CCNA Discovery 4 Chapter 4

Lab 4.1.2 Characterizing Network Applications

Step 1: Cable and configure the current network

Step 2: Configure NetFlow on the interfaces

Step 3: Verify the NetFlow configuration

Step 4: Create network data traffic

Step 5: View the data flows

Step 6: Stop the NetFlow capture

Step 7: Clean up

Step 8: Reflection

Consider the possible range of data flow types across a network and how a tool like NetFlow could be

implemented to assist in analyzing those flows.

List of data flow categories and types: Client to Client, Client to Server, Server to Client, and Server to Server Email, intranet web, database flows, document file flows

Number of separate flows of each type, size (bytes) of each flow, time each flow is on the network

Jawab:

Daftar kategori dan jenis aliran data: Client untuk Klien, Klien ke Server, Server untuk Client, dan Server ke Server
Email, web intranet, aliran database, file dokumen arus
Jumlah arus yang terpisah masing-masing jenis, ukuran (bytes) dari setiap aliran, waktu setiap aliran pada jaringan

Lab 4.2.3 Analyzing Network Traffic

Task 1: Design Network Access to FTP and Email Services

Step 1: FTP network considerations

Step 2: Email network considerations

Although customers expect immediate access to their emails, they usually do not expect emails to have

network priority over files that they are sharing or updating. Emails are expected to be delivered reliably and accurately. Generally, emails are not throughput-intensive, except when there are enterprise-wide mail-outs or there is a denial of service attack.

List some email policies that could control the volume of email data and the bandwidth used.

Membatasi ukuran lampiran email

Membatasi nomor penerima pesan email

Memastikan spam terfilter sebelum menjangkau LAN

Step 3: Configure and connect the host PCs

Task 2: Configure NBAR to Examine Network Traffic

Step 1: Enable NBAR Protocol Discovery

Step 2: Confirm that Protocol Discovery is configured

Task 3: Generate and Identify Network Traffic

Step 1: Generate FTP traffic

Step 2: Generate Email traffic

Step 3: Display the NBAR results

Although the data traffic in this lab may not be sufficient to generate values for the 5min Bit rate

(bps) and 5min Max Bit Rate (bps) fields, consider and discuss how these values would be applied

to designing an FTP and email network.

Jawab:

Dapat membantu menentukan rata-rata dan puncak kebutuhan bandwidth jaringan.

Step 4: Use NBAR to monitor other data traffic

Step 5: Clean up

Erase the configurations and reload the routers and switches. Disconnect and store the cabling. For PC hosts that are normally connected to other networks (such as the school LAN or to the Internet), reconnect the appropriate cabling and restore the TCP/IP settings

Challenge

This lab considered only the volume of FTP and email data traffic and its impact on network design. Reliable

access to servers is also important. In the space below, sketch a revised topology for this lab that would

provide redundancy for these services.

Lab 4.3.3 Prioritizing Traffic

Step 1: Gather the data traffic information

a. Read through the StadiumCompany case study curriculum.

List the current types of data traffic carried by the StadiumCompany network as well as the types

planned for the future.

b. Refer to the topology diagram and the stadium network diagram information.

List the possible data sources and destinations on the StadiumCompany network. For example, there

is likely to be data communications between the stadium management and the vendor management,

but not between Team A and Team B.

Step 2: Prioritize the data traffic

a.       List the source, destination, and traffic type that will be assigned the High priority queue.

b.      List the source, destination, and traffic type that will be assigned the Medium priority queue.

c.       List the source, destination, and traffic type that will be assigned the Normal priority queue

d.      List the source, destination, and traffic type that will be assigned the Low priority queue.

Step 3: Finalize the Data Priorities

a.       Discuss and review your data priority assignments with another student to ensure that it addresses allnpossible data. Modify your priorities as necessary.

b.      Highlight on the StadiumCompany topology diagram the device or devices where data traffic priority policies are likely to be configured.

Step 4: Reflection

Ideally, it may seem that all data traffic should be given a priority and queued accordingly. Consider and

discuss the potential for network performance to be negatively affected if this policy were implemented

everywhere on the network.

Jawab:

Delay data sensitif akan melihat prioritas yang sama sebagai non-delay data sensitif. Suara, video, diberi prioritas yang sama sebagai lalu lintas lainnya, dll

Lab 4.3.4 Exploring Network QoS

Step 1: Cable and configure the network

Step 2: Examine priority queue commands

Enter the following command and note the options available.

FC-CPE-1(config)#priority-list 1 ?

default Set priority queue for unspecified datagrams

interface Set priorities for packets from a named interface

protocol priority queueing by protocol

queue-limit Set queue limits for priority queues

Note some of the protocol options available.

FC-CPE-1(config)#priority-list 1 protocol ?

arp IP ARP

bridge Bridging

cdp Cisco Discovery Protocol

compressedtcp Compressed TCP (VJ)

http HTTP

ip IP

llc2 llc2

pad PAD links

pppoe PPP over Ethernet

snapshot Snapshot routing support

Note the IP protocol options available.

FC-CPE-1(config)#priority-list 1 protocol ip ?

Hig

medium

normal

low

Note the HTTP protocol options available.

FC-CPE-1(config)#priority-list 1 protocol http ?

high

medium

normal

low

Note the IP protocol high priority options available.

FC-CPE-1(config)#priority-list 1 protocol ip high ?

fragments Prioritize fragmented IP packets

gt Prioritize packets greater than a specified size

list To specify an access list

lt Prioritize packets less than a specified size

tcp Prioritize TCP packets 'to' or 'from' the specified port

udp Prioritize UDP packets 'to' or 'from' the specified port

<cr>

f. Note the IP protocol high priority TCP options available.

FC-CPE-1(config)#priority-list 1 protocol ip high tcp ?

<0-65535> Port number

domain Domain Name Service (53)

echo Echo (7)

ftp File Transfer Protocol (21)

ftp-data FTP data connections (20)

irc Internet Relay Chat (194)

nntp Network News Transport Protocol

(119)

pop3 Post Office Protocol v3 (110)

smtp Simple Mail Transport Protocol(25)

telnet Telnet (23)

www World Wide Web (HTTP, 80)

Over 30 port/service options are available.

Step 3: Configure an example priority queue

From the global configuration mode, issue the following commands.

