H3C SR6600 Configuration Manual page 72

serial number is up, line protocol is up
serial number is up, line protocol is down
negotiation failed.
Symptom 3
Configure an IPv6 address on a PPP-encapsulated interface when IPv6 is disabled. The PPP link fails
IPv6CP negotiation and cannot go up. After enabling IPv6, the interface still cannot go up.
Analysis
IPv6CP negotiation cannot succeed when IPv6 is disabled. As IPv6CP does not support re-negotiation,
IPv6CP negotiation cannot succeed even if you enable IPv6 subsequently.
Solution
To resolve the problem, do the following:
Enable IPv6 before configuring an IPv6 address on a PPP link.
If IPv6CP negotiation fails, re-enable the interface with the shutdown command and the undo
shutdown command to re-enable IPv6CP negotiation.
, which indicates that LCP negotiation succeeded.
, which indicates that the interface is active, but LCP
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