Blog2Blog Maak je eigen Blog2Blog | Gratis je eigen blog c.q weblog op internet
CCNA Geheugensteuntje

CCNA Geheugensteuntje

Home - Profile - Archives

Static Routing - Posted at 15:07 on 20/1/2007 by @lfons

Static Routing

 

Static Routing

Static routing is the term used to refer to the manual method used to set up routing. An administrator enters routes into the router using configuration commands. This method has the advatage of being predictable, and simple to set up. It is easy to manage in small networks but does not scale well.

ADVANTAGES

  • Simple to configure
  • Easy to predict and understand in small networks

DISADVANTAGES

  • Requires extensive planning and has a high management overhead
  • Does not dynamically adapt to network topology changes or equipment failures.
  • Does not scale well in large networks.

STATIC ROUTE CONFIGURATION (Cisco)

Default Route

A default route is often called the 'route of last resort'. It is the last route tried when all other routes fail because it has the fewest number of network bits matching and is therefore less specific. A default route is configured on a Cisco router with the following command:

CISCO 'ip route' command:

ip route 0.0.0.0 0.0.0.0 

Static Null Route

A null route routes traffic to a non-existent interface, what is often called a 'bit bucket'. This traffic is effectively dropped as soon as it is received. A null route is useful for removing packets that cannot make it out of the network or to their destination, and decreases congestion caused by packets with no functional destination. During a denial of service attack, a Null route can temporarilly be used near the destination to drop all traffic generated by the attack.

 

 

CISCO 'null route' command:

ip route   null0

Preferred Route

The route which has the greatest number of network bits matching the destination address is the preferred route to a destination. This is referred to as 'longest prefix match'.

CISCO 'null route' command:

ip route 202.148.224.0 255.255.255.128 e0
ip route 202.148.224.128 255.255.255.128 e1

Backup Routes

In cases where redundancy is required, a second route can be placed on another physical path so that if the first route fails, the second route over the less preferred path(s) will be used. By using a second pair of routes. This method can help compensate for network failures.

CISCO router commands:

SPECIFIC ROUTES(used unless down)

ip route 202.148.224.0 255.255.255.128 e0
ip route 202.148.224.128 255.255.255.128 e1
 
BACKUP ROUTES
(used when one of the specifics are down)
ip route 202.148.224.0 255.255.255.0 e0
ip route 202.148.224.0 255.255.255.0 e1

Static Load Balancing

You can create load balancing without using a dynamic routing protocol. Most routers will perform load balancing automatically if several equal cost paths to a destination exist on multiple interfaces. To configure this using static routing, you need only create multiple static routes for more than one interface. This creates more than one equal cost path which will balance the load.

CISCO router commands:

ip route 202.148.224.0 255.255.255.0 e0
ip route 202.148.224.0 255.255.255.0 e1

 


Last Page :: Next Page