FC-CPE-1(config)#priority-list 1 protocol http high

FC-CPE-1(config)#priority-list 1 protocol ip normal tcp ftp

FC-CPE-1(config)#priority-list 1 protocol ip medium tcp telnet

What do these commands establish?

Jawab:

Sebuah daftar prioritas (nomor "1") yang menetapkan paket HTTP yang akan ditandai sebagai prioritas tinggi, paket FTP rendah prioritas, dan Telnet paket sebagai prioritas menengah.

Step 4: Assign the priority list to an interface

a.       From the global configuration mode, issue the following commands to assign the priority list to interface serial 0/1/0.

FC-CPE-1(config)#int s0/1/0

FC-CPE-1(config-if)#priority-group 1

b.     Confirm the priority list configuration. From the privileged EXEC mode, issue the show runningconfig command.

Which statements in the configuration show that the priority list has been configured and applied

correctly?

interface Serial0/1/0

ip address 10.10.0.2 255.255.255.252

priority-group 1

priority-list 1 protocol http high

priority-list 1 protocol ip normal tcp ftp

priority-list 1 protocol ip medium tcp telnet

c. Confirm that issuing the show queueing priority command from the privileged EXEC mode

produces the following output:

FC-CPE-1#show queueing priority

Current DLCI priority queue configuration:

Current priority queue configuration:

List Queue Args

1 high protocol http

1 normal protocol ip tcp port ftp

1 medium protocol ip tcp port telnet

Step 5: Examine the priority queues operation

What is the significant difference when compared to the previous output form this command in

Step 5d?

Jawab:

Antrian Menengah sekarang memiliki jumlah paket, ini adalah prioritas yang ditugaskan untuk paket Telnet.

Step 6: Determine the priority queue requirements for the case study

a. Using the FilmCompany case study, what would you expect the priority queue requirements to be?

b. Discuss and compare your priorities with other students.

c. Amend your priority list statements to include traffic associated with the proposed network upgrade.

Step 7: Clean up

Erase the configurations and reload the routers and switches. Disconnect and store the cabling. For PC hosts that are normally connected to other networks (such as the school LAN or to the Internet), reconnect the appropriate cabling and restore the TCP/IP settings.

Challenge

The following privileged EXEC command displays the contents of packets inside a queue for a particular

interface:

show queue interface-type interface-number

However, in this lab, it is not likely that sufficient data traffic was generated at one time for the interface

queues to hold packets long enough to be inspected. Discuss how a network has to be load tested to ensure that all traffic priorities are met.

Lab 4.4.4 Investigating Video Traffic Impact on a Network

Step 1: Cable and configure the network

Step 2: Observe data traffic

Step 3: Stream the video file

Step 4: Observe both video and data traffic

Step 5: Observe the data flows with a different serial link clock rate

Step 6: Record your general observations

Compare the different download times and video quality.

Step 7: Clean up

Erase the configurations and reload the routers and switches. Disconnect and store the cabling. For PC hosts that are normally connected to other networks (such as the school LAN or to the Internet), reconnect the appropriate cabling and restore the TCP/IP settings.

Step 8: Reflection

Consider and discuss how video and other data traffic can share network resources while maintaining

acceptable performance.

Jawab:

Video dan lalu lintas data dapat berbagi sumber daya jaringan yang sama jika bandwidth yang memadai tersedia atau jika lalu lintas yang diprioritaskan. Data lalu lintas dapat ditunda sedikit untuk memungkinkan lebih banyak waktu trafik video sensitif untuk memanfaatkan bandwidth yang tersedia.

Lab 4.5.1 Identifying Traffic Flows

Step 1: Cable and configure the current network

a. Referring to the topology diagram, connect the console (or rollover) cable to the console port on the

router and the other cable end to the host computer with a DB-9 or DB-25 adapter to the COM 1 port.

Ensure that power has been applied to both the host computer and router.

b. Establish a HyperTerminal or other terminal emulation program to the router.

c. From the command prompt on Host1, ping between Host1 and Discovery Server to confirm network

connectivity. Troubleshoot and establish connectivity if the pings fail.

Step 2: Configure NetFlow on the interfaces

From the global configuration mode, issue the following commands to configure NetFlow:

FC-CPE-1(config)#interface fastethernet 0/0

FC-CPE-1(config-if)#ip flow egress

FC-CPE-1(config-if)#ip flow ingress

FC-CPE-1(config-if)#interface fastethernet 0/1

FC-CPE-1(config-if)#ip flow ingress

FC-CPE-1(config-if)#ip flow egress

Step 3: Verify the NetFlow configuration

a. From the privileged EXEC mode, issue the show ip flow interface command.

FC-CPE-1#show ip flow interface

FastEthernet0/0

ip flow ingress

ip flow egress

FastEthernet0/1

ip flow ingress

ip flow egress

Confirm that the output shown above is displayed. Troubleshoot your configuration if this output is not

displayed.

b. From the privileged EXEC mode, issue the following command to ensure that flow cache statistics are

reset:

FC-CPE-1#clear ip flow stats

Step 4: Create network data traffic

A range of network application data flows is to be generated and captured. Generate as many of the data

flows shown below as is possible in your lab. Your instructor will advise you of the particular applications that are available to be used in this lab.

a. Ping the Discovery Server from Host1 to generate a data flow.

From the command line of Host1, issue the command ping 172.17.1.1 -n 200

b. Telnet to the Discovery Server from Host1.

If Discovery Server is being used, issue the command telnet server.discovery.ccna from the

command prompt of Host1.

If Discovery Server is not being used, DNS is not configured , or if a terminal program such as

HyperTerminal or TeraTerm is being used, telnet from Host1 to 172.17.1.1.

c. On Host1, launch a web browser and enter the URL http://server.discovery.ccna

If Discovery Server is not being used or DNS is not configured, then use http://172.17.1.1 to access

the web services configured on that server.

d. Use FTP to download a file.

On Host1, launch a web browser and enter the URL ftp://server.discovery.ccna, or issue

ftp server.discovery.ccna from the command line. If DNS is not configured use the IP

address 172.17.1.1 instead of the domain name.

Download a file from the server.

e. If email accounts have been configured using the POP3 and SMTP services on Discovery Server,

send an email using one of these accounts.

Step 5: View the data flows

At the conclusion of the data flow, view the details by issuing the show ip cache flow command from privileged EXEC mode.

FC-CPE-1#show ip cache flow

Output similar to this will be displayed.

