CMIT 265
Name:_____________________________

Use esim.

Start esim (i.e. from a fresh unconfigured internetwork).
This step-by-step scenario will give you insight into routing in an internetwork
(*we will ignore the bugs in the simulator!).
This stuff must be done in these steps, don't do any other configuration.

On Router A, show the running config.  
What is the router's hostname:____________________
What is Ethernet 0's IP address:______________

What does 'show protocols' say about e0:______________________________
What does the first line of output of 'show int e0' say:
_________________________________________________________
What does 'show interfaces' say the BW of e0 is:_________
What does it say the BW of Serial 0 is:____________
Does a serial link have a MAC address:_______
Do 'show ip route' and notice that besides the "codes" key there is nothing.
Go into global config mode and change the hostname to A (so the prompt will be A).
Go into interface config mode of E0, assign it its IP address and
class C mask indicated on the diagram and then bring the interface up.
  Configure E1 and S0 too. Include the 'clockrate 56000' command for S0.

Look at the running config to make sure the three interfaces have the
correct IP addresses and masks, are not shutdown, and the S0 has the
correct clock rate.  If not, go back into the relevant interface
config mode to correct the settings.

What does the first line of output of 'show int e0' say:
_________________________________________________________
e1 and s0 should also be "up and up".
What has been added in 'show ip route':
________________________________________
________________________________________
________________________________________
What "code" are they:______________
Notice the second column is network addresses.  The last column is the interface
to forward a packet out of to get to that network.
The /prefix indicates each of these networks is of what class size:______
These are the (only) networks this router knows about now.

Can A ping its three interfaces:________
What happens if ping 10.10.10.1:_______________________________
  it's an unknown-to-A network.  A has no route to it.  So no pings even left the router.
What happens if ping 201.100.11.2:_______________________________
  A knows where this network is (connected to its S0 interface) so it sent out the pings
  on that link but the other end is down so there was no response to the pings)

Logon to router B.  Configure its interfaces with the specified IP
addresses and masks.  Note that the S1 must NOT have a 'clockrate'.
View the running config to confirm all is correct.
What routes does it have in its routing table:
________________________________________
________________________________________
________________________________________


Back on router A:
Has there been any change to A's routing table:_______
What happens now if ping 201.100.11.2:_______________________________
   A has a route to this network, and that IP is now up and can respond.
What happens if ping 199.6.13.1 (B's S0):_____________________
   A has no route to this network.  A doesn't know it can go out its
   S0 to B and that this IP address is at B.
   All A knows about any networks is what's in its routing table.
What happens if ping 219.17.100.1 (B's E0):_____________________
   same situation.
So, even though A can "get to" B via the 201.100.11.0/24 network
it can't get to the "far sides" of B because it doesn't know anything
about those far sides.  A doesn't know where the 199.6.13.0 and 219.17.100.0
networks are, so any attempt to ping/access them goes nowhere;
A won't send the packet out any interface.
These pings originate at router A (and go nowhere) but the same would apply
to packets that arrived at A destined for those networks: A doesn't
know about those networks and thus drops the packets (maybe sending 
back a Destination Unreachable ICMP message to the origin of the packet).


Activate RIP routing on A.  Go into router config mode ('router rip') and add all
three of A's connected networks ('network W.X.Y.Z')
What's been added to the running config of A about RIP routing protocol:
________________________________________
________________________________________
________________________________________
________________________________________
A will now be advertising these networks to other connected routers
that are also running RIP, telling them it knows how to get to these
networks.  But the only connected router of A (B) is not yet running
RIP, so they won't be talking.
Do 'show ip route'.  There should not be any new routes.

Go back to router B.  
Do 'sh ip route'.  There should NOT be any new routes.
 (*if there are, pretend they aren't there.  this crappy simulator has a bug!
  sometimes you really do get what you pay for.)
  The running config correctly shows that RIP is NOT running.)
Activate B's RIP routing protocol but only for networks 201.100.11.0
(its S1) and 199.6.13.0 (its S0), NOT for its 219.17.100.0 (its E0).
What's been added to the running config of B about RIP routing protocol:
________________________________________
________________________________________
________________________________________
B will periodically tell its neighboring routers (e.g. A) this and
be receiving routing updates from its neighbors (e.g. A) about what
they know.
What's been added to the routing table of B: (*pretend these have just now appeared)
__________________________________________________________
__________________________________________________________
What "code" are they:_______
These are networks B has learned about from the RIP info from A.
E.g. a packet at B needing to go the 205.7.5.0 network will be sent
out B's S1 interface to 201.100.11.1 (A's S0).  
The number after the / in  '[120/1]' is the hop count.  RIP uses the number
of hops as the "metric" for determining optimal routes.
The first number (120) of [120/1] is the code for RIP.

Go back to A.  What's been added to its routing table:
__________________________________________________________
What "code" is it:_______
This is the network A has learned about from the RIP info from B.
To get to this network, what interface will be used and to what
    address:_______________________
What happens if now ping 199.6.13.1 (B's S0):_____________________
   A now has a route to this network.  
What happens if ping 219.17.100.1 (B's E0):_____________________
   still no route to that network.
What happens if now ping 199.6.13.2 (C's S1):_____________________
   A now has a route to this network but that interface is down.  

Go to router C and configure its S1 interface.  Verify it can ping B's
S0 and that B can ping it.
The routing table of C should contain only the directly connected
199.6.13.0 network but the simulator is buggy and might show networks
learned by Rip even though RIP is not running on C! [gnashing teeth sound]
From A, Can A ping C's S1:________  (it shouldn't be able to!)
   A has a route to that network but C doesn't/shouldn't have a route
   back to the 201.100.11.1 interface that A sent the ping out of.


Go to routers C, D, and E and configure their interfaces.  Verify that
they are correct by viewing their running config.  Activate RIP on
them for their connected networks.

What has been added to A's routing table:
________________________________________
________________________________________
________________________________________
How many hops to router E's E0 network:_____
Can A ping E's E0:_____

What networks does router E know about:
________________________________________
________________________________________
________________________________________
________________________________________
________________________________________
________________________________________
________________________________________
________________________________________
How many hops to router A's E0 network:_____
Can E ping A's E0:_____