Lab 4.1.6 Using CDP Commands – Instructor Version 2500
Objective
•
Use CDP commands to obtain information about neighboring networks and devices.
•
Display information on how CDP is configured for its advertisement and discovery frame
transmission.
•
Display CDP updates received on the local router.
Background/Preparation
CDP discovers and shows information about directly connected Cisco devices, including routers and
switches. CDP is a Cisco proprietary protocol that runs at the data link layer of the OSI model. The
data link layer is Layer 2 of the OSI model. This allows devices that may be running different network
Layer 3 protocols, such as IP or IPX, to learn about each other. CDP begins automatically upon a
device system startup. CDP may be enabled globally using the cdp run command. It may be
enabled on any interface as required using the cdp enable command. CDP is enabled on all
interfaces by default. Using the command show cdp interface gathers the information that CDP
uses for its advertisement and discovery frame transmission. Use show cdp neighbors and show
cdp neighbors detail to display the CDP updates received on the local router.
Cable a network similar to the one in the diagram. Any router that meets the interface requirements
may be used. Possible routers include 800, 1600, 1700, 2500, 2600 routers, or a combination. Refer
to the chart at the end of the lab to correctly identify the interface identifiers to be used based on the
equipment in the lab. The configuration output used in this lab is produced from 1721 series routers.
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CCNA 2: Routers and Routing Basics v 3.1 - Lab 4.1.6
Copyright  2003, Cisco Systems, Inc.
Any other router used may produce slightly different output. The following steps are intended to be
executed on each router unless specifically instructed otherwise.
Start a HyperTerminal session as performed in the Establishing a HyperTerminal session lab.
Note: Go to the erase and reload instructions at the end of this lab. Perform those steps on all
routers in this lab assignment before continuing.
Step 1 Log on to Router 1 (GAD)
Step 2 Configure the routers
a. Configure the routers according to the information in the table above in order for CDP to be able
to collect information about them. Refer to prior labs on configuring serial and Ethernet interfaces
and making changes to configurations if you need help.
Note: Do not use the no shutdown command on either of the router interfaces at this time.
b. What is the clock rate to be set to and which interface is it set on?
The clock rate is set to 56000 and the interface is Interface Serial 0 for this topology.
Step 3 Gather information about the router interfaces
a. Enter show interface command at either the user EXEC or the privileged EXEC router
prompt.
Document the following information about the router:
b. What is the name of the router? GAD>
c.
List operational status of each interface.
Interface
BRI0
BRI0:1
BRI0:2
Ethernet 0
Serial 0
Serial 1
Interface Up or Down?
(Carrier Detect Signal)
Administratively Down
Administratively Down
Administratively Down
Administratively Down
Administratively Down
Administratively Down
Line Protocol Up/Down?
(Keep Alives Being received)
Down
Down
Down
Down
Down
Down
Step 4 Enable the interfaces on Router 1 (GAD)
Router(config)#interface serial 0
Router(config-if)#no shutdown
Router(config-if)#exit
Router(config)#interface FastEthernet 0
Router(config-if)#no shutdown
Router(config-if)#exit
Router(config)#exit
Step 5 Gather information about the router interfaces
a. Enter show interface command at either the user EXEC or the privileged EXEC router
prompt.
b. Document the following information about the router:
c.
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What is the name of the router? GAD>
CCNA 2: Routers and Routing Basics v 3.1 - Lab 4.1.6
Copyright  2003, Cisco Systems, Inc.
d. List operational status of each interface:
Interface Up or Down?
(Carrier Detect Signal)
up
up
up
up
up
up
Interface
BRI0
BRI0:1
BRI0:2
Ethernet 0
Serial 0
Serial 1
Line Protocol Up/Down?
(Keep Alives Being received)
up
up
up
up
up
up
Step 6 Display the values of the CDP timers, the interface status, and encapsulation used
a. Enter show cdp interface command at the router prompt.
b. How often is the router sending CDP packets? 60 seconds
c.
What is the holdtime value? 180 seconds
d. Global CDP settings can be seen using the show cdp command by itself.
e. What information is not shown in the show cdp command? The status of the router interface.
Step 7 Display the CDP updates received on the local router
a. Enter show cdp neighbors command at the router prompt.
b. Fill in the following table:
Device and Port ID
Local Interface
Hold Time
Capability
Platform
There will not be any CDP entries as the serial line is down.
Step 8 Enable serial 0 interface on Router 2 (BHM)
a. Enter the no shutdown command on the serial 0 interface of Router 2. Return to Router 1 and
repeat Step 4. Notice how the router now appears in the cdp neighbor command display.
