Hi All

I have configured GET using MC rekey and it is all working - only thing is
I am not sure how it continues to do so based on what I see and my
knowledge of GET.

The topologies is as so:

R1: GET KS, connected to R1 via P2P Serial, 141.1.123.1
R2: GET GM, connected R1 and R3 via P2Multipoint Serial, 141.1.123.2
R3: GET GM, connected to R2 via P2P Serial, 141.1.123.3

I am using the following ACL for rekeys:

access-list 121 permit udp host 141.1.123.1 eq 848 host 239.0.1.2 eq 848

So basically here is what I am seeing:
- Both R2 and R3 register with R1 fine and receive their initial keys
- Multicast rekey is working with R2 (connected to R1 and R3) as I can see
it receive the rekey in the debugs and its key gets updated
- R3 does not receive the rekey message from R1 that R2 receives and
therefore maintains its original key
- Having placed classification ACLs on the interfaces to monitor GDOI
packets between routers I rarely if ever see unicast rekey messages from R3
to R1 update its key (saw once)
- Pings between the GMs continue to work and be encrypted even after R2 is
rekeyed several times but R3 is not

Now I know a GM will use both its old and new keys for a time range after a
rekey to accommodate other routers that may not yet have updated their keys
but I believe this is for no more than 1 minute and yet the packets between
the GMs continue to be encrypted even though I believe their keys are well
out of sync.

Can anyone enlighten me as to why this is still working considering to the
best of my knowledge it shouldn't be as R2 is being rekeyed yet R3 is not?

Thanks
Ben
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