Why does EIGRP not use delegated router?
johnifanx98
Member Posts: 329
in CCNA & CCENT
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?
Comments
-
networker050184
Mod Posts: 11,962 Mod
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.An expert is a man who has made all the mistakes which can be made. -
DANMOH009
Member Posts: 241
lol i just started google-ing delegated router then! I was well concerned i'd not covered it!!
-
johnifanx98
Member Posts: 329
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
Mod Posts: 11,962 Mod
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.An expert is a man who has made all the mistakes which can be made.
-
johnifanx98
Member Posts: 329
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
Member Posts: 2,008 ■■■■■■■■■□
This would be true on a NBMA network only.Currently reading:
IPSec VPN Design 44%
Mastering VMWare vSphere 5 42.8% -
networker050184
Mod Posts: 11,962 Mod
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.An expert is a man who has made all the mistakes which can be made.
-
johnifanx98
Member Posts: 329
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
Mod Posts: 11,962 Mod
No, they are kept in the same neighbor table. Labbing this up and debugging or using wireshark would really help you understand.An expert is a man who has made all the mistakes which can be made.