Step 9 Display details about CDP updates received on the local router
a. Enter show cdp neighbors detail from the router prompt.
b. Fill in the following table:
Information Gathered
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Device 1
Neighbor device name
BHM
Neighbor device type
Router
Interface attached to your router
Serial0
Port ID of your router that the neighbor is on
Serial0
Port ID of neighbor router that your router is on
Serial0
IOS version of neighbor router
12.0(5.3)
CCNA 2: Routers and Routing Basics v 3.1 - Lab 4.1.6
Copyright  2003, Cisco Systems, Inc.
Step 10 Observe CDP packets being sent and received on the router
a. Enter the debug cdp packets command from the privileged EXEC mode.
b. What is the output? (Wait for at least two minutes)
GAD#debug cdp packets
CDP packet info debugging is on
GAD#
6d12h: CDP-PA: Packet received from BHM on interface Serial0
6d12h: **Entry found in cache**
6d12h: CDP-PA: version 2 packet sent out on Ethernet0
6d12h: CDP-PA: version 2 packet sent out on Serial0
6d12h: CDP-PA: Packet received from Switch on interface Ethernet0
6d12h: **Entry found in cache**
6d12h: CDP-PA: Packet received from BHM on interface Serial0
6d12h: **Entry found in cache**
6d12h: CDP-PA: version 2 packet sent out on Ethernet0
6d12h: CDP-PA: version 2 packet sent out on Serial0
6d12h: CDP-PA: Packet received from Switch on interface Ethernet0
6d12h: **Entry found in cache**
c.
After observing the output enter the undebug all command to stop debugging activity.
Step 11 Observe CDP packet traffic
a. Enter the following commands at the privileged EXEC mode prompt and record the results.
b. show cdp traffic
GAD#show cdp traffic
CDP counters :
Total packets output: 112, Input: 102
Hdr syntax: 0, Chksum error: 0, Encaps failed: 0
No memory: 0, Invalid packet: 0, Fragmented: 0
CDP version 1 advertisements output: 0, Input: 0
CDP version 2 advertisements output: 112, Input: 102
c.
clear cdp counters
(no output for this command)
d. show cdp traffic
GAD#show cdp traffic
CDP counters :
Total packets output: 0, Input: 0
Hdr syntax: 0, Chksum error: 0, Encaps failed: 0
No memory: 0, Invalid packet: 0, Fragmented: 0
CDP version 1 advertisements output: 0, Input: 0
CDP version 2 advertisements output: 0, Input: 0
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Copyright  2003, Cisco Systems, Inc.
Erasing and reloading the router
Enter into the privileged EXEC mode by typing enable.
If prompted for a password, enter class. If “class” does not work, ask the instructor for assistance.
Router>enable
At the privileged EXEC mode, enter the command erase startup-config.
Router#erase startup-config
The responding line prompt will be:
Erasing the nvram filesystem will remove all files! Continue?
[confirm]
Press Enter to confirm.
The response should be:
Erase of nvram: complete
Now at the privileged EXEC mode, enter the command reload.
Router(config)#reloadRouter#reload
The responding line prompt will be:
System configuration has been modified. Save? [yes/no]:
Type n and then press Enter.
The responding line prompt will be:
Proceed with reload? [confirm]
Press Enter to confirm.
In the first line of the response will be:
Reload requested by console.
After the router has reloaded the line prompt will be:
Would you like to enter the initial configuration dialog? [yes/no]:
Type n and then press Enter.
The responding line prompt will be:
Press RETURN to get started!
Press Enter.
The router is ready for the assigned lab to be performed.
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Router Interface Summary
Router
Ethernet
Ethernet
Serial
Serial
Interface
Model
Interface #1
Interface #2
Interface #1
Interface #2
#5
800 (806)
Ethernet 0 (E0)
Ethernet 1 (E1)
1600
Ethernet 0 (E0)
Ethernet 1 (E1)
Serial 0 (S0)
Serial 1 (S1)
1700
FastEthernet 0 (FA0)
FastEthernet 1 (FA1)
Serial 0 (S0)
Serial 1 (S1)
2500
Ethernet 0 (E0)
Ethernet 1 (E1)
Serial 0 (S0)
Serial 1 (S1)
2600
FastEthernet 0/0
FastEthernet 0/1 (FA0/1) Serial 0/0 (S0/0)
Serial 0/1
(FA0/0)
(S0/1)
In order to find out exactly how the router is configured, look at the interfaces. This will identify the type of router
as well as how many interfaces the router has. There is no way to effectively list all of the combinations of
configurations for each router class. What is provided are the identifiers for the possible combinations of interfaces
in the device. This interface chart does not include any other type of interface even though a specific router may
contain one. An example of this might be an ISDN BRI interface. The string in parenthesis is the legal abbreviation
that can be used in IOS command to represent the interface.
