Hey, I understand that the command 'passive-interface' will prevent routing updates from being sent on the respective interface (in this case, vlan100).
That means that the network advertised below (126.96.36.199) will be advertised, but only the vlan100 will not send routing updates about it, correct?
ip address 188.8.131.52 255.255.255.128
no clns route-cache
switchport trunk allowed vlan add 100
router ospf 300
network 184.108.40.206 0.0.0.127 area 0.0.0.117
The passive-interface command behaves differently, depending on the protocol being used.
In RIP this command will disable sending updates via a specific interface but will allow listening to incoming updates from other RIP speaking neighbors.
In EIGRP it prevents any Hellos from being sent, and therefore does not allow a neighborship to be established, nor any routes to be learned through that interface.
In OSPF, the passive interface command does the same as in eigrp. It prevents Hellos from being sent and thereby disallows adjacencies from being formed. And if an adjacency does exist and the command is executed, the adjacency will be disolved.
However, the passive-interface command does not prevent LSAs from being passed. This is why OSPF neighbors hanging off of different interfaces on that router will learn of that passive interface's network address. LSAs will still be placed in the local OSPF database and then sent and sourced by that interface. This is true, of course, if you are advertising the network under the OSPF process (ie, running OSPF on that interface). In that case, you should see a type 1 router LSA in the OSPF database for that network.
Your other option would be to redistribute connected, which will be advertised as a type-5 extrenal LSA.