IP packet size distribution (3969 total packets):

1-32 64 96 128 160 192 224 256 288 320 352 384 416 448 480

.000 .351 .395 .004 .011 .001 .005 .009 .001 .002 .005 .001 .000 .000 .000

512 544 576 1024 1536 2048 2560 3072 3584 4096 4608

.000 .000 .013 .000 .195 .000 .000 .000 .000 .000 .000

IP Flow Switching Cache, 278544 bytes

2 active, 4094 inactive, 1368 added

22316 ager polls, 0 flow alloc failures

Active flows timeout in 30 minutes

Inactive flows timeout in 15 seconds

IP Sub Flow Cache, 17416 bytes

0 active, 1024 inactive, 0 added, 0 added to flow

0 alloc failures, 0 force free

1 chunk, 0 chunks added

last clearing of statistics 02:50:15

Protocol Total Flows Packets Bytes Packets Active(Sec) Idle(Sec)

-------- Flows /Sec /Flow /Pkt /Sec /Flow /Flow

TCP-Telnet 9 0.0 13 47 0.0 5.2 10.8

TCP-FTP 28 0.0 7 62 0.0 0.8 10.4

TCP-WWW 64 0.0 7 138 0.0 0.3 2.1

TCP-other 16 0.0 75 840 0.1 0.0 4.1

UDP-DNS 878 0.0 1 72 0.0 0.0 15.4

UDP-other 347 0.0 3 88 0.1 4.5 15.5

ICMP 26 0.0 1 70 0.0 0.8 15.4

Total: 1368 0.1 2 318 0.3 1.2 14.6

< output omitted >

From your output, list the name of each protocol with the number of flows. Answers vary. Examples shown.

Telnet 9 flows

FTP 28 flows

WWW 64 flows

DNS 878 flows

ICMP 26 flows

TCP other 16 flows

UDP other 347 flows

What was the total number of packets generated? 3969 packets

Which protocol generated the most packets? TCP other (75 x 16 = 1200)

Which protocol produced the most bytes per flow? TCP other (75 x 840 = 63000)

Which protocol's flows were on the network the longest time? Telnet 5.2 sec

Which protocol used the longest amount of network time? UDP other (4.5 x 347 = 1561.5 sec)

Step 6: Clean up

Erase the configurations and reload the routers and switches. Disconnect and store the cabling. For PC hosts that are normally connected to other networks (such as the school LAN or to the Internet), reconnect the appropriate cabling and restore the TCP/IP settings.

Step 7: Reflection

Create a projected applications document listing the applications planned to use the network.

Application Type	Application	Protocol	Prioritas	Comments
Email	MS Outlook	SMTP	Menengah	Semua pengguna
Voice	Call Manager/SIP	VRTP	Tinggi	Semua pengguna
Web	Apache Server	HTTP	Rendah	Semua pengguna
Database	SQL Server	TCP	Menengah	Restricted user

Lab 4.5.2 Diagramming Intranet Traffic Flows

Step 1: Cable and configure the current network

a. Referring to the topology diagram, connect the console (or rollover) cable to the console port on the

router and the other cable end to the PC1 computer with a DB-9 or DB-25 adapter to the COM 1 port.

Ensure that power has been applied to both the host computer and router.

b. Establish a HyperTerminal or other terminal emulation program to the router.

c. Ping between Host1 and Host2 and between the hosts and Discovery Server to confirm network

connectivity. Troubleshoot and establish connectivity if the pings fail.

Step 2: Configure NetFlow on the interfaces

From the global configuration mode, issue the following commands to configure NetFlow:

FC-CPE-1(config)#interface fastethernet 0/0

FC-CPE-1(config-if)#ip flow egress

FC-CPE-1(config-if)#ip flow ingress

FC-CPE-1(config-if)#interface fastethernet 0/1

FC-CPE-1(config-if)#ip flow ingress

FC-CPE-1(config-if)#ip flow egress

FC-CPE-1(config-if)#end

Step 3: Verify the NetFlow configuration

a. From the privileged EXEC mode, issue the show ip flow interface command.

FC-CPE-1#show ip flow interface

FastEthernet0/0

ip flow ingress

ip flow egress

FastEthernet0/1

ip flow ingress

ip flow egress

Confirm that the output shown above is displayed. Troubleshoot your configuration if this output is not

displayed.

b. From the privileged EXEC mode, issue the following command to ensure that flow cache statistics are

reset:

FC-CPE-1#clear ip flow stats

Step 4: Create network data traffic

A range of network application data flows between the Host1, Host2, and the server is to be generated and captured. Generate as many of the data flows shown below as is possible in your lab. Your instructor will advise you of the particular applications that are available to be used in this lab.

a. On Host1, launch a web browser and enter the URL http://server.discovery.ccna

b. On Host2, launch a web browser and enter the URL http://server.discovery.ccna

If Discovery Server is not being used, then use http://172.17.1.1 to access the web services

configured on that server.

c. Use FTP to download a file.

On Host1 and Host2, launch a web browser and enter the URL ftp://server.discovery.ccna,

or issue ftp server.discovery.ccna from the command line. If DNS is not configured, use the

IP address 172.17.1.1 instead of the domain name.

Download a file from the server.

d. If email accounts have been configured using the POP3 and SMTP services on Discovery Server,

send two emails between users on Host1 and Host2 using these accounts.

e. Set up Windows file sharing between Host1 and Host2 and copy a file from one to the other.

Step 5: View the data flows

At the conclusion of the data flow, view the details by issuing the show ip cache verbose flow

command from privileged EXEC mode.

FC-CPE-1#show ip cache verbose flow

Application Type	Source	Destination	Comments
Web	Intranet Web Server	Host1
Web	Intranet Web Server	Host2
File Transfer	Intranet File Server	Host1
File Transfer	Intranet File Server	Host2
Email	Host1	Email Server
Email	Host2	Email Server
File Share	Host1	Host2

Step 6: Clean up

Erase the configurations and reload the routers and switches. Disconnect and store the cabling. For PC hosts that are normally connected to other networks (such as the school LAN or to the Internet), reconnect the appropriate cabling and restore the TCP/IP settings.

Challenge

This lab simulates LAN data traffic. The LAN data flows of a production network would be much more

extensive and recorded over a greater period of time, perhaps a full working week.

a. On the FilmCompany initial current network topology shown on the next page, add PC host and

printer icons as listed for each VLAN. Draw a circle that encloses the local LAN segments.

b. Then, using the data flows recorded in this lab as a starting point, use different colors to mark the

different LAN data flows between hosts and the server.

