Atm Interface State Error; Pvc State Is Down While Atm Interface State Is Up; Ping Failure After Pppoa Configuration - 3Com MSR 50 Series Configuration Manual

150 C 5: ATM C
HAPTER ONFIGURATION
Check the ATM interfaces of the two sides to make sure that they are of the same
type, for example, both are multimode fiber interfaces or both are single mode
fiber interfaces, or both are multimode fiber interfaces but connected using single
mode. If a multimode fiber interface and a single mode fiber interface are directly
connected, they can communicate in most cases, but sometimes with frequent
packet dropping and CRC errors.
If the two ends are PPPoA, make sure that their IP addresses (should be in the
same network segment) and authentication are correctly configured.
If, according to the ping command, small packets can pass but big packets
cannot, make sure that the mtu configurations of the two router interfaces are
the same.
ATM Interface State Symptom:
Error
The interface state of ATM is DOWN
Solution:
Make sure that the optical fibers are correctly plugged to ATM interface. There
should be two optical fibers, one for receiving information and one for sending
information. The two are not exchangeable. If they are wrongly plugged, the
interface state of ATM cannot be UP.
If two routers are connected back-to-back, check if neither of the two ATM
interfaces enables internal transmission clock. By default, routers use line clock. If
two routers are connected back-to-back, one of them should be configured as
internal transmission lock with the clock master command.
PVC State is Down while Symptom:
ATM Interface State is
The interface state of ATM is UP, but the PVC state is DOWN.
Up
Solution:
Please check if this fault results from enabling OAM F5 Loopback cell transmission
and retransmission detection. When two ATM devices are connected, the VPI/VCI
value of the PVCs on the two devices must be the same. Provided that OAM F5
cell transmission and retransmission detection is enabled, and the VPI/VCI value of
the remote node (connected directly with the local node) is not the same as the
local node, the local PVC state cannot change into UP.
Ping Failure after PPPoA Symptom:
Configuration
The PVC state is UP, but after applications like IPoA are configured, the remote
node cannot be successfully pinged.
Solution:
Make sure that the remote node supports the same application as configured on
the local node. For example, if the local node uses PPPoA, the remote node should
also use PPPoA.
If the remote node supports the same application configured on local node, make
sure that the two sides use the same type of AAL5 encapsulation protocol. For