To prioritize traffic between the
WestCoast router and the EastCoast router, using priority queuing.
Scenario:
Our company has given us the task of
connecting our east coast office with the west coast office via
ISDN. It has been determined that we need to have a strict queuing
policy for traffic going across this link. Certain traffic should
have a higher priority than other traffic. We have decided that all
TCP traffic should have high priority, ICMP traffic should have
medium priority, all UDP traffic should have low priority, and all
other traffic should have normal priority. It is our responsibility
to connect these two routers together and configure priority queuing
correctly.
Lab Tasks:
Cable the lab as shown in the
diagram.
The first router to be configured
is the WestCoast router. Log into the router and enter global
configuration mode.
Configure the following basic
information into the WestCoast router:
Configure
the hostname WestCoast on the router.
Configure
the router to prevent the lookup of misspelled words.
Configure
IGRP routing with the AS# 777. Ensure that no routing updates
will be sent out of interface BRI 0.
What is the command to prevent
routing updates?
Configure
the enable password to be cisco.
Configure
the Ethernet 0 interface with the IP address 10.100.100.1/24.
The next step is to configure the
ISDN BRI connection on the WestCoast router from the global
configuration:
Configure the ISDN switch type to
be National ISDN-1.
Configure the username and
password of the router to be dialed, the username should be
EastCoast, and the password should be cisco.
What is the command to set the
username and password?
Configure the dialer list to
permit IP traffic.
Since the routers are not sharing
routing tables, we need to configure a static route to the
EastCoast router. The IP address of the EastCoast network is
10.30.30.0/24 and the IP address to the router is
10.200.200.2/24.
We are going to be using dialer
profiles in this lab, so the final part of the basic configuration
of the WestCoast router is to configure the BRI interface and dialer
interface.
Configure
the BRI interface with the IP address 10.200.200.1/24.
Configure
the Service Profile Identifiers: SPID1=51055512340001,
SPID2=51055512350001
Configure
the encapsulation type to be PPP.
For
security reasons, configure the authentication to be CHAP.
To
keep the line from staying connected all of the time,
configure the idle timeout to be 60 seconds.
Apply
the dialer list to the interface
At what router prompt should you
enter the idle timeout command?
Lastly, the router needs to know
where to dial. Configure the dialer map with the IP address of
the EastCoast router(10.200.200.2), the name of the router to be
dialed(EastCoast), and the number to dial(5558000).
Next, Configure the following
basic information into the EastCoast router:
Configure
the hostname EastCoast on the router.
Configure
the router to prevent the lookup of misspelled words.
Configure
IGRP routing with the AS# 777. Ensure that no routing updates
will be sent out of interface BRI 0.
Configure
the enable password to be cisco.
Configure
the Ethernet 0 interface with the IP address 10.30.30.1/24.
The next step is to configure the
ISDN BRI connection on the EastCoast router from the global
configuration:
Configure the ISDN switch type to
be National ISDN-1.
Configure the username and
password of the router to be dialed, the username should be
WestCoast, and the password should be cisco.
Configure the dialer list to
permit IP traffic.
What is the dialer list command to
permit IP traffic?
Since the routers are not sharing
routing tables, we need to configure a static route to the
WestCoast router. The IP address of the WestCoast network is
10.100.100.0/24 and the IP address to the router is
10.200.200.1/24.
The final part of the basic
configuration of the EastCoast router is to configure the BRI
interface and dialer interface.
Configure the dialer interface
with the IP address 10.200.200.2/24.
Configure the Service Profile
Identifiers: SPID1=51055580000001, SPID2=51055580010001
Configure the encapsulation type
to be PPP.
For security reasons, configure
the authentication to be CHAP.
To keep the line from staying
connected all of the time, configure the idle timeout to be 60
seconds.
Lastly, the router needs to know
where to dial. Configure the dialer map with the IP address of
the WestCoast router(10.200.200.1), the name of the router to be
dialed(WestCoast), and the number to dial(5551234).
Apply the dialer list to the
interface.
Don't forget the no shutdown command
on the interfaces.
Before configuring Priority
Queuing on the routers, test your configurations by pinging the
other router. This way you are insuring that your basic
configuration is correct before changing it.
Verify current queueing method in use
Enter the show interfaces command.
In the information returned by the
router, what does the router say the queueing method is for BRI
interface?
Configure Priority Queuing on
both the WestCoast, and the EastCoast routers. We have determined,
based on the applications in use, that TCP traffic should have a
high priority, ICMP should have a medium priority, UDP should have a
low priority, and all others should have a normal priority. Priority
lists differentiate priorities based on interface, port specific
protocols, or by protocol based on an access list. We will use the
priorities according to protocol based on an access list in order to
get all of the ports used by TCP, UDP, and ICMP. Our first step will
be to configure extended access lists to allow TCP, UDP, and ICMP
access for our priority lists. We will use the following commands to
set up our access lists.
WestCoast(config)#access-list 111
permit tcp any any
WestCoast(config)#access-list 112 permit icmp any any
WestCoast(config)#access-list 113 permit udp any any
EastCoast(config)#access-list 121 permit tcp any any
EastCoast(config)#access-list 122 permit icmp any any
EastCoast(config)#access-list 123 permit udp any any
Note: We are using different access
list numbers on the different routers to help differentiate between
the routers, but could have used any valid extended ip access list
number(100-199).
Once we have configured the
access lists, we need to configure our priority list for each of the
routers. The priority list should be according to the importance of
the traffic, as stated previously. The following commands will be
used to configure the router:
WestCoast(config)#priority-list 1
protocol ip high list 111
WestCoast(config)#priority-list 1 protocol ip medium list 112
WestCoast(config)#priority-list 1 protocol ip low list 113
EastCoast(config)#
priority-list 2 protocol ip high list 121
EastCoast(config)# priority-list 2 protocol ip medium list 122
EastCoast(config)# priority-list 2 protocol ip low list 123
Note: We are using different priority
list numbers on the different routers to help differentiate between
the routers, but could have used any valid priority list number.
The next step is to assign a
default queue. It is for all other traffic which has not yet been
given a priority. From our initial findings, we have decided that
all other traffic should have a normal priority. Here are the
commands for a default queue.
WestCoast(config)#priority-list 1
default normal
EastCoast(config)#priority-list 2 default normal
The final step in configuring our priority queuing list is to
apply the list to an interface. Since our WAN interface is where we
want to prioritize traffic, we will be applying it to the BRI 0
interface and dialer interface on each of the routers as follows:
Now, we need to check to make
sure that the routers are using priority queuing and that it is
operating correctly. Issue the following commands and observe the
responses from the router.
WestCoast#show queueing int bri0
EastCoast#show queueing int bri0
Optional challenge step to test the operation of PQ. From the
workstation/server connected to the WestCoast router, initiate a
large file transfer from the workstation/server connected to the
EastCoast router. Now initiate a continuous ping from EastCoast
workstation to the WestCoast workstation. Finally initiate a telnet
session between the two workstations/servers. Enter show queueing
interface bri 0 priority command on each of the routers.
What did the router respond with?
How has this response changed from
the first time that you issued the show queueing interface bri 0
command?
Change the priorities so that they are in the reverse order UDP high…TCP
low and retry the test as described previously. Enter show queueing
priority command on each of the routers.
What did the router respond with?
How has this response changed from
the first time that you issued the
show queueing priority
command?