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Rick Wagoner

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Rick Wagoner Powered By Docstoc
					Rick Wagoner
IET680 – Final Exam - Lab 06

This lab was focused on routing protocols. Namely is was based on the Routing Information Protocol (RIP) and
how it affects routing traffic and dynamically updates routing information tables when there are topography
changes on the network.

This simulation began by preparing two scenarios. The only difference between the two scenarios was the
insertion of a router node failure in the second scenario. The primary layout of each scenario was essentially
identical. Each layout had four router nodes. The router nodes were interconnected by PPP-DS3 connections
and each router node was connected to two LAN segments by 100BaseT links so we have four router nodes and
eight LAN segments in total. We collected data on RIP traffic sent and received and also on the route table total
number of updates. We then performed a 10 minute simulation on both scenarios to collect the data for
analysis.

The follow charts show the total number of updates for the simulation period for both scenarios on router 1.
There is an initial spike in updates due primarily to the initial creation of the router tables. From a quick
analysis of this chart we can see with no adds or changes to the network there are no need for routing table
updates and the No_Failure chart shows there is no additional activity. However, on the chart were the
connection from Router 1 to Router 2 failed, the Failure scenario, there is additional updates that occurred. The
simulation was configured to instigate the failure at 200 seconds into the simulation or slightly over 3 minutes
as the chart shows. This is an obvious indication that the RIP protocol can dynamically create and update
routing information on-the-fly.




Next we reviewed the routing table from Router 1 from each scenario. Both routing tables are listed below and
we can see from the data in each table that the ‘next hop’ and ‘interface’ have been updated in the Failure
scenario. As an example the the dynamic ability of RIP to update the routing tables we can look at the
destination address of 192.0.8.0. With no failure this destination shows an interface of IF10 and a metric of 1
but with the failure the table gets automatically updated to interface IF11 and a metric of 3.

COMMON ROUTE TABLE snapshot for: No Failure
 Router name: Campus Network.Router1
    at time: 600.00 seconds
ROUTE TABLE contents:
  Dest. Address Subnet Mask          Next Hop Interface Name          Metric     Protocol     Insertion Time
 ------------------ ---------------- ----------- ------------------   --------   ----------   -----------------
 192.0.0.0          255.255.255.0    192.0.0.1   IF0                  0          Direct       0.000
 192.0.1.0          255.255.255.0    192.0.1.1   IF1                  0          Direct       0.000
 192.0.2.0          255.255.255.0    192.0.2.1   IF10                 0          Direct       0.000
 192.0.3.0          255.255.255.0    192.0.3.1   IF11                 0          Direct       0.000
 192.0.4.0          255.255.255.0    192.0.4.1   Loopback             0          Direct       0.000
 192.0.11.0         255.255.255.0    192.0.3.2   IF11                 1          RIP          5.000
 192.0.13.0         255.255.255.0    192.0.3.2   IF11                 1          RIP          5.000
 192.0.14.0         255.255.255.0    192.0.3.2   IF11                 1          RIP          5.000
 192.0.15.0         255.255.255.0    192.0.3.2   IF11                 1          RIP          5.000
 192.0.5.0          255.255.255.0    192.0.2.2   IF10                 1          RIP          5.000
 192.0.6.0          255.255.255.0    192.0.2.2   IF10                 1          RIP          5.000
 192.0.7.0          255.255.255.0    192.0.2.2   IF10                 1          RIP          5.000
 192.0.8.0          255.255.255.0    192.0.2.2   IF10                 1          RIP          5.000
 192.0.9.0          255.255.255.0    192.0.2.2   IF10                 2          RIP          8.855
 192.0.10.0         255.255.255.0    192.0.2.2   IF10                 2          RIP          8.855
 192.0.12.0         255.255.255.0    192.0.2.2   IF10                 2          RIP          8.855

COMMON ROUTE TABLE snapshot for: Failure
  Router name: Campus Network.Router1
    at time: 600.00 seconds
ROUTE TABLE contents:
  Dest. Address Subnet Mask          Next Hop Interface Name          Metric     Protocol     Insertion Time
 ------------------ ---------------- ----------- ------------------   --------   ----------   -----------------
  192.0.0.0         255.255.255.0    192.0.0.1   IF0                  0          Direct       0.000
  192.0.1.0         255.255.255.0    192.0.1.1   IF1                  0          Direct       0.000
  192.0.2.0         255.255.255.0    192.0.2.1   IF10                 0          Direct       0.000
  192.0.3.0         255.255.255.0    192.0.3.1   IF11                 0          Direct       0.000
  192.0.4.0         255.255.255.0    192.0.4.1   Loopback             0          Direct       0.000
  192.0.11.0        255.255.255.0    192.0.3.2   IF11                 1          RIP          5.000
  192.0.13.0        255.255.255.0    192.0.3.2   IF11                 1          RIP          5.000
  192.0.14.0        255.255.255.0    192.0.3.2   IF11                 1          RIP          5.000
  192.0.15.0        255.255.255.0    192.0.3.2   IF11                 1          RIP          5.000
  192.0.5.0         255.255.255.0    192.0.3.2   IF11                 3          RIP          215.000
  192.0.6.0         255.255.255.0    192.0.3.2   IF11                 3          RIP          215.000
  192.0.7.0         255.255.255.0    192.0.3.2   IF11                 2          RIP          215.000
  192.0.8.0         255.255.255.0    192.0.3.2   IF11                 3          RIP          215.000
  192.0.9.0         255.255.255.0    192.0.3.2   IF11                 2          RIP          215.000
  192.0.10.0        255.255.255.0    192.0.3.2   IF11                 2          RIP          215.000
  192.0.12.0        255.255.255.0    192.0.3.2   IF11                 2          RIP          215.000
No we look at the RIP traffic sent charts for both scenarios which are listed below. We can see that in both
scenarios the routers sent RIP advertisements at regular intervals every 30 seconds. Because of the initial
creation of the routing tables we can see additional traffic being sent during the first minute. Looking at the
Failure scenario we can see that there was additional traffic that was sent at approximately the 200 second mark
on the chart. This additional traffic is due to the failure of the link between Router 1 and Router 2 and the
associated updates to recognize and account for this failure.




