ATM Configuration and Troubleshooting Guide

Troubleshooting
Troubleshooting MPOA
Chapter 9 255
Start. Before you start this flowchart, do the following:
Step 1. If practical, kill all other traffic running through both the local and
destination systems’ adapters before you begin.
Step 2. Gather all the necessary routing information of your network.
A Check the ELAN interface status. MPOA uses the services of LAN
Emulation (LANE) Version 2. Before investigating any problem with
MPOA, you should firstmake sure each LAN Emulation interface’s setup
is correct and working. If each one is, you should be able to communicate
with any target located on the same ELAN as your MPOA-capable LAN
Emulation interface, including the local gateway (that is, the router). To
check this, run ping from the local MPOA-capable LEC to any target on
the local ELAN.
If you suspect a problem at this level, go over the steps in
“Troubleshooting LAN Emulation” on page 226.
B Check communication with destination system. Run ping from
the local MPOA-capable LEC to the actual destination system you are
trying to reach via MPOA, to see if you can communicate with it. If you
cannot ping the destination system, you should check the routing
configuration. If you can ping the destination, but MPOA is still not
functional, you should check the MPOA VCs.
C Check the routing configuration. Using MPOA means you are trying
to reach a destination system that is part of an IP subnet none of the
host interfaces (legacy-LAN, CIP, LAN Emulation, etc.) belong to.
To ensure the MPOA-capable LAN Emulation interface is going to be
selected as the “path” to the distant host, you must have configured at
least one static route to that destination. The route command lets you
do this. You can create either a network-based route or a host-based
route to the destination, depending on your needs and your network
topology.
Shown below are the two route commands that were issued on host51
and host178, respectively, to create network static routes:
host51:/> route add net 35.61.185.0 netmask 255.255.255.0 25.61.185.22 1
host178:/> route add net 25.62.185.0 netmask 255.255.255.0 35.61.185.22 1