Question

A network administrator is adding acls to a new ipv6 multirouter environment. Which ipv6 ace is automatically added implicitly at the end of an acl so that two adjacent routers can discover each other

Answer 1

Answer:

permit icmp any any nd-na. Traditional IPv4 ACLs are generally depicted as a sequence of permit statements that may have an implicit deny clause as the last line.

Although an implicitly deny is also there in IOS IPv6 ACLs, there are some other facts that one must know.

(1) There are other permit statements that are designed to allow two of the main Neighbor Discovery (ND) messages that handles Neighbor Advertisement messages and permit icmp any any nd-ns.

(2) If your environment needs Router Solicitation (RS) and Router Advertisement (RA) messages to be allowed then these lines will have to be configured explicitily as we do in the case of regular permits.

(3) If you add an explicit deny as in the last line of a V6 ACL, then the statement will take over the implicit permits as has been described earlier in the case of nd-na and nd-ns.

Explanation: