I think static routes get trash talked a lot by those studying for their CCNA exam. Mostly likely because they are just learning about dynamic routing for the first time and find it really fun to set up. And from that moment on static routes get pushed to the back burner and never make it into the router configuration. While static routes may have some disadvantages they also have many advantages that are worth considering.

The Benefits of Static Routes

You have complete control
Quick and easy setup for SMALL networks
Can take priority over dynamic routes
Less overhead CPU usage

Some Disadvantages to Static Routes

If a route goes down another route can’t be automatically discovered
You have to manually configure every route
Can be time consuming

Using Static Routes along side Dynamic Routes

Choosing to use static routes in your network configuration should be an either or choice. You don’t have to use only static routes, and you don’t have to use only dynamic routes. Because the Cisco IOS uses administrative distances you can actually use static routes right along side dynamic routes and whichever route has the lowest administrative distance will get used first.

Static routes by default have an administrative distance of 1. Routes have are directly connected have an administrative distance of 0.

RIP is a dynamic routing protocol that uses hop count for its metric, but it doesn’t take into account the bandwidth of the link. If a route has 3 hops consisting of T1 links and another route with 2 hops consisting of Dial-up connections, RIP will choose the 2 hop route even though the links are slower.

Check out the sample RIP network below. You want to go from Scranton to Utica, but RIP is choosing the slower links. What you can also do is create a static route that will choose the T1 links, but in case one of those links goes down RIP is still running and can route traffic over the dial-up connections.

To set up a static route follow these commands:

ip route <network> <subnetmask> <destination IP/interface>

So for an example to set up a static route on the Scranton Router you would type this command:

ip route 10.10.2.0 255.255.255.0 10.10.3.2
(which is one of the ip addresses on the Nashua router)

What this command means is that it will send any packet from the 10.10.2.0 network and send it to the Nashua router. This is just one simple example in why you might want to set up a static route. The best solution would be to use a better routing protocol like EIGRP.

Default Routes

Another use of static routes is when you are setting up a default gateway. The default gateway usually is where your internet connection is. And so your router will check all available routes in the routing table and if an appropriate route is still not found it can choose to route the packet through the default gateway that you have set up.

For example lets say that the Scranton Router has a route to the Internet through interface serial 0/0. You can set up the default gateway like this:

ip route 0.0.0.0 0.0.0.0 serial 0/0

The default route is also know as the gateway of last resort.

Show The Routing Table

To verify the routes in your routing table you can type this command:

show ip route

Remember that static routes can be great if you have a really small network of lets say only 2 or 3 routers, but anything more then that you should be using a dynamic routing protocol like EIGRP or OSPF.

Static and Dynamic Routes are in important topic for the ICND1, ICND2, or CCNA Exam. Make sure you practice setting up both kinds and know the advantages and disadvantages of each.

Related Topics:

CCNA Study Guide – The fastest way to get Cisco Certified Guaranteed!
Learn to Subnet – The Complete Guide to Mastering How to Subnet
ICND1 Study Guide – Contains everything you need to know to get your CCENT Guaranteed!