Cisco CCNA Certification: Static Routing Tutorial
By Chris Bryant, CCIE #12933
In studying for your CCNA exam and preparing to earn this valuable certification, you may be tempted to spend little time studying static routing and head right for the more exciting dynamic routing protocols like RIP, EIGRP, and OSPF. This is an understandable mistake, but still a mistake. Static routing is not complicated, but it's an important topic on the CCNA exam and a valuable skill for real-world networking.
To create static routes on a Cisco router, you use the ip route command followed by the destination network, network mask, and either the next-hop IP address or the local exit interface. It's vital to keep that last part in mind - you're either configuring the IP address of the downstream router, or the interface on the local router that will serve as the exit interface.
Let's say your local router has a serial0 interface with an IP address of 184.108.40.206/30, and the downstream router that will be the next hop will receive packets on its serial1 interface with an IP address of 220.127.116.11/30. The static route will be for packets destined for the 18.104.22.168 network. Either of the following ip route statements would be correct.
R1(config)#ip route 22.214.171.124 255.255.255.0 126.96.36.199 (next-hop IP address)
R1(config)#ip route 188.8.131.52 255.255.255.0 serial0 (local exit interface)
You can also write a static route that matches only one destination. This is a host route, and has 255.255.255.255 for a mask. If the above static routes should only be used to send packets to 184.108.40.206., the following commands would do the job.
R1(config)#ip route 220.127.116.11 255.255.255.255 18.104.22.168 (next-hop IP address)
R1(config)#ip route 22.214.171.124 255.255.255.255 serial0 (local exit interface)
Finally, a default static route serves as a gateway of last resort. If there are no matches for a destination in the routing table, the default route will be used. Default routes use all zeroes for both the destination and mask, and again a next-hop IP address or local exit interface can be used.
R1(config)#ip route 0.0.0.0 0.0.0.0 126.96.36.199 (next-hop IP address)
R1(config)#ip route 0.0.0.0 0.0.0.0 serial0 (local exit interface)
IP route statements seem simple enough, but the details regarding the next-hop IP address, the local exit interface, default static routes, and the syntax of the command are vital for success on CCNA exam day and in the real world.
About The Author
Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage (www.thebryantadvantage.com), home of free CCNA and CCNP tutorials, The Ultimate CCNA Study Package, and Ultimate CCNP Study Packages.
For a FREE copy of his latest e-books, "How To Pass The CCNA and "How To Pass The CCNP", visit the website and download your free copies. You can now get a FREE CCNA and CCNP exam question sent to your email inbox every day! Get your CCNA certification with The Bryant Advantage!