Updating macsec key on two Linux hosts using 'ip macsec' commands
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I'm trying to do a simple task with no luck so far.
I have two linux hosts communicating using macsec interfaces:
Host1:
[Expert@jaguar_macsec-s01-01:0]# ip macsec show
11: Sync: protect on validate strict sc off sa off encrypt on send_sci on end_station off scb off replay off
cipher suite: GCM-AES-128, using ICV length 16
TXSC: 0050569ed33d0001 on SA 0
0: PN 123787, state on, key 00000000000000000000000000000000
RXSC: 0050569e00d00001, state on
0: PN 19308, state on, key 00000000000000000000000000000000
Host 2:
[Expert@jaguar_macsec-s01-02:0]# ip macsec show
11: Sync: protect on validate strict sc off sa off encrypt on send_sci on end_station off scb off replay off
cipher suite: GCM-AES-128, using ICV length 16
TXSC: 0050569e00d00001 on SA 0
0: PN 35356, state on, key 00000000000000000000000000000000
RXSC: 0050569ed33d0001, state on
0: PN 148262, state on, key 00000000000000000000000000000000
In order to change the key, I create a new tx channel and a new rx channel on both ends, then turn off the old ones:
Host 1:
ip macsec add Sync tx sa 1 pn 1 key 01 81818181818181818181818181818181
ip macsec add Sync rx sci 0050569e00d00001 sa 1 pn 1 key 01 81818181818181818181818181818181
ip macsec set Sync tx sa 1 on
ip macsec set Sync rx sci 0050569e00d00001 sa 1 on
ip macsec set Sync tx sa 0 off
ip macsec set Sync rx sci 0050569e00d00001 sa 0 off
[Expert@jaguar_macsec-s01-01:0]# ip macsec show
11: Sync: protect on validate strict sc off sa off encrypt on send_sci on end_station off scb off replay off
cipher suite: GCM-AES-128, using ICV length 16
TXSC: 0050569ed33d0001 on SA 0
0: PN 155609, state off, key 00000000000000000000000000000000
1: PN 1, state on, key 01000000000000000000000000000000
RXSC: 0050569e00d00001, state on
0: PN 39777, state off, key 00000000000000000000000000000000
1: PN 1, state on, key 01000000000000000000000000000000
Host 2:
ip macsec add Sync tx sa 1 pn 1 key 01 81818181818181818181818181818181
ip macsec add Sync rx sci 0050569ed33d0001 sa 1 pn 1 key 01 81818181818181818181818181818181
ip macsec set Sync tx sa 1 on
ip macsec set Sync rx sci 0050569ed33d0001 sa 1 on
ip macsec set Sync tx sa 0 off
ip macsec set Sync rx sci 0050569ed33d0001 sa 0 off
[Expert@jaguar_macsec-s01-02:0]# ip macsec show
11: Sync: protect on validate strict sc off sa off encrypt on send_sci on end_station off scb off replay off
cipher suite: GCM-AES-128, using ICV length 16
TXSC: 0050569e00d00001 on SA 0
0: PN 36370, state off, key 00000000000000000000000000000000
1: PN 1, state on, key 01000000000000000000000000000000
RXSC: 0050569ed33d0001, state on
0: PN 149509, state off, key 00000000000000000000000000000000
1: PN 1, state on, key 01000000000000000000000000000000
As can be seen, even though I turned off the old channels, I still can't get the new ones to work - the PN (packet number) stays at 1, means no packets have been sent or received using these channels.
Deleting the old channels completely didn't help either.
I couldn't find any documentation that explains how this procedure can be done correctly.
Any advice would be greatly appreciated.
Asked by user29990022
(11 rep)
Mar 20, 2025, 10:15 AM