Symptom
Bringing up new links or after a fiber cut. The links get into a unidirectional traffic forwarding condition.ASR9K is able to transmit traffic. But receive packets will be dropped.
Conditions
This is an interoperability issue between ASR 9000 (A9K-8X100-SE/TR or A9K-4X100-SE/TR) and M6 / NCS2K-100G-CK linecard.
This issue is not applicable to PIDs A9K-8X100-L-SE/TR, A9K-2X100G-SE/TR and A9K-1X100-SE/TR.
The issue happens only when link flaps or comes up in DWDM core network or trunk port.
A9K-8X100GE-TR (or A9K-8X100GE-TR) CPAK-100G-SR10 (on ASR card) CPAK-100G-SR10 (on optical card)
NCS2K-200G-CK-LIC (DWDM w/ 20% SD FEC) 600 to 1000 km optical fiber with MSTP amps, ROADMs, etc.
NCS2K-200G-CK-LIC (DWDM w/ 20% SD FEC) CPAK-100G-SR10 (on optical card)
CPAK-100G-SR10 (on ASR card) A9K-8X100GE-TR (or A9K-8X100GE-TR)
Workaround
There is no workaround to prevent this issue. One and only known recovery mechanism is to reload the LC