Lab 4.5.3 Diagramming Traffic Flows to and from Remote Sites

Step 1: Cable and configure the current network

a. Cable the topology given in the diagram. Ensure that power has been applied to both the host

computer and router.

b. Establish a HyperTerminal or other terminal emulation program to the routers and configure the

hostname and interfaces shown in the table.

c. Set a clock rate on the DCE interface of the serial link between R2 and R3. Routing will have to be

configured on the three routers to establish data communications.

d. From PC1, ping and PC2 and Discovery Server to confirm network connectivity. Troubleshoot and

establish connectivity if the pings fail.

Step 2: Configure NetFlow on the router FC-CPE-1 interfaces

From the global configuration mode, issue the following commands to configure NetFlow on the router FCCPE-1.

FC-CPE-1(config)#interface fastethernet 0/0

FC-CPE-1(config-if)#ip flow egress

FC-CPE-1(config-if)#ip flow ingress

FC-CPE-1(config-if)#interface fastethernet 0/1

FC-CPE-1(config-if)#ip flow ingress

FC-CPE-1(config-if)#ip flow egress

Step 3: Verify the NetFlow configuration

a. From the privileged EXEC mode on router FC-CPE-1, issue the show ip flow interface

command.

FC-CPE-1#show ip flow interface

FastEthernet0/0

ip flow ingress

ip flow egress

FastEthernet0/1

ip flow ingress

ip flow egress

Confirm that the output shown above is displayed. Troubleshoot your configuration if this output is not

displayed.

b. From the privileged EXEC mode, issue the following command to ensure that flow cache statistics are

reset:

FC-CPE-1#clear ip flow stats

Step 4: Configure NetFlow on the router FC-CPE-2 interfaces

From the global configuration mode, issue the following commands to configure NetFlow on the router FCCPE-

2:

FC-CPE-2(config)#interface fastethernet 0/0

FC-CPE-2(config-if)#ip flow egress

FC-CPE-2(config-if)#ip flow ingress

FC-CPE-1(config-if)#interface fastethernet 0/1

FC-CPE-2(config-if)#ip flow ingress

FC-CPE-2(config-if)#ip flow egress

FC-CPE-1(config-if)#interface serial 0/1/0

FC-CPE-2(config-if)#ip flow ingress

FC-CPE-2(config-if)#ip flow egress

FC-CPE-2(config-if)#end

Step 5: Verify the NetFlow configuration

a. From the privileged EXEC mode on router FC-CPE-2, issue the show ip flow interface

command.

FC-CPE-2#show ip flow interface

FastEthernet0/0

ip flow ingress

ip flow egress

FastEthernet0/1

ip flow ingress

ip flow egress

Serial0/1/0

ip flow ingress

ip flow egress

Confirm that the output shown above is displayed. Troubleshoot your configuration if this output is not

displayed.

b. From the privileged EXEC mode, issue the following command to ensure that flow cache statistics are

reset:

FC-CPE-2#clear ip flow stats

Step 6: Configure NetFlow on the router ISP interfaces

From the global configuration mode, issue the following commands to configure NetFlow on the router ISP:

ISP(config)#interface fastethernet 0/1

ISP(config-if)#ip flow ingress

ISP(config-if)#ip flow egress

ISP(config-if)#interface serial 0/0/0

ISP(config-if)#ip flow ingress

ISP(config-if)#ip flow egress

ISP(config-if)#end

Step 7: Verify the NetFlow configuration

a. From the privileged EXEC mode on router ISP, issue the show ip flow interface command.

ISP#show ip flow interface

FastEthernet0/1

ip flow ingress

ip flow egress

Serial0/1/0

ip flow ingress

ip flow egress

Confirm that the output shown above is displayed. Troubleshoot your configuration if this output is not

displayed.

b. From the privileged EXEC mode, issue the following command to ensure that flow cache statistics are

reset:

ISP#clear ip flow stats

Step 8: Create network data traffic

A range of network application data flows between the remote site, the FilmCompany LAN, and the network server is to be generated and captured. Generate as many of the data flows shown below as is possible in your lab. Your instructor will advise you of the particular applications that are available to be used in this lab.

a. On both PCs launch a web browser and enter the URL http://server.discovery.ccna

If Discovery Server is not being used, or DNS is not configured, then use http://172.17.1.1 to

access the web services configured on that server..

b. Use FTP to download a file.

On both PCs, launch a web browser and enter the URL ftp://server.discovery.ccna, or issue

ftp server.discovery.ccna from the command line. If DNS is not configured use 172.17.1.1

instead of the domain name. Download a file from the server.

c. If email accounts have been configured using the POP3 and SMTP services on Discovery Server,

send two emails in each direction between the user on the LAN and the Remote User using these

accounts.

d. To simulate data traffic between the two PCs, ping between them. Attempt to establish a Telnet

session between the two PCs. If file sharing has been enabled, copy a file in both directions between

the two.

Step 9: View the data flows

a. At the conclusion of the data flow, view the details by issuing the show ip cache verbose flow

command from privileged EXEC mode on each router.

FC-CPE-1#show ip cache verbose flow

FC-CPE-2#show ip cache verbose flow

ISP#show ip cache verbose flow

Router 1 – Sample Output

FC-CPE-1#show ip cache verbose flow

IP packet size distribution (1050 total packets):

1-32 64 96 128 160 192 224 256 288 320 352 384 416 448 480

.000 .672 .278 .015 .000 .007 .000 .000 .000 .000 .000 .000 .001 .003 .000

512 544 576 1024 1536 2048 2560 3072 3584 4096 4608

.001 .000 .003 .011 .003 .000 .000 .000 .000 .000 .000

IP Flow Switching Cache, 278544 bytes

1 active, 4095 inactive, 150 added

2280 ager polls, 0 flow alloc failures

Active flows timeout in 30 minutes

Inactive flows timeout in 15 seconds

IP Sub Flow Cache, 21640 bytes

1 active, 1023 inactive, 27 added, 27 added to flow

0 alloc failures, 0 force free

1 chunk, 0 chunks added

last clearing of statistics 00:12:31

Protocol Total Flows Packets Bytes Packets Active(Sec) Idle(Sec)

