6.20 OSPF MD5 Authentication with Multiple Keys
I have a question to 6.20.
The solution given only authenticates R1-R6 and R4-R6.
However, given that Vlan 146 is a multiaccess-network, shouldn't we also authenticate R1-R4?
This would require an additional md5 key on R1 and R4, e.g.
ip ospf authentication message-digest
ip ospf message-digest-key 16 md5 R1R6KEY
ip ospf message-digest-key 14 md5 R1R4KEY <---