The ttl-copymode command specifies a TTL propagation mode for multi-segment PW detection in an NQA PWE3 ping test instance.
The undo ttl-copymode command deletes the TTL propagation mode configured in the NQA view.
By default, the TTL propagation mode configured using the mpls ldp ttl-mode command is used.
Usage Scenario
When you monitor a multi-segment PW, you can run the ttl-copymode command to control the TTL values in labels.
The system differently processes TTL values in either pipe or uniform propagation mode.If you set the propagation mode to pipe, the system removes the outer label, decreases the TTL value in the inner label by 1, and sets the TTL value in the outer label to 255 after receiving a packet.If you set the propagation mode to uniform, the system copies the TTL value in the outer label to the inner label, decreases the TTL value in the inner label by 1, and sets the TTL value in the outer label to the TTL value in the inner label after receiving a packet.Precautions
If parameters need to be changed during the running of the test instance, the system prompts you whether to terminate the test instance. Press "Y" or "N" as required.