Panasonic NN46240-502 - Manual (Page 55)

3 Ethernet interface configuration
Nortel Secure Router 8000 Series
Configuration - LAN Access and MAN Access
When unshielded twisted pair is used in the Ethernet network, and at least one of the two
connected ends supports 100Base-TX, if the working speeds of the two ends do not match, the
fault can occur.
Troubleshooting procedure
Check that the working speeds of the two Ethernet interfaces are consistent.
3.5.3 Ethernet interfaces discard packets
Fault description
When network traffic increases, the router at one end displays severe network congestion,
while the router at the other end is flooded with error packets. Both routers discard a majority
of packets.
Fault Analysis
A possible cause is that working modes of the routers at the two ends are not consistent.
Troubleshooting procedure
Use the display interface ethernet command to check that the working mode is the same for
the Ethernet interfaces of both routers (either semi-duplex or full-duplex).
3-12 Nortel Networks Inc. Issue 5.3 (30 March 2009)