Cisco CCNA (200-301)IP ConnectivityEasy
A network administrator is reviewing the routing table on an IPv6-enabled router and sees the following entry: `S 2001:DB8:100::/48 [1/0] via 2001:DB8:ABCD::1, GigabitEthernet0/0` What does the `S` code at the beginning of this entry signify?
- AThe route is a static route.
- BThe route was learned via OSPF.
- CThe route is a summary route.
- DThe route is directly connected.
Show answer & explanationAnswer & explanation
Correct answer: A. The route is a static route.
In Cisco IOS routing tables, the `S` code always signifies a static route, whether for IPv4 or IPv6. The `Codes` section at the top of the `show ip route` or `show ipv6 route` output confirms this.
Why the other options are wrong
- B. `O` signifies OSPF routes.
- C. Summary routes are typically indicated by the protocol that generated them (e.g., `D EX` for EIGRP external summary, or `O IA` for OSPF inter-area summary, though static routes can also be used for summarization). The `S` specifically means static.
- D. `C` signifies a directly connected route, and `L` signifies a local route (the interface's own IP address).
IPv6 Routing Table Codes
Cisco IOS uses single-letter codes in routing table entries to indicate how a route was learned or its type, similar to IPv4 routing tables.
- `S` for Static route.
- `C` for Connected route.
- `L` for Local route (interface's own address).
- `O` for OSPF route.
- Consistency between IPv4 and IPv6 codes for common types.
Memory trick: Codes tell the story, of route's origin and glory.