Before using the ping vc and tracert vc commands to check connectivity of a PW, ensure that the PWE3 network is correctly configured.
VCCV ping can be performed in control word channel mode or Label alert channel mode:
Control word channel: supports detection between UPEs.
Label alert channel: supports detection between CEs and per-hop detection between the UPE and SPE.
By default, VCCV in Label Alert mode is enabled. Before using the control word channel, run the control-word command to enable the control word function. VCCV in control word channel mode is then enabled.
When locating faults on the PW, you can use either VCCV in control word channel mode or normal mode.
Checking connectivity of the PW is not supported in the following situations:
SPEs do not support the ping vc and tracert vc command (these commands are supported only by UPEs).
Multiple users cannot run the command simultaneously. That is, the devices on the two ends cannot ping a VC at the same time. On a device serving as both a UPE and an SPE, if the PW serving as an SPE is performing VCCV ping, the PW serving as a UPE will be unable to perform VCCV ping. That is, two VCCV pings cannot be performed on a same device at the same time.
The MTU check of the VC is not supported.
For an MH-PW, the local VC ID and VC type need to be specified.
In the control word mode, if VC IDs are different, the VC ID of the remote UPE needs to be specified. In the MPLS Label Alert mode, the addresses of the remote peer SPEs or UPEs need to be specified.
Because a static PW does not support signaling negotiation, configurations of the UPE control word on both ends of the PW are different, with the control word being enabled on one end, but disabled on the other. When the MPLS Label Alert mode is enabled on both ends, the PW can be Up and the ping vc command can work. CEs, however, cannot communicate with each other because the control words are different.
Control word channel
ping vc pw-type pw-id [ -c echo-number | -m time-value | -s data-bytes | -t timeout-value | -exp exp-value | -r reply-mode | -v ] * control-word [ remote remote-ip-address peer-pw-id | draft6 ] * [ ttl ttl-value ] [ pipe | uniform ]
To check the connectivity of a PW switching, run the following commands:
ping vc pw-type pw-id [ -c echo-number | -m time-value | -s data-bytes | -t timeout-value | -exp exp-value | -r reply-mode | -v ] * control-word remote remote-ip-address peer-pw-id sender sender-address [ ttl ttl-value ] [ pipe | uniform ]
Label Alert channel
ping vc pw-type pw-id [ -c echo-number | -m time-value | -s data-bytes | -t timeout-value | -exp exp-value | -r reply-mode | -v ] * label-alert [ no-control-word ] [ remote remote-ip-address | draft6 ] * [ pipe | uniform ]
Normal mode
ping vc pw-type pw-id [ -c echo-number | -m time-value | -s data-bytes | -t timeout-value | -exp exp-value | -r reply-mode | -v ] * normal [ no-control-word ] [ remote remote-ip-address peer-pw-id ] [ ttl ttl-value ] [ pipe | uniform ]
Control word channel
tracert vc pw-type pw-id [ -exp exp-value | -f first-ttl | -m max-ttl | -r reply-mode | -t timeout-value ] * control-word [ draft6 ] [ full-lsp-path ] [ pipe | uniform ]
tracert vc pw-type pw-id [ -exp exp-value | -f first-ttl | -m max-ttl | -r reply-mode | -t timeout-value ] * control-word remote remote-ip-address [ ptn-mode | full-lsp-path ] [ pipe | uniform ]
tracert vc pw-type pw-id [ -exp exp-value | -f first-ttl | -m max-ttl | -r reply-mode | -t timeout-value ] * control-word remote remote-pw-id draft6 [ full-lsp-path ] [ pipe | uniform ]
Label Alert channel
tracert vc pw-type pw-id [ -exp exp-value | -f first-ttl | -m max-ttl | -r reply-mode | -t timeout-value ] * label-alert [ no-control-word ] [ remote remote-ip-address ] [ full-lsp-path ] [ draft6 ] [ pipe | uniform ]
Normal mode
tracert vc pw-type pw-id [ -exp exp-value | -f first-ttl | -m max-ttl | -r reply-mode | -t timeout-value ] * normal [ no-control-word ] [ remote remote-ip-address ] [ full-lsp-path ] [ draft6 ] [ pipe | uniform ]