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

5. Now let’s try to see how workstation “A” is routed to workstation “B” by using trace
route from the DOS prompt:
C:\WINDOWS\Desktop>tracert 200.150.101.2
Tracing route to STAR10616125 [200.150.101.2]
over a maximum of 30 hops:
1 2 ms 1 ms 1 ms 200.150.100.1
2 25 ms 25 ms 25 ms 201.150.100.2
3 25 ms 25 ms 26 ms 202.150.100.2
4 49 ms 49 ms 50 ms 201.150.101.1
5 60 ms 60 ms 60 ms STAR10616125 [200.150.101.2]
Trace complete.
C:\WINDOWS\Desktop>
The “crucial” step in our trace is in bold above. We can see the path is through the
lower Ethernet path in our diagram. We can actually statically configure the Ethernet
1 interface (on ritchie) to pass the packets through Ethernet 1 by lowering (or raising)
the specific metrics to make the 203.x..x.x. route more desirable. Likewise we could
also raise (or raise) the metrics on Ethernet 0 to make it less desirable.
6. Let’s start by making the 203.x.x.x more desirable by increasing the delay on
Ethernet 0 from 1000 to 10000. Since there is a longer delay on Ethernet 0 (which we
statically set) then the 203.x.x.x network would become the preferred route (with all
other metrics being equal).
ritchie(config)#int e0/0
ritchie(config-if)#delay 10000
7. Now we can repeat our trace and see if it works the way we want (to force the path
over the 203.x.x.x network):
C:\WINDOWS\Desktop>tracert 200.150.101.2
Tracing route to STAR10616125 [200.150.101.2] over a maximum of 30
hops:
1 1 ms 1 ms 1 ms 200.150.100.1
2 68 ms 25 ms 25 ms 201.150.100.2
3 25 ms 26 ms 26 ms 203.150.100.2
4 49 ms 49 ms 49 ms 201.150.101.1
5 59 ms 59 ms 59 ms STAR10616125 [200.150.101.2]
Trace complete.
C:\WINDOWS\Desktop>
8. Bingo! Just what we had hoped for…Let’s check this with Ethereal.
296