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656 Chapter 9: Scenarios for Final Preparation
12
What debug command options provide IP RIP update details?
13
Imagine that R3's E0 interface needed to use a new IP address and mask (10.1.1.1,
255.255.255.0). If the user was in user mode, what steps would be necessary to change the
IP address?
14
With the user in privileged mode, the user remembers that the IP RIP configuration should
be updated, based on the change in the previous question. List the steps necessary to make
this change.
15
If an EXEC command you cannot recall begins with the letter C, how can you get help to
list all commands that start with C? List the steps; assume that you are in privileged mode.
16
Name the two commands to list the currently used configuration in a router.
17
Name the two commands to list the configuration that will be used the next time the router
is reloaded.
18
What does CDP stand for?
19
Define the metric used by IPX RIP.
20
What does GNS stand for? What role does R2 play in the GNS process? What about R3?
Solutions to Scenario 9-1, Part C--Verification and Questions
The answers to the questions for Scenario 9-1, Part C are as follows:
1
Each bridge and switch sends a CBPDU claiming to be the root. The bridge or switch with
the lowest bridge priority--or, if a tie occurs, the bridge or switch with the lowest value
for root bridge ID--is considered to be the root.
2
Because all port costs are equal, Switch2 will be getting CBPDUs with a lower cost in
E1/0. Likewise, Switch3 will be receiving CBPDUs with a lower cost on its E1/0 port. So,
each switch will consider its E1/0 port to be its root port; this port is placed in a forwarding
state.
3
Switch3 reacts after Switch2's MaxAge time expires and Switch2 stops sending CBPDU
messages onto its E1 (the Ethernet segment that Switch2 and Switch3 have in common).
Switch3 then transitions its E1 port to listening state, then to learning state, and finally to
forwarding state.
4
The debug ip rip command provides the detailed RIP debug output. The debug ip rip
event shows summary information about the same updates. An example of each is shown
in Example 9-4. This example shows four routes being described in the update to R3. One
of the routes (appropriately) missing in the update is 163.1.13.128, which is the subnet on
the serial link between R1 and R3. The other (appropriately) missing route is the route to
163.1.3.128--thus, R1's best route to that subnet is through R3. Split-horizon rules
prevent either route from being advertised.
ch09.fm Page 656 Monday, March 20, 2000 5:23 PM