servers are located in far side.

The normal traffic(outside the tunnel) is good. Am able upload and download 17 Mb file within 1 minute.

But the traffic within the tunnel espescially mail traffic is very very slow. To download 8 Mb file, it takes approx. 25 minutes.

Any guidance to solve this issue.

Thanks and regards,


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KARUPPUCHAMY MA... Wed, 02/24/2010 - 06:23
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I am suspecting, that it might be MTU issue.In IPSec tunnel, firewall has to fragment the packets to fit them into the tunnel.because of this, the sending and recieving traffic will be slow.

The easiest way to find out would be to adjust the MTU of  ur mail server and see if that makes any difference or check your tunnel MTU size and your mail server MTU size.




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