At this point we added another scenario to our simulation project. We made a duplicate of the Failure scenario
and add a link recovery at 400 seconds into the simulation. In this way we should be able to see the affect of
the link failure and also the link recovery. The following chart makes a comparison of all three scenarios
showing the total number of updates recorded in each. In this chart we can see that the third scenario shows
additional routing table updates for both the failure, at approximately 3 minutes into the simulation, and also the
recover, at approximately 6.5 minutes into the simulation.

After listing the chart including all three scenarios we then list the routing table after completion of the third
simulation run. We can see that this table is different from either of the previous two tables. Going back to our
previous example of the route to the destination address of 192.0.8.0 it now has changed again. It started out
showing the route going to interface IF10 with a metric of one. It then showed a route going to interface IF11
with a metric of 3 after the link failure between router 1 and router 2. Finally, after the link between router 1
and router 2 was restored it showed the table was updated again to show a route going to interface IF10 with a
metric of 1.
COMMON ROUTE TABLE snapshot for: Q3_Recover
  Router name: Campus Network.Router1
    at time: 600.00 seconds
ROUTE TABLE contents:
  Dest. Address Subnet Mask          Next Hop Interface Name          Metric     Protocol     Insertion Time
 ------------------ ---------------- ----------- ------------------   --------   ----------   -----------------
  192.0.0.0         255.255.255.0    192.0.0.1   IF0                  0          Direct       0.000
  192.0.1.0         255.255.255.0    192.0.1.1   IF1                  0          Direct       0.000
  192.0.2.0         255.255.255.0    192.0.2.1   IF10                 0          Direct       0.000
  192.0.3.0         255.255.255.0    192.0.3.1   IF11                 0          Direct       0.000
  192.0.4.0         255.255.255.0    192.0.4.1   Loopback             0          Direct       0.000
  192.0.11.0        255.255.255.0    192.0.3.2   IF11                 1          RIP          5.000
  192.0.13.0        255.255.255.0    192.0.3.2   IF11                 1          RIP          5.000
  192.0.14.0        255.255.255.0    192.0.3.2   IF11                 1          RIP          5.000
  192.0.15.0        255.255.255.0    192.0.3.2   IF11                 1          RIP          5.000
  192.0.9.0         255.255.255.0    192.0.3.2   IF11                 2          RIP          215.000
  192.0.10.0        255.255.255.0    192.0.3.2   IF11                 2          RIP          215.000
  192.0.12.0        255.255.255.0    192.0.3.2   IF11                 2          RIP          215.000
  192.0.5.0         255.255.255.0    192.0.2.2   IF10                 1          RIP          425.000
  192.0.6.0         255.255.255.0    192.0.2.2   IF10                 1          RIP          425.000
  192.0.7.0         255.255.255.0    192.0.2.2   IF10                 1          RIP          425.000
  192.0.8.0         255.255.255.0    192.0.2.2   IF10                 1          RIP          425.000

These simulations give us a very good look at the basic workings of the RIP protocol. This protocol provides a
dynamic mechanism for creating and updating routing information. Through these simulations we could see
how the routing tables were initially created and then there was limited traffic due strictly to route
advertisements. Through forcing a link failure we could see how the routing tables update themselves to
provide alternate routes for the downed connections. We also was able to see how the recovery of a downed
link also initiated routing table updates. This simulation also gave us a good view at how the routing tables are
updated with a new route only when the cost of the route is less. For example, the route to destination address
192.0.9.0 was initially routed to interface IF10 with a metric of 2. When the link between router 1 and router 2
failed the router to this destination was updated to interface IF11 with a metric of 2. The when the link between
router 1 and router 2 was restored the route was not updated because the new route could have been set through
interface IF10 with a metric of 2. Since the metric (or cost) of the route did not benefit by moving back to IF10
this update was not made. This is a mechanism of the protocol to reduce overhead.

Without some form of dynamic route creation and maintenance keeping a network up and running would be a
major job. A single small network would take several more people to maintain than with a dynamic routing
protocol.

				
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