22 network under the 2016 workers below the OSPF network is composed of multiple regions, in these routers, belongs to the backbone routers (), belongs to the autonomous system border router (ASBR) is (),



1. A.R 1 B.R 2 C.R 3 D.R 4

2. B.R A.R 3 4 5 D.R C.R 6
The answer is 1 D, 2 D

Explanation: the backbone routers refers to at least one interface defined AS belonging to the main area of the router, any area connected with the trunk of ABR or ASBR will become a backbone routers, AS border router is with the AS external router OSPF routers exchange routing information, the router in the AS internal announcement AS exterior routing information obtained, such AS internal all routers know AS border router routing information, - "only R5, therefore, is the backbone routers



But I look at the wikipedia's explanation is: backbone routers refers to at least one interface is enabled OSPF and backbone Area (Area 0) connected to the router, a backbone routers can also be ABR or ASBR, - "so, R4, R5, R6 are backbone routers,



And then only the ABR is R5?

CodePudding user response:

What, the answer to this question I very lost, if this several options only R1 2, 3, 4, the trunk is R4 can also calculate reluctantly, but R4 and ASBR has anything to do

CodePudding user response:

Good, I was a moderator big 1 2 to make up for a circle, the DD true positive solution

CodePudding user response:

ABR is R4