R0106-HP MSR Router Series Layer 2 - WAN Configuration Guide(V7)

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• Verify that the PVC is successfully created.
Link report error in PPPoA application
Symptom
When PPPoA is used, the link cannot be up.
Solution
See "Link state error in IPoA application."
Ping failure
Symptom
The physical layer of the interfaces and the line protocol are both up, but they cannot ping each other.
Solution
• If IPoA is used, make sure the IP protocol address mapping is configured correctly. If the interfaces
of two routers are connected back-to-back, the local PVC mapped to the remote IP address must
have the same VPI/VCI value as the remote PVC mapped to the local IP address.
• If two routers are connected back-to-back, make sure at least one of interfaces uses internal
transmission clock (master). If the routers are connected to the ATM network, the transmission clock
must be set to line clock (slave).
• Verify that the ATM interfaces of the two sides are of the same type, for example, multimode fiber
interfaces, single-mode fiber interfaces, or multi-mode 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 use PPPoA, make sure their IP addresses and authentication parameters are correctly
configured.
• If the output from the ping command shows that small packets can pass but big packets cannot,
make sure the MTUs of the two router interfaces are the same and allow big packets to pass.
PVC state is down when ATM interface state is up
Symptom
The state of the ATM interface is up, but the PVC state is down.
Solution
Determine if this fault results from enabling OAM F5 Loopback cell transmission and retransmission
detection or OAM continuity check. When two routers are connected, the VPI/VCI values of the PVCs on
the two routers must be the same. If OAM F5 cell transmission and retransmission detection or OAM
continuity check is enabled, and the VPI/VCI values of the remote node (directly connected to the local
node) is not the same as the local node, the local PVC state cannot change to up.
Ping failure after PPPoA configuration
Symptom
The PVC state is up, but after applications like PPPoA are configured, the remote node cannot be pinged.