Difference B/W OSPF & EIGRP

1)Ospf is open standard and EIGRP is cisco propreitary.

2)Administrative distance for OSPF is 110 and for EIGRP AD is 100.

3)Ospf uses Cost as the metric values to calculate the shortest path wheres as EIGRP used 5 metric values
(Bandwidth,Delay,Load,MTU & Reliablity) to calculate the shortest path.

4)There is no hop count limitations in the OSPF, there is hop count limitations in EIGRP. I think it supports
maximum of 255 hopcounts in EIGRP.

5)In OSPF, there is no Backup route options, wheres as in EIGRP it will maintain Backup route. So if main link goes down, it will directly take the backup route and starts working, where as in OSPF, if main route fails
it has to recalculate the shortest path.
6)OSPF is a link state routing protocol. EIGRP is a hyprid routing protocol, which is a combination of link state and distance vector.

EIGRP is commonly refered to as an advanced distance vector routing protocol.
7)- EIGRP send incremental updates only when there is a change; it does not send the whole topology or neighbor tables.
OSPF will refresh itself sending Link State Database every 30 minutes.

- Dead timers are different (OSPF 4 x Hello; EIGRP 3 x Hello but 3x is not multiplied)

- both use multicasts addresses to send updates (OSPF 224.0.0.5/6; EIGRP 224.0.0.10)

- EIGRP uses Reliable Transport Protocol (RTP, Cisco proprietary)

- OSPF Frame Relay topologies are still being tested on CCNP (focus on need to config neighbors manually).
- DR on hub and BDR on spokes routers.
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