[j-nsp] GRE problems

[laura.mcdonnell at canterbury.ac.uk]

I currently use a GRE tunnel to transit traffic from one site to
another.  However, this tunnel traverses another network which also uses
a GRE tunnel to transport their traffic over their resilient path.
I do know when using our GRE tunnel over the providers native primary
link, there are no problems.  When traffic traverses the resilient link
(GRE over GRE) large packets do not get through.
All routers are setup to use PMTUD and given that the routers are using
the built in tunnel interface I believe setting the TCP MSS value is not
achievable.

Does anyone know a work around to this problem?

Regards,
 
Laura McDonnell
 
Network Analyst
 
Canterbury Christ Church University
North Holmes Road
Canterbury
Kent
CT1 1QU
 
Tel: +44 (0) 1227 782945
Email: laura.mcdonnell at canterbury.ac.uk
http://www.canterbury.ac.uk
http://www.kentman.ac.uk