-------- Flows /Sec /Flow /Pkt /Sec /Flow /Flow

TCP-FTP 8 0.0 7 54 0.0 3.7 12.1

TCP-WWW 8 0.0 5 196 0.0 0.2 1.5

TCP-SMTP 16 0.0 15 72 0.3 15.8 1.7

TCP-other 32 0.0 11 77 0.5 2.2 1.5

UDP-DNS 49 0.0 5 67 0.3 6.1 15.6

UDP-other 38 0.0 1 83 0.0 0.0 15.4

Total: 151 0.2 6 77 1.4 4.3 10.2

SrcIf SrcIPaddress DstIf DstIPaddress Pr TOS Flgs Pkts

Port Msk AS Port Msk AS NextHop B/Pk Active

FC-CPE-1#

Router 2 – Sample Output

FC-CPE-2#show ip cache verbose flow

IP packet size distribution (982 total packets):

1-32 64 96 128 160 192 224 256 288 320 352 384 416 448 480

.000 .665 .164 .016 .000 .008 .000 .000 .000 .000 .000 .000 .002 .004 .000

512 544 576 1024 1536 2048 2560 3072 3584 4096 4608

.002 .000 .004 .128 .004 .000 .000 .000 .000 .000 .000

IP Flow Switching Cache, 278544 bytes

3 active, 4093 inactive, 145 added

2617 ager polls, 0 flow alloc failures

Active flows timeout in 30 minutes

Inactive flows timeout in 15 seconds

IP Sub Flow Cache, 21640 bytes

2 active, 1022 inactive, 50 added, 50 added to flow

0 alloc failures, 0 force free

1 chunk, 0 chunks added

last clearing of statistics 00:11:43

Protocol Total Flows Packets Bytes Packets Active(Sec) Idle(Sec)

-------- Flows /Sec /Flow /Pkt /Sec /Flow /Flow

TCP-Telnet 6 0.0 3 45 0.0 3.6 10.7

TCP-FTP 8 0.0 7 54 0.0 3.7 11.8

TCP-WWW 8 0.0 5 196 0.0 0.2 1.7

TCP-SMTP 16 0.0 15 72 0.3 15.8 1.6

TCP-other 32 0.0 11 77 0.5 2.2 1.4

UDP-DNS 8 0.0 1 69 0.0 0.1 15.3

UDP-other 59 0.0 1 55 0.0 0.0 15.4

ICMP 9 0.0 4 60 0.0 4.3 15.4

Total: 146 0.2 5 76 1.2 2.8 9.7

SrcIf SrcIPaddress DstIf DstIPaddress Pr TOS Flgs Pkts

Port Msk AS Port Msk AS NextHop B/Pk Active

Fa0/1 0.0.0.0 Null 255.255.255.255 11 00 10 120

0044 /0 0 0043 /0 0 0.0.0.0 604 729.9

Se0/1/0 10.10.10.2 Null 224.0.0.9 11 C0 10 1

0208 /0 0 0208 /0 0 0.0.0.0 52 0.0

IPM: 0 0

FC-CPE-2#

Router 3 – Sample Output

ISP#show ip cache verbose flow

IP packet size distribution (502 total packets):

1-32 64 96 128 160 192 224 256 288 320 352 384 416 448 480

.000 .709 .225 .015 .000 .007 .000 .001 .000 .000 .000 .000 .000 .007 .000

512 544 576 1024 1536 2048 2560 3072 3584 4096 4608

.003 .000 .003 .015 .007 .000 .000 .000 .000 .000 .000

IP Flow Switching Cache, 278544 bytes

1 active, 4095 inactive, 90 added

1274 ager polls, 0 flow alloc failures

Active flows timeout in 30 minutes

Inactive flows timeout in 15 seconds

IP Sub Flow Cache, 21640 bytes

1 active, 1023 inactive, 25 added, 25 added to flow

0 alloc failures, 0 force free

1 chunk, 0 chunks added

last clearing of statistics 00:11:21

Protocol Total Flows Packets Bytes Packets Active(Sec) Idle(Sec)

-------- Flows /Sec /Flow /Pkt /Sec /Flow /Flow

TCP-Telnet 6 0.0 3 45 0.0 3.6 10.7

TCP-WWW 8 0.0 5 196 0.0 0.2 1.5

TCP-SMTP 8 0.0 18 70 0.2 21.3 1.5

TCP-other 16 0.0 12 83 0.2 4.3 1.5

UDP-DNS 8 0.0 1 69 0.0 0.1 15.4

UDP-other 33 0.0 1 87 0.0 0.0 15.4

ICMP 10 0.0 4 60 0.0 5.4 15.5

Total: 89 0.1 5 85 0.7 3.6 10.1

SrcIf SrcIPaddress DstIf DstIPaddress Pr TOS Flgs Pkts

Port Msk AS Port Msk AS NextHop B/Pk Active

Se0/1/0 10.10.10.1 Null 224.0.0.9 11 C0 10 1

0208 /0 0 0208 /0 0 0.0.0.0 92 0.0

IPM: 0 0

ISP#

b. Examine the output and record the different data flows for each router.

c. Discuss and compare the data flows for each router. Particularly consider how recording these flows

can assist in understanding which network devices and resources are used for particular flows.

Step 10: Clean up

Erase the configurations and reload the routers and switches. Disconnect and store the cabling. For PC hosts that are normally connected to other networks (such as the school LAN or to the Internet), reconnect the appropriate cabling and restore the TCP/IP settings.

Challenge

This lab simulates the flow of traffic to and from FilmCompany remote sites. These data flows for a production network would be much more extensive and recorded over a greater period of time, perhaps a full working week. Additionally, remote access would most likely be established using VPNs (Virtual Private Networks) across the Internet or a WAN. On the FilmCompany initial current network topology shown on the next page, add two remote site hosts attached to the "far" side of the cloud icon. Draw a circle that encloses the remote access links to the FilmCompany network and server. In this case study initially, the FilmCompany remote sites access its network across the Internet.

One of the objects of this analysis is to establish the benefits of using a dedicated WAN link using Frame

Relay for the stadium-based remote sites to access the FilmCompany network.

Using the data flows recorded in this lab as a starting point, use different colors to mark on the diagram the different data flows between the remote hosts and devices on the FilmCompany network.

