フリー問題

問題文

A policy for picking OSPF spare paths can also name particular routers to be favored or kept out of a spare path. Which routers may be named that way, and how does the router pick each of them out?

選択肢

1. Only a router next door will do, because the rules are read against the neighbors the port already holds and against nothing further off, and each is picked out by the address of the interface that faces it, and by that alone
2. One next door will do, so will the far end of a spare path raised by the protocol that reserves width, and so will any router the spare calculation walks through, and each is picked out by the identifier the router itself advertises
3. Only a router next door will do, because the rules are read against the neighbors the port already holds and against nothing further off, and each is picked out by the identifier the router itself advertises
4. One next door will do, so will the far end of a spare path raised by the protocol that reserves width, and so will any router the spare calculation walks through, and each is picked out by the address of the interface that faces it, and by that alone