Information Technology Reference
In-Depth Information
Its status can be checked via
sh atm pvc 0/36
, as shown previously, or with the earlier command
show
atm vc
.
Medina#
sh atm vc
VCD / Peak Avg/Min Burst
Interface Name VPI VCI Type Encaps SC Kbps Kbps Cells Sts
3/0 1 0 5 PVC SAAL UBR 149760 UP
3/0 2 0 16 PVC ILMI UBR 149760 UP
3/0.1 4 0 36 PVC SNAP VBR 2000 1000 32 UP
Once you located the right VCD number, you can display the VC statistics:
Medina#sh atm vc 4
ATM3/0.1: VCD: 4, VPI: 0, VCI: 36
VBR-NRT, PeakRate: 2000, Average Rate: 1000, Burst Cells: 32
AAL5-LLC/SNAP, etype:0x0, Flags: 0x20, VCmode: 0x0
OAM frequency: 0 second(s)
InARP frequency: 15 minutes(s)
Transmit priority 2
InPkts: 24972, OutPkts: 25137, InBytes: 6778670, OutBytes: 6985152
InPRoc: 24972, OutPRoc: 25419, Broadcasts: 0
InFast: 0, OutFast: 0, InAS: 0, OutAS: 0
InPktDrops: 0, OutPktDrops: 0
CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0
OAM cells received: 0
OAM cells sent: 0
Status: UP
The reader can compare the new
sh atm pvc
command and the old
show atm vc
command. Using the
new command is definitely recommended.
The mapping has been configured as this is a point-to-multipoint interface, and can be checked via:
Medina#
sh atm map
Map list ATM3/0.1pvc4 : PERMANENT
ip 10.2.1.1 maps to VC 4, VPI 0, VCI 36, ATM3/0.1
, broadcast
ip 10.2.1.2 maps to VC 4, VPI 0, VCI 36, ATM3/0.1
, broadcast
The user can see that the subinterface type is multipoint, as such, a mapping was required. In the case of
point-to-point subinterface, the protocol line in the PVC configuration can be skipped since the router
will assume that all IP packets with destination in the same subnet need to be forwarded to the PVC.
Inverse ARP can be configured in the PVC configuration as well to automate the mapping process.
atm pvc
If the user is running 11.3 (non-T train) or earlier, the PVC configuration command is not yet available,
so the old syntax must be used. As you can see, the whole PVC configuration is done in only one line,
seriously limiting the configuration possibilities. (The full description can be found in the command
reference.)
Command Mode
The following section will describe how a basic configuration can be done when the router is running an
IOS software version earlier than 11.3T and mention the most important show commands to be used for
troubleshooting ATM PVCs in a WAN environment.
