Static Routes - Cisco Catalyst 4500 Series Configuration Manual

Chapter 52 Support for IPv6

Static Routes

Networking devices forward packets using route information that is either manually configured or
dynamically learned using a routing protocol. Static routes are manually configured and define an
explicit path between two networking devices. Unlike a dynamic routing protocol, static routes are not
automatically updated and must be manually reconfigured if the network topology changes. The benefits
of using static routes include security and resource efficiency. Static routes use less bandwidth than
dynamic routing protocols and no CPU cycles are used to calculate and communicate routes. The main
disadvantage to using static routes is the lack of automatic reconfiguration if the network topology
changes.
Static routes can be redistributed into dynamic routing protocols but routes generated by dynamic
routing protocols cannot be redistributed into the static routing table. No algorithm exists to prevent the
configuration of routing loops that use static routes.
Static routes are useful for smaller networks with only one path to an outside network and to provide
security for a larger network for certain types of traffic or links to other networks that need more control.
In general, most networks use dynamic routing protocols to communicate between networking devices
but may have one or two static routes configured for special cases.
You can find more information regarding static routes at:
http://www.cisco.com/en/US/docs/ios/ipv6/configuration/guide/ip6-stat_routes.html
First-Hop Redundancy Protocols
IPv6 routing protocols ensure router-to-router resilience and failover. However, in situations in which
the path between a host and the first-hop router fails, or the first-hop router itself fails, First-Hop
Redundancy Protocols (FHRPs) ensure host-to-router resilience and failover.
The Hot Standby Router Protocol (HSRP) protects data traffic in case of a gateway failure.
You can find more information about First-Hop Redundancy Protocols at:
http://www.cisco.com/en/US/docs/ios/ipv6/configuration/guide/ip6-fhrp.html
Unicast Routing
These sections describe the IPv6 unicast routing protocol features supported by the switch:
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RIP
Routing Information Protocol (RIP) for IPv6 is a distance-vector protocol that uses hop count as a
routing metric. It includes support for IPv6 addresses and prefixes and the all-RIP routers multicast
group address FF02::9 as the destination address for RIP update messages.
You can find more about RIP at this location:
OL-25340-01
RIP, page 52-5
OSPF, page 52-6
EIGRP, page 52-6
IS-IS, page 52-6
Multiprotocol BGP, page 52-6
Software Configuration Guide—Release IOS XE 3.3.0SG and IOS 15.1(1)SG
About IPv6
52-5