This article will explain about the macsec flap between the two Ex4600 device

Macsec flapping between Ex4600 without the macsec configuration the interface is stable

• The macsec is running between Ex4600 and Ex4600/4300 VC.
• We noticed the interfaces are flapped between the Ex4600 and Ex4600/4300 VC.
• When we checked the interface extensive output, we could see input errors

Physical interface: xe-x/x/x, Enabled, Physical link is Up

 Input errors:

 Errors: 57923, Drops: 0, Framing errors: 57923, 

• As per the article the issue was resolved post apply the below configuration; however, the issue remains the same.

set securit macsec connectivity-association <name > exclude-protocol lacp

set securit macsec connectivity-association <name > exclude-protocol lldp

• Furthermore, we checked the macsec trace and we could see below logs are generated.

fpc0 PFE_MCSC_OP: ms_gencfg_secy_params_handler: MACsec: xe-x/x/x operation (MACSEC_SC_MSG)

fpc0 ms_gencfg_secy_params_handler: init_done = 1 for ifd xe-x/x/x

fpc0 ms_gencfg_secy_params_handler: macsec_enabled = 1 for ifd xe-x/x/x

fpc0 ms_gencfg_secy_params_handler: macsec_configured = 1 for ifd xe-x/x/x

rshd[23432]: root@re1 as root: cmd='ls -i /var/etc/filters/filter-define.conf'

• The same type of log messages were generated on the device during multiple iterations. According to the logs, it appears that the interfaces have flapped.
• Additionally, we conducted some internal research and discovered a PR that mentions interfaces starting to flap after enabling MACsec.

As per PR below are version having fixed code

20.4R3-S3

21.1R3-S2

21.2R3-S1

21.3R3

21.4R2

21.4R3

PR link: PR1642001