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Copyright  2003, Cisco Systems, Inc.
Router#show interfaces
BRI0 is administratively down, line protocol is down
Hardware is BRI
MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/0/16 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
0 packets output, 0 bytes, 0 underruns
0 output errors, 0 collisions, 5 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
BRI0:1 is administratively down, line protocol is down
Hardware is BRI
MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set
Keepalive set (10 sec)
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/0/16 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
0 packets output, 0 bytes, 0 underruns
0 output errors, 0 collisions, 5 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
BRI0:2 is administratively down, line protocol is down
Hardware is BRI
MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set
Keepalive set (10 sec)
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/0/16 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
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CCNA 2: Routers and Routing Basics v 3.1 - Lab 4.1.6
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Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
0 packets output, 0 bytes, 0 underruns
0 output errors, 0 collisions, 5 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
Ethernet0 is administratively down, line protocol is down
Hardware is Lance, address is 00e0.1ed1.a859 (bia 00e0.1ed1.a859)
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:03:07, output 00:03:08, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue :0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
9 packets input, 5562 bytes, 0 no buffer
Received 9 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 input packets with dribble condition detected
33 packets output, 7056 bytes, 0 underruns
0 output errors, 0 collisions, 3 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
Serial0 is administratively down, line protocol is down
Hardware is HD64570
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set
Keepalive set (10 sec)
Last input never, output 00:03:20, output hang never
Last clearing of "show interface" counters 00:03:20
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue :0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
5 packets output, 859 bytes, 0 underruns
0 output errors, 0 collisions, 2 interface resets
0 output buffer failures, 0 output buffers swapped out
2 carrier transitions
DCD=down DSR=down DTR=up RTS=up CTS=down
Serial1 is administratively down, line protocol is down
Hardware is HD64570
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set
Keepalive set (10 sec)
Last input never, output 00:03:52, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
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Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/2/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
6 packets output, 132 bytes, 0 underruns
0 output errors, 0 collisions, 3 interface resets
0 output buffer failures, 0 output buffers swapped out
6 carrier transitions
DCD=up DSR=up DTR=down RTS=down CTS=up
GAD#show cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater
Device ID
Switch
Local Intrfce
Eth 0
Holdtme
149
Capability
T S
Platform Port ID
WS-C2950-1Fas 0/2
GAD#show cdp neighbors detail
------------------------Device ID: BHM
Entry address(es):
IP address: 172.17.0.2
Platform: cisco 2500, Capabilities: Router
Interface: Serial0, Port ID (outgoing port): Serial1
Holdtime : 136 sec
Version :
Cisco Internetwork Operating System Software
IOS (tm) 2500 Software (C2500-I-L), Version 12.1(18), RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2002 by cisco Systems, Inc.
Compiled Mon 02-Dec-02 23:45 by kellythw
advertisement version: 2
GAD#debug cdp packets
CDP packet info debugging is on
GAD#
6d12h: CDP-PA: Packet received from BHM on interface Serial0
6d12h: **Entry found in cache**
6d12h: CDP-PA: version 2 packet sent out on Ethernet0
6d12h: CDP-PA: version 2 packet sent out on Serial0
6d12h: **Entry found in cache**
6d12h: CDP-PA: Packet received from BHM on interface Serial0
6d12h: **Entry found in cache**
6d12h: CDP-PA: version 2 packet sent out on Ethernet0
6d12h: CDP-PA: version 2 packet sent out on Serial0
6d12h: **Entry found in cache**
GAD#show cdp traffic
CDP counters :
Total packets output: 112, Input: 102
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Copyright  2003, Cisco Systems, Inc.
Hdr syntax: 0, Chksum error: 0, Encaps failed: 0
No memory: 0, Invalid packet: 0, Fragmented: 0
CDP version 1 advertisements output: 0, Input: 0
CDP version 2 advertisements output: 112, Input: 102
GAD#clear cdp counters
GAD#show cdp traffic
CDP counters :
Total packets output: 0, Input: 0
Hdr syntax: 0, Chksum error: 0, Encaps failed: 0
No memory: 0, Invalid packet: 0, Fragmented: 0
CDP version 1 advertisements output: 0, Input: 0
CDP version 2 advertisements output: 0, Input: 0
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GAD#show running-config
Building configuration...
