Open Shortest Path First (OSPF)
See also IGP, IS-IS, and RIP.
I want to know why when I configured OSPF process, I usually configure a "default passive" statement. I also configure a "no passive interface" statement on interface which I want OSPF to participate in. However, in order for OSPF to work in the below configuration, I had to remove the default and the no passive statements.
router ospf 300 router-id 10.19.xxx.xxx auto-cost reference-bandwidth 10000 area ### stub no-summary timers throttle spf 10 100 5000 timers lsa arrival 80 network 10.19.xxx.0 0.0.127.255 area ###
I usually configure it as below
router ospf 300 router-id 10.19.xxx.xx auto-cost reference-bandwidth 10000 area ### stub no-summary timers throttle spf 10 100 5000 timers lsa arrival 80
no passive-interface TenGigabitEthernet1/1/1 no passive-interface TenGigabitEthernet1/1/2 network 10.19.xxx.0 0.0.127.255 area ###
I tried it the above way and OSPF adjacencies would not form. ??? This is a cisco C9300-24U switch.
If you want to make router adjacency then no used "no passive-interface" command on that interface in which both routers are connected to each other to make adjacency. By default passive-interface is on in every interface in routers.
you would remove the "no passive-interface" command on those interface in which you want to create neighbor-ship between routers. After that neighbor-ship will up.
Different between passive and no-passive command are:
1) no passive-interface command on interfaces where adjacency are desired.
2) passive-interface default command to make all interfaces passive by default.
I thing i will be help you.