1. matches network types or interface types
i.e. physical interface (multipoint) while IP OSPF type is point-to-point
- timers wont match if the interface types are different.
2. Remember that Broadcast & Non-Broadcast try to elect DR/BDR (hub must be the DR)
3. "Broadcast" keyword statement if using frame maps
- not running non-broadcast unicast fashion need a broadcast parameter.
4. Router ID
- read first the LAB if there is requirement for RID same as BGP
router ospf 1
router-id 1.1.1.1 5. DR /BDR
- the higher # the better
first - highest priority
2nd - highest RID
6. DR @ Multipoint FR
- multiple spokes connected to the hub router.
- ensure all host has a direct connectivity to the hub.
note: OSPF packets have TTL of 1, so if you have a "frame-map" statement going from spoke to spoke still will not be able not talk to each other.
CCIE LAB: Frame relay network by default will show up believing that other routers are DR.
a. you can use priority command on the interface @ spoke set priority to 0.
7. Some network interface types requires neighbor command like non-broadcast and point-to-multipoint nonbroadcast. so it is important to look at network type using " show ip ospf interface"
router ospf pid
neighbor {ip} [priority {pri}] [cost {cost}]
note: the cost here are associated to the cost of the link.Problem Areas in Frame Relay
Network Type:
connecting point-to-point/point-to-multipoint to physical interface:
to verify the network type: show ip ospf interface
by default
physical interface network type is non-broadcast with hello/dead 30/120 then must have DR.
on another side of the link (can be the hub) subinterface running in point-to-multipoint will have hello/dead of 30/120 and dont elect DR.
hub (point-to-multipoint)-----------------------(physical)spoke
bye default it will never peer-up
so carefully watch in the ccie lab if you are not allowed to hange the network type of a router.
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