Current configuration : 567 bytes
!
version 12.1
no service single-slot-reload-enable
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname GAD
!
enable secret 5 $1$tw1P$Jvm9ZKx.DcaUNpul093T.1
enable password cisco
!
!
ip subnet-zero
!
!
interface Ethernet0
ip address 172.16.0.1 255.255.255.0
!
interface Serial0
ip address 172.17.0.1 255.255.255.0
no fair-queue
clockrate 56000
!
interface Serial1
no ip address
!
ip classless
ip http server
!
!
line con 0
password cisco
login
line aux 0
line vty 0 4
password cisco
login
!
end
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CCNA 2: Routers and Routing Basics v 3.1 - Lab 4.1.6
Copyright  2003, Cisco Systems, Inc.
Lab 4.1.6 Using CDP Commands – Instructor Version 2600
Objective
•
Use CDP commands to obtain information about neighboring networks and devices.
•
Display information on how CDP is configured for its advertisement and discovery frame
transmission.
•
Display CDP updates received on the local router.
Background/Preparation
CDP discovers and shows information about directly connected Cisco devices, including routers and
switches. CDP is a Cisco proprietary protocol that runs at the data link layer of the OSI model. The
data link layer is Layer 2 of the OSI model. This allows devices that may be running different network
Layer 3 protocols, such as IP or IPX, to learn about each other. CDP begins automatically upon a
device system startup. CDP may be enabled globally using the cdp run command. It may be
enabled on any interface as required using the cdp enable command. CDP is enabled on all
interfaces by default. Using the command show cdp interface gathers the information that CDP
uses for its advertisement and discovery frame transmission. Use show cdp neighbors and show
cdp neighbors detail to display the CDP updates received on the local router.
Cable a network similar to the one in the diagram. Any router that meets the interface requirements
may be used. Possible routers include 800, 1600, 1700, 2500, 2600 routers, or a combination. Refer
to the chart at the end of the lab to correctly identify the interface identifiers to be used based on the
equipment in the lab. The configuration output used in this lab is produced from 1721 series routers.
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CCNA 2: Routers and Routing Basics v 3.1 - Lab 4.1.6
Copyright  2003, Cisco Systems, Inc.
Any other router used may produce slightly different output. The following steps are intended to be
executed on each router unless specifically instructed otherwise.
Start a HyperTerminal session as performed in the Establishing a HyperTerminal session lab.
Note: Go to the erase and reload instructions at the end of this lab. Perform those steps on all
routers in this lab assignment before continuing.
Step 1 Log on to Router 1 (GAD)
Step 2 Configure the routers
a. Configure the routers according to the information in the table above in order for CDP to be able
to collect information about them. Refer to prior labs on configuring serial and Ethernet interfaces
and making changes to configurations if you need help.
Note: Do not use the no shutdown command on either of the router interfaces at this time.
b. What is the clock rate to be set to and which interface is it set on? 56000
Step 3 Gather information about the router interfaces
a. Enter show interface command at either the user EXEC or the privileged EXEC router
prompt.
Document the following information about the router:
b. What is the name of the router? GAD
c.
List operational status of each interface.
Interface
FastEthernet 0/0
FastEthernet 0/1
Serial 0/0
Serial 0/1
Interface Up or Down?
(Carrier Detect Signal)
Administratively down
Administratively down
Administratively down
Administratively down
Line Protocol Up/Down?
(Keep Alives Being received)
Down
Down
Down
Down
Step 4 Enable the interfaces on Router 1 (GAD)
Router(config)#interface serial 0/0
Router(config-if)#no shutdown
Router(config-if)#exit
Router(config)#interface FastEthernet 0/0
Router(config-if)#no shutdown
Router(config-if)#exit
Router(config)#exit
Step 5 Gather information about the router interfaces
a. Enter show interface command at either the user EXEC or the privileged EXEC router
prompt.
b. Document the following information about the router:
c.
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CCNA 2: Routers and Routing Basics v 3.1 - Lab 4.1.6
Copyright  2003, Cisco Systems, Inc.
d. List operational status of each interface:
Interface Up or Down?
(Carrier Detect Signal)
up
up
up
up
Interface
FastEthernet 0/0
FastEthernet 0/1
Serial 0/0
Serial 0/1
Line Protocol Up/Down?
