Learning by Doing: CISCO Certified Network ... - SCN Research

Now let’s explore some of the other options for static routes:
optik(config)#ip route 1.0.0.0 255.0.0.0 serial0/1 ?
Distance metric for this route
A.B.C.D Forwarding router's address
name Specify name of the next hop
permanent permanent route
tag Set tag for this route
The first option we see a distance metric for this route. Each routing protocol has
a different default distance metric assigned to it. RIP has a default static route
distance of 120. So actually we already put that in our command, even though it
does not appear in our ip route command. What this is used for is when we want
to put in more than one static route on our router. The router will automatically
select the static route with the lowest distance metric first then, if that route is not
available, go to the route with the second lowest distance metric and then so on.
Distance metrics, as you can see, vary from 1 to 255. Here are some common
metrics for you to know about here at this time:
Connected interface 0
Static route 1
RIP 120
Unknown 255
If we were to add another router in then we would need to add in another static
route. Using that methodology if we had a network with many routers we could
bury ourselves in static routes which has the possibility of causing major
problems. In our example we just did instead of setting a static route between the
two routers we could set a default network route on optik. This will essentially
allow us to add routers at will without all those static routes. Setting many static
routes essentially defeats the purposes of having routers make decisions anyways.
So there. In the next couple of labs you will learn more about different types of
routes and their uses. In the meantime let’s try to do some more exercises and
learn by doing!
9. Ok. Let’s try putting a loop back into our network. Connect another serial line
from s0/1 (DTE) on phiber to s0/0 (DCE) on optik. Use 56000 for the clockrate.
We know from our routing loop labs that our split-horizon is set by default to
prevent routing loops, but if we have two paths wouldn’t we want to take
advantage of that? Absolutely! If all of our metrics are equal, then our routers
will perform load-balancing across the equal lines. Now, of course, you know we
can change that. The command to change load-balancing is “variance.” Use your
knowledge of the CISCO technical support site and router help features to find
out more about this command and how to use it. What we are more concerned
with in this lab is static routing. Set your new serial connection to have a
different administrative distance than the main line so it will act as a backup line.
10. Ping and trace the route between workstation A and B.
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