When we connect from NE40 to NE16E by ATM622(single mode) interfae, the physical port and line protocol are all up. But we can not ping
from NE40 to NE16E.
1)In NE40 and NE16E , we display atm map-info and find the PVC is up.
2)In NE40 and NE16E , we display atm PVC:
[Alger_est_NE40]disp atm pvc-info interface atm 4/0/0
Interface VCD VPI/VCI Service Enacps PCR SCR MBS Status Name
Atm4/0/0 0 1/10 UBR MUX 599040 - - ACT to_alge~
[Oued_sly_NE16]disp atm pvc-info
VPI/VCI |STATE|PVC-NAME |INDEX |ENCAP|PROT |INTERFACE
1/10 |UP |to_alger_east |1 |SNAP |IP |Atm10/1/0 (UP)
Above the information,we find the encapsulation are different:NE40 is MUX and NE16 is SNAP.After we change the NE40 encapsulation into SNAP,we can ping from NE40 to NE16E.
Because the the physical port and line protocol are all up,so the physical layer is normal.The problem perhaps is from IP layer to ATM layer. So we should check it as following steps:
1)PVC is normal or not.
2) PVC is normal or not
with mapping address.
3)The encapsulation protocol between NE40 and NE16E is same or not.
When you meet problem about interconnection between differrent routers, encapsulation protocol is a key point to check.