CCNA Certification Training: Configuring Static Routes On A Cisco Router

The great thing about CCNA certification training is that the skills you learn will truly come in handy when working with Cisco routers and switches in production networks.  That's particularly true of static route configuration.  While most networks use dynamic routing protocols such as RIP, EIGRP, and OSPF to build routing tables, static routes still come in handy sometimes - especially if a routing protocol configuration goes awry. 

Let's say that you just added a new segment to your network and you've successfully added it to your network's routing tables.  Suddenly, on Monday morning, users on that segment can't get to a network resource such as an email server, or they can't get out to the Internet.  We all know what it's like to try to fix something while the phone's ringing like crazy.  That's when we have to do two things.

First, resist the temptation to say “I would fix it, but I’m too busy talking to you”.

Second, use a quick fix to get the issue resolved temporarily while you resolve the issue.

Static routes are a great quick fix.  You can use a static route to get the users where they need to be, which gives you time to find out what the problem is with the dynamic routing protocol. (You must also resist the temptation to apply a static route and declare the problem fixed!)

Static routes are configured with the ip route command, followed by the destination network and mask.  After that, you must specify either the next-hop IP address or the local exit interface.  Both of the following masks are acceptable:

ip route 172.10.1.0 255.255.255.0 210.1.1.1

ip route 172.10.1.0 255.255.255.0 serial0

Using IOS Help on a Cisco router shows the various options:

R1(config)#ip route ?

  A.B.C.D  Destination prefix

  profile  Enable IP routing table profile

  vrf      Configure static route for a VPN Routing/Forwarding instance

R1(config)#ip route 172.10.1.0 ?

  A.B.C.D  Destination prefix mask

R1(config)#ip route 172.10.1.0 255.255.255.0 ?

  A.B.C.D    Forwarding router's address

  BRI        ISDN Basic Rate Interface

  Dialer     Dialer interface

  Loopback   Loopback interface

  Null       Null interface

  Serial     Serial

  TokenRing  IEEE 802.5

Remember, you're specifying either the next-hop router's IP address or the local router's exit interface!

Configuring static routes is a great skill to have in the network room and in the CCNA exam room.  Be ready to configure them in either situation!