Lab 4.5.4 Diagramming External Traffic Flows

Step 1: Cable and configure the current network

a. Cable the topology given in the diagram. Ensure that power has been applied to both the host

computer and router.

b. Establish a HyperTerminal or other terminal emulation program to the routers and configure the

hostname and interfaces shown in the table.

c. Set a clock rate on the DCE interface of the serial link between R2 and R3. Routing will have to be

configured on the three routers to establish data communications.

d. From PC1 ping both PC2 and Discovery Server to confirm network connectivity. Troubleshoot and

establish connectivity if the pings fail.

Step 2: Configure NetFlow on router FC-CPE-1 interfaces

From the global configuration mode, issue the following commands to configure NetFlow on the router FCCPE-1.

FC-CPE-1(config)#interface fastethernet 0/0

FC-CPE-1(config-if)#ip flow egress

FC-CPE-1(config-if)#ip flow ingress

FC-CPE-1(config-if)#interface fastethernet 0/1

FC-CPE-1(config-if)#ip flow ingress

FC-CPE-1(config-if)#ip flow egress

FC-CPE-1(config-if)#end

Step 3: Verify the NetFlow configuration

a. From the privileged EXEC mode on router FC-CPE-1, issue the show ip flow interface

command.

FC-CPE-1#show ip flow interface

FastEthernet0/0

ip flow ingress

ip flow egress

FastEthernet0/1

ip flow ingress

ip flow egress

Confirm that the output shown above is displayed. Troubleshoot your configuration if this output is not

displayed.

b. From the privileged EXEC mode, issue the following command to ensure that flow cache statistics are

reset:

FC-CPE-1#clear ip flow stats

Step 4: Configure NetFlow on router FC-CPE-2 interfaces

From the global configuration mode, issue the following commands to configure NetFlow on the router FCCPE-2:

FC-CPE-2(config)#interface fastethernet 0/0

FC-CPE-2(config-if)#ip flow egress

FC-CPE-2(config-if)#ip flow ingress

FC-CPE-2(config-if)#interface fastethernet 0/1

FC-CPE-2(config-if)#ip flow ingress

FC-CPE-2(config-if)#ip flow egress

FC-CPE-2(config-if)#interface serial 0/1/0

FC-CPE-2(config-if)#ip flow ingress

FC-CPE-2(config-if)#ip flow egress

FC-CPE-2(config-if)#end

Step 5: Verify the NetFlow configuration

a. From the privileged EXEC mode on router FC-CPE-2, issue the show ip flow interface

command.

FC-CPE-2#show ip flow interface

FastEthernet0/0

ip flow ingress

ip flow egress

FastEthernet0/1

ip flow ingress

ip flow egress

Serial0/1/0

ip flow ingress

ip flow egress

Confirm that the output shown above is displayed. Troubleshoot your configuration if this output is not

displayed.

b. From the privileged EXEC mode, issue the following command to ensure that flow cache statistics are

reset:

FC-CPE-2#clear ip flow stats

Step 6: Configure NetFlow on router ISP interfaces

From the global configuration mode, issue the following commands to configure NetFlow on the router ISP:

ISP(config)#interface fastethernet 0/1

ISP(config-if)#ip flow ingress

ISP(config-if)#ip flow egress

ISP(config-if)#interface serial 0/1/0

ISP(config-if)#ip flow ingress

ISP(config-if)#ip flow egress

ISP(config-if)#end

Step 7: Verify the NetFlow configuration

a. From the privileged EXEC mode on router ISP, issue the show ip flow interface command.

ISP#show ip flow interface

FastEthernet0/1

ip flow ingress

ip flow egress

Serial0/1/0

ip flow ingress

ip flow egress

Confirm that the output shown above is displayed. Troubleshoot your configuration if this output is not

displayed.

b. From the privileged EXEC mode, issue the following command to ensure that flow cache statistics are reset:

ISP#clear ip flow stats

Step 8: Create network data traffic

A range of Internet application data flows between PC2 (the Internet) and the FilmCompany network is to be generated and captured. Generate as many of the data flows shown below as it is possible in your lab. Your instructor will advise you of the particular applications that are available and to be used in this lab.

a. On PC2, launch a web browser and enter the URL http://server.discovery.ccna

If Discovery Server is not being used, or DNS is not configured, then use http://172.17.1.1 to

access the web services configured on that server.

b. Use FTP to download a file.

On PC2, launch a web browser and enter the URL ftp://server.discovery.ccna, or issue ftp

server.discovery.ccna from the command line. If DNS is not configured use the IP address

172.17.1.1 instead of the domain name. (example: http://172.17.1.1 )

Download a file from the server.

c. If email accounts have been configured using the POP3 and SMTP services on Discovery Server,

send two emails from PC2 using these accounts.

Step 9: View the data flows

a. At the conclusion of the data flow, view the details by issuing the show ip cache verbose flow

command from privileged EXEC mode on each router.

FC-CPE-1#show ip cache verbose flow

FC-CPE-2#show ip cache verbose flow

ISP#show ip cache verbose flow

b. Examine the output and record the different data flows for each router.

c. Discuss and compare the data flows for each router. Particularly consider how these flows differ from

Lab 4.5.3 and the implications this has in understanding which network devices and resources are

used for particular flows.

Step 10: Clean up

Erase the configurations and reload the routers and switches. Disconnect and store the cabling. For PC hosts that are normally connected to other networks (such as the school LAN or to the Internet), reconnect the appropriate cabling and restore the TCP/IP settings.

Challenge

This lab simulates the flow of traffic to and from FilmCompany network and the Internet. These data flows for a production network would be much more extensive and recorded over a greater period of time, perhaps a full working week. On the FilmCompany initial current network topology shown on the next page, highlight the network Internet link. Using the data flows recorded in this lab as a starting point, use different colors to mark on the diagram the different possible data flows between the hosts and devices on the FilmCompany network to and from the Internet.

Lab 4.5.5 Diagramming Extranet Traffic Flows

Step 1: Cable and configure the current network

a. Cable the topology given in the diagram. Ensure that power has been applied to both the host

computer and router.

b. Establish a HyperTerminal or other terminal emulation program to the routers and configure the

hostname and interfaces shown in the table.

c. Set a clock rate on the DCE interface of the serial link between R2 and R3. Routing will have to be

configured on the three routers to establish data communications.

d. From PC1, ping PC2 and Discovery Server to confirm network connectivity. Troubleshoot and

establish connectivity if the pings fail.

Step 2: Configure NetFlow on router FC-CPE-1 interfaces

From the global configuration mode, issue the following commands to configure NetFlow on the router FCCPE-1.

