RE: VPN & PPPoE

We had to deal with this very issue using IPSEC via Free S/Wan on linux. The solution was to kick the interface (pppoe facing) MTU down to the 1280 range. This was after some experimentation. Play around with the MTU and you should be able to get it to work. If you have a sniffer handy on the client machine, watch to see how much fragmentation is occuring on the interface. Lots of fragmentation seemed to break IPSEC for us.

-----Original Message-----
From: Paul Gaskin [mailto:paul@midwesttechnologies.com] Sent: Friday, January 17, 2003 4:29 PM
To: 'security-basics@securityfocus.com'
Subject: VPN & PPPoE

I am new to the list and I'm not sure if this even falls into this category but I'm getting desperate!

We have set up a VPN and it seems to work fine everyone can log on and move around the network and send and receive email.

One person though... on a DSL using PPPoE can not send e-mail. we have tried everything... has anyone run into this problem?

the user is on a Windows XP laptop connected to a Linksys wireless router (Using PPPoE). and Outlook for E-mail.

Any help would be greatly appreciated

Thanks in advance

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Paul Received on Thu Jan 23 12:59:33 2003