Why does EIGRP not use delegated router?

I read OSPF introduces a role of designated router in a multi-access network. It's for efficiency of communications. I got it. However, it seems like EIGRP faces a similar situation? Then why does EIGRP not have designated router?

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Comments

networker050184

The term is designated router. The way OSPF operates is different than EIGRP. OSPF routers need to synchronize their databases and build their map of the network off of that. EIGRP routers on the other hand only pass best routes so there is not as much protocol information to share therefore you wouldn't be saving any information with a designated router type role in EIGRP.

DANMOH009

lol i just started google-ing delegated router then! I was well concerned i'd not covered it!!

johnifanx98

networker050184 wrote: »

The term is designated router. The way OSPF operates is different than EIGRP. OSPF routers need to synchronize their databases and build their map of the network off of that. EIGRP routers on the other hand only pass best routes so there is not as much protocol information to share therefore you wouldn't be saving any information with a designated router type role in EIGRP.

Hah. Apologies for the typo first. Since eigrp and ospf are both quiet protocols, should hello packet be the major traffic? If so, it seems eigrp also needs to improve on this...

networker050184

Hello packets are multicast in these situations so hello traffic is not reduced by the DR (designated router) in OSPF or EIGRP if it had such an implimentation. All routers continue to maintain neighbor relationships anyway. They just do not proceed to the point of database synchronization.

johnifanx98

networker050184 wrote: »

Hello packets are multicast in these situations so hello traffic is not reduced by the DR (designated router) in OSPF or EIGRP if it had such an implimentation. All routers continue to maintain neighbor relationships anyway. They just do not proceed to the point of database synchronization.

With DR elected, the number of hello packets is reduced since a non-DR router only needs to send hello to DR

Zartanasaurus

This would be true on a NBMA network only.

johnifanx98

How about broadcast?

networker050184

Nope, doesn't decrease hello traffic in a broadcast domain. As I said earlier all routers still maintain neighbor relationships and exchange hello packets. The neighbor relationship stops at the 2way status and do not exchange database information.

johnifanx98

I'm noted... But does this mean a multi-access network interface would implicitly maintain another internal table for 2-way "neighbors" other than the neighbor table?

networker050184

No, they are kept in the same neighbor table. Labbing this up and debugging or using wireshark would really help you understand.