FC-CPE-1(config)#interface fastethernet 0/0

FC-CPE-1(config-if)#ip flow egress

FC-CPE-1(config-if)#ip flow ingress

FC-CPE-1(config-if)#interface fastethernet 0/1

FC-CPE-1(config-if)#ip flow ingress

FC-CPE-1(config-if)#ip flow egress

FC-CPE-1(config-if)#end

Step 3: Verify the NetFlow configuration

a. From the privileged EXEC mode on router FC-CPE-1, issue the show ip flow interface

command.

FC-CPE-1#show ip flow interface

FastEthernet0/0

ip flow ingress

ip flow egress

FastEthernet0/1

ip flow ingress

ip flow egress

Confirm that the output shown above is displayed. Troubleshoot your configuration if this output is not

displayed.

b. From the privileged EXEC mode, issue the following command to ensure that flow cache statistics are

reset:

FC-CPE-1#clear ip flow stats

Step 4: Configure NetFlow on router FC-CPE-2 interfaces

From the global configuration mode, issue the following commands to configure NetFlow on the router FCCPE-2:

FC-CPE-2(config)#interface fastethernet 0/0

FC-CPE-2(config-if)#ip flow egress

FC-CPE-2(config-if)#ip flow ingress

FC-CPE-2(config-if)#interface fastethernet 0/1

FC-CPE-2(config-if)#ip flow ingress

FC-CPE-2(config-if)#ip flow egress

FC-CPE-2(config-if)#interface serial 0/1/0

FC-CPE-2(config-if)#ip flow ingress

FC-CPE-2(config-if)#ip flow egress

FC-CPE-2(config-if)#end

Step 5: Verify the NetFlow configuration

a. From the privileged EXEC mode on router FC-CPE-2, issue the show ip flow interface

command.

FC-CPE-2#show ip flow interface

FastEthernet0/0

ip flow ingress

ip flow egress

FastEthernet0/1

ip flow ingress

ip flow egress

Serial0/1/0

ip flow ingress

ip flow egress

Confirm that the output shown above is displayed. Troubleshoot your configuration if this output is not

displayed.

b. From the privileged EXEC mode, issue the following command to ensure that flow cache statistics are

reset:

FC-CPE-2#clear ip flow stats

Step 6: Configure NetFlow on router ISP interfaces

From the global configuration mode, issue the following commands to configure NetFlow on the router ISP:

ISP(config)#interface fastethernet 0/1

ISP(config-if)#ip flow ingress

ISP(config-if)#ip flow egress

ISP(config-if)#interface serial 0/1/0

ISP(config-if)#ip flow ingress

ISP(config-if)#ip flow egress

ISP(config-if)#end

Step 7: Verify the NetFlow configuration

a. From the privileged EXEC mode on router ISP, issue the show ip flow interface command.

ISP#show ip flow interface

FastEthernet0/1

ip flow ingress

ip flow egress

Serial0/1/0

ip flow ingress

ip flow egress

Confirm that the output shown above is displayed. Troubleshoot your configuration if this output is not

displayed.

b. From the privileged EXEC mode, issue the following command to ensure that flow cache statistics are

reset:

ISP#clear ip flow stats

Step 8: Create network data traffic

Ideally, a range of network application data flows between the trusted extranet host PC2 and PC1 on the

FilmCompany LAN should be generated and captured. Generate as many of the data flows shown below as is possible in your lab. Your instructor will advise you of the particular applications that are available and to be used in this lab.

To simulate data traffic between the two PCs:

a. Ping between them.

b. Attempt to establish a Telnet session between the two PCs.

c. If you have rights, enable file sharing and copy a file in both directions between the two PCs.

Step 9: View the data flows

a. At the conclusion of the data flow, view the details by issuing the show ip cache verbose flow

command from privileged EXEC mode on each router.

FC-CPE-1#show ip cache verbose flow

FC-CPE-2#show ip cache verbose flow

ISP#show ip cache verbose flow

Router 1 – Output

FC-CPE-1#show ip cache verbose flow

IP packet size distribution (12 total packets):

1-32 64 96 128 160 192 224 256 288 320 352 384 416 448 480

.000 .000 1.00 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000

512 544 576 1024 1536 2048 2560 3072 3584 4096 4608

.000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000

IP Flow Switching Cache, 278544 bytes

0 active, 4096 inactive, 12 added

192 ager polls, 0 flow alloc failures

Active flows timeout in 30 minutes

Inactive flows timeout in 15 seconds

IP Sub Flow Cache, 21640 bytes

0 active, 1024 inactive, 8 added, 8 added to flow

0 alloc failures, 0 force free

1 chunk, 0 chunks added

last clearing of statistics 00:03:38

Protocol Total Flows Packets Bytes Packets Active(Sec) Idle(Sec)

-------- Flows /Sec /Flow /Pkt /Sec /Flow /Flow

UDP-DNS 2 0.0 1 70 0.0 0.0 15.7

UDP-other 10 0.0 1 87 0.0 0.0 15.5

Total: 12 0.0 1 84 0.0 0.0 15.5

SrcIf SrcIPaddress DstIf DstIPaddress Pr TOS Flgs Pkts

Port Msk AS Port Msk AS NextHop B/Pk Active

FC-CPE-1#

Router 2 – Output

FC-CPE-2#show ip cache verbose flow

IP packet size distribution (5223 total packets):

1-32 64 96 128 160 192 224 256 288 320 352 384 416 448 480

.000 .303 .030 .142 .031 .034 .001 .002 .001 .000 .000 .004 .000 .075 .000

512 544 576 1024 1536 2048 2560 3072 3584 4096 4608

.000 .000 .000 .020 .351 .000 .000 .000 .000 .000 .000

IP Flow Switching Cache, 278544 bytes

9 active, 4087 inactive, 62 added

1970 ager polls, 0 flow alloc failures

Active flows timeout in 30 minutes

Inactive flows timeout in 15 seconds

IP Sub Flow Cache, 21640 bytes

0 active, 1024 inactive, 20 added, 20 added to flow

0 alloc failures, 0 force free

1 chunk, 0 chunks added

last clearing of statistics 00:04:31

Protocol Total Flows Packets Bytes Packets Active(Sec) Idle(Sec)

