Subject: [ifmib] Question on IP Tunnel MIB

From: Evan Caves <[email-masked]>
Date: Tue, 05 Dec 2000 09:45:37 -0800

A question on the L2TP WG mailing list recently came up about the 
ifStack layering in the L2TP MIB (which relies partially on the 
IP Tunnel MIB) which I am hoping someone here can shed some light
on.

In the IP Tunnel MIB the tunnel interface is layered on top of
the interface stack that is associated with the source IP address
of the tunnel packets. In L2TP's case once the tunnel is up the
source address cannot change (the source address is usually 
determined based on which egress interface is closest to the 
destination tunnel endpoint). However in the event of topology
changes routing can cause tunnel packets to exit the device (or
for that matter enter the device) from a different interface than
that which the source IP address is associated with. If this
occurs wouldn't the layer statistics (and possibly state) between
the ifStack layers (that the IP tunnel is associated with) be 
inconsistant?

evan
-

_______________________________________________
ifmib mailing list
[email-masked]
http://www1.ietf.org/mailman/listinfo/ifmib