Default and Static routes

milkdroogy · ‎08-09-2007

I'm confused with those!

if i have R1 and ISP routers, ISP connects to the internet cloud and R1 connects to it(what is connected to R1 is or a lan or another set of routers)

so given this topology - when do i choose static route,default route or static-default route on each one of those routers??

and what does the zeros mean in this command:

>ip route 0.0.0.0 0.0.0.0 207.134.6.1

??

anandramapathy · ‎08-09-2007

0.0.0.0 0.0.0.0 means - matching any packet.

if a packet comes to the ethernet interface of the router, the router checks the routing table to find out what to do with the packet.

packets intended for

0.0.0.0 ( All networks ) 0.0.0.0 ( All subnets )

will be forwarded to the gateway 207.134.6.1 which is the WAN interface of the ISP

sundar.palaniappan · ‎08-09-2007

static route - a route that's manually configured and not learned via a dynamic routing protocol.

default route (0.0.0.0/0) - any destination with any mask. It's also known as gateway of last resort.

static default route - default route that's manually configured.

The router wouldn't use the default route to forward traffic if it has a more specific route to that destination. The default route would be used to forward traffic to any destination for which the router doesn't have a specific route.

A dynamic routing protocol has some advantages which the static route doesn't offer as the name suggests it's dynamic. However, for a simple network that doesn't have multiple points of exit and for someone doesn't want to deal with hassle of enabling a dynamic routing protocol then static route might be a sufficient option.

HTH

Sundar

milkdroogy · ‎08-09-2007

which of the routing protocols are dynamic?

(rip? igrp? etc.)

sundar.palaniappan · ‎08-09-2007

All the routing protocols are dynamic, RIP, IGRP, EIGRP, OSPF, IS-IS and BGP. All but BGP is internally used within an AS and BGP is used for inter-AS routing.

HTH

Sundar

bwgray · ‎08-09-2007

A good way to think of a dynamic protocol is just that - it's dynamic. It will change when something on the network changes, and update itself and other routers accordingly.

A static route remains the same unless you change it.