-------- Flows /Sec /Flow /Pkt /Sec /Flow /Flow

TCP-Telnet 18 0.0 3 45 0.2 3.6 10.9

TCP-other 4 0.0 1 40 0.0 0.0 15.5

UDP-DNS 2 0.0 1 70 0.0 0.0 15.4

UDP-other 22 0.0 1 53 0.0 0.0 15.3

ICMP 8 0.0 14 60 0.4 13.9 15.2

Total: 54 0.2 3 54 0.7 3.2 13.8

SrcIf SrcIPaddress DstIf DstIPaddress Pr TOS Flgs Pkts

Port Msk AS Port Msk AS NextHop B/Pk Active

Fa0/1 0.0.0.0 Null 255.255.255.255 11 00 10 222

0044 /0 0 0043 /0 0 0.0.0.0 604 1356.9

Fa0/1 10.0.0.200 Se0/1/0 10.20.0.200 06 00 18 1368

01BD /0 0 06AA /0 0 0.0.0.0 970 184.9

Fa0/1 10.0.0.200 Se0/1/0* 10.20.0.200 06 00 18 1368

01BD /0 0 06AA /0 0 0.0.0.0 970 184.9

FFlags: 01

Se0/1/0 10.20.0.200 Fa0/0 172.17.1.1 11 00 10 5

0404 /0 0 0035 /0 0 0.0.0.0 62 4.3

Se0/1/0 10.20.0.200 Fa0/0* 172.17.1.1 11 00 10 5

0404 /0 0 0035 /0 0 0.0.0.0 62 4.3

FFlags: 01

Fa0/0 172.17.1.1 Se0/1/0* 10.20.0.200 11 00 10 5

0035 /0 0 0404 /0 0 0.0.0.0 62 4.3

FFlags: 01

Fa0/0 172.17.1.1 Se0/1/0 10.20.0.200 11 00 10 5

0035 /0 0 0404 /0 0 0.0.0.0 62 4.3

Se0/1/0 10.20.0.200 Fa0/1 10.0.0.200 06 00 18 1152

SrcIf SrcIPaddress DstIf DstIPaddress Pr TOS Flgs Pkts

Port Msk AS Port Msk AS NextHop B/Pk Active

06AA /0 0 01BD /0 0 0.0.0.0 71 184.9

Se0/1/0 10.20.0.200 Fa0/1* 10.0.0.200 06 00 18 1210

06AA /0 0 01BD /0 0 0.0.0.0 71 194.7

FFlags: 01

Fa0/0 10.10.0.1 Null 224.0.0.9 11 C0 10 1

0208 /0 0 0208 /0 0 0.0.0.0 52 0.0

IPM: 0 0

FC-CPE-2#

Router 3 – Output

ISP#show ip cache verbose flow

IP packet size distribution (6724 total packets):

1-32 64 96 128 160 192 224 256 288 320 352 384 416 448 480

.000 .306 .029 .138 .031 .032 .001 .001 .001 .000 .000 .003 .000 .080 .001

512 544 576 1024 1536 2048 2560 3072 3584 4096 4608

.000 .000 .000 .008 .362 .000 .000 .000 .000 .000 .000

IP Flow Switching Cache, 278544 bytes

5 active, 4091 inactive, 54 added

1881 ager polls, 0 flow alloc failures

Active flows timeout in 30 minutes

Inactive flows timeout in 15 seconds

IP Sub Flow Cache, 21640 bytes

1 active, 1023 inactive, 12 added, 12 added to flow

0 alloc failures, 0 force free

1 chunk, 0 chunks added

last clearing of statistics 00:05:44

Protocol Total Flows Packets Bytes Packets Active(Sec) Idle(Sec)

-------- Flows /Sec /Flow /Pkt /Sec /Flow /Flow

TCP-Telnet 18 0.0 3 45 0.1 3.6 10.7

TCP-other 4 0.0 1 40 0.0 0.0 15.7

UDP-DNS 4 0.0 3 63 0.0 2.1 15.5

UDP-other 16 0.0 1 77 0.0 0.0 15.4

ICMP 8 0.0 14 60 0.3 13.4 15.5

Total: 50 0.1 4 58 0.6 3.6 13.7

SrcIf SrcIPaddress DstIf DstIPaddress Pr TOS Flgs Pkts

Port Msk AS Port Msk AS NextHop B/Pk Active

Se0/1/0 10.0.0.200 Fa0/1 10.20.0.200 06 00 18 1794

01BD /0 0 06AA /0 0 0.0.0.0 989 245.1

Se0/1/0 10.0.0.200 Fa0/1* 10.20.0.200 06 00 18 1794

01BD /0 0 06AA /0 0 0.0.0.0 989 245.1

FFlags: 01

Fa0/1 10.20.0.200 Se0/1/0 10.0.0.200 06 00 18 1502

06AA /0 0 01BD /0 0 0.0.0.0 69 245.0

Fa0/1 10.20.0.200 Se0/1/0* 10.0.0.200 06 00 18 1502

06AA /0 0 01BD /0 0 0.0.0.0 69 245.0

FFlags: 01

ISP#

b. Examine the output and record the different data flows for each router.

c. Discuss and compare the data flows for each router. Particularly consider how these flows differ from

the previous Labs and the implications this has in understanding which network devices and

resources are used for particular flows.

Step 10: Clean up

Erase the configurations and reload the routers and switches. Disconnect and store the cabling. For PC hosts that are normally connected to other networks (such as the school LAN or to the Internet), reconnect the appropriate cabling and restore the TCP/IP settings.

Challenge

This lab simulates the flow of traffic to and from FilmCompany and from selected trusted partners and

customers. These data flows for a production network would be much more extensive and recorded over a greater period of time, perhaps a full working week. Additionally, remote access from trusted sites would most likely be established using VPNs (Virtual Private Networks) across the Internet or a WAN.

On the FilmCompany initial current network topology shown on the next page, add two trusted remote site

hosts attached to the "far" side of the cloud icon. Draw a circle that encloses the remote access links to the FilmCompany network and server. In this case study, initially the FilmCompany remote sites access its network across the Internet. One of the objects of this analysis is to establish the benefits of using a dedicated WAN link using Frame Relay for the stadium-based remote sites to access the FilmCompany network. Then, using the data flows recorded in this lab as a starting point, use different colors to mark on the diagram the different extranet data flows between the trusted remote hosts and devices on the FilmCompany network. Diagram traffic flows to and from selected trusted partners, customers, and vendors.