Cisco CCNA (200-301)IP ConnectivityMedium
An engineer wants to configure a static IPv6 route to network 2001:db8:100::/64 out of interface GigabitEthernet0/1 using the next-hop link-local address fe80::2. Which command correctly implements this?
- Aipv6 route 2001:db8:100::/64 GigabitEthernet0/1 fe80::2
- Bip route 2001:db8:100::/64 GigabitEthernet0/1 fe80::2
- Cipv6 route 2001:db8:100::/64 fe80::2
- Dipv6 route GigabitEthernet0/1 2001:db8:100::/64 fe80::2
Show answer & explanationAnswer & explanation
Correct answer: A. ipv6 route 2001:db8:100::/64 GigabitEthernet0/1 fe80::2
When using a link-local address as the next hop for an IPv6 static route, the exit interface must also be specified because link-local addresses are not globally routable and are ambiguous without an interface reference.
Why the other options are wrong
- B. The 'ip route' command is for IPv4; IPv6 routes require 'ipv6 route'.
- C. Omitting the exit interface causes an error/failure because link-local next hops require it to resolve scope.
- D. The interface and prefix order are reversed from correct IOS syntax.
IPv6 Static Route with Link-Local Next Hop
An IPv6 static route pointing to a next-hop link-local address must include the exit interface because link-local addresses are not unique across interfaces.
- Syntax: ipv6 route <prefix>/<len> <exit-intf> <link-local-addr>
- Link-local addresses (fe80::/10) are interface-scoped
- Global unicast next hops do not require the exit interface
Memory trick: Link-local needs a map (interface) to know where it lives.