(Keep Alives Being received)
up
up
up
up
Step 6 Display the values of the CDP timers, the interface status, and encapsulation used
a. Enter show cdp interface command at the router prompt.
b. How often is the router sending CDP packets? 60 seconds
c.
What is the holdtime value? 180 seconds
d. Global CDP settings can be seen using the show cdp command by itself.
e. What information is not shown in the show cdp command? The status of the router interface
Step 7 Display the CDP updates received on the local router
a. Enter show cdp neighbors command at the router prompt.
b. Fill in the following table:
Device and Port ID
Local Interface
Hold Time
Capability
Platform
There will not be any entries as the serial line is down.
Step 8 Enable serial 0 interface on Router 2 (BHM)
a. Enter the no shutdown command on the serial 0 interface of Router 2. Return to Router 1 and
repeat Step 4. Notice how the router now appears in the cdp neighbor command display.
Step 9 Display details about CDP updates received on the local router
a. Enter show cdp neighbors detail from the router prompt.
b. Fill in the following table:
Information Gathered
Device 1
Neighbor device ID
BHM
Neighbor device capabilities
Router
Interface attached to your router
Serial0/0
Port ID of your router that the neighbor is on
Serial0/0
Port ID of neighbor router that your router is on Serial0/0
IOS version of neighbor router
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12.2(12h)
Copyright  2003, Cisco Systems, Inc.
Step 10 Observe CDP packets being sent and received on the router
a. Enter the debug cdp packets command from the privileged EXEC mode.
b. What is the output? (Wait for at least two minutes)
00:22:50: CDP-PA: version 2 packet sent out on FastEthernet0/0
00:22:50: CDP-PA: version 2 packet sent out on Serial0/0
00:22:53: CDP-PA: Packet received from Router on interface Serial0/0
00:22:53: **Entry found in cache**
00:22:57: CDP-PA: Packet received from Switch on interface
FastEthernet0/0
00:22:57: **Entry found in cache**
00:23:50: CDP-PA: version 2 packet sent out on FastEthernet0/0
00:23:50: CDP-PA: version 2 packet sent out on Serial0/0
00:23:53: CDP-PA: Packet received from Router on interface Serial0/0
00:23:53: **Entry found in cache**
00:23:57: CDP-PA: Packet received from Switch on interface
FastEthernet0/0
000:23:57: **Entry found in cache**
c.
After observing the output enter the undebug all command to stop debugging activity.
Step 11 Observe CDP packet traffic
a. Enter the following commands at the privileged EXEC mode prompt and record the results.
b. show cdp traffic
Router#show cdp traffic
CDP counters :
Total packets output: 102, Input: 97
Hdr syntax: 0, Chksum error: 0, Encaps failed: 3
No memory: 0, Invalid packet: 0, Fragmented: 0
CDP version 1 advertisements output: 0, Input: 0
CDP version 2 advertisements output: 102, Input: 97
c.
clear cdp counters
(no output for this command)
d. show cdp traffic
Router#show cdp traffic
CDP counters :
Total packets output: 0, Input: 0
Hdr syntax: 0, Chksum error: 0, Encaps failed: 0
No memory: 0, Invalid packet: 0, Fragmented: 0
CDP version 1 advertisements output: 0, Input: 0
CDP version 2 advertisements output: 0, Input:
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CCNA 2: Routers and Routing Basics v 3.1 - Lab 4.1.6
Copyright  2003, Cisco Systems, Inc.
Erasing and reloading the router
Enter into the privileged EXEC mode by typing enable.
If prompted for a password, enter class. If “class” does not work, ask the instructor for assistance.
Router>enable
At the privileged EXEC mode, enter the command erase startup-config.
Router#erase startup-config
The responding line prompt will be:
Erasing the nvram filesystem will remove all files! Continue?
[confirm]
Press Enter to confirm.
The response should be:
Erase of nvram: complete
Now at the privileged EXEC mode, enter the command reload.
Router(config)#reloadRouter#reload
The responding line prompt will be:
System configuration has been modified. Save? [yes/no]:
Type n and then press Enter.
The responding line prompt will be:
Proceed with reload? [confirm]
Press Enter to confirm.
In the first line of the response will be:
Reload requested by console.
After the router has reloaded the line prompt will be:
Would you like to enter the initial configuration dialog? [yes/no]:
Type n and then press Enter.
The responding line prompt will be:
Press RETURN to get started!
Press Enter.
The router is ready for the assigned lab to be performed.
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CCNA 2: Routers and Routing Basics v 3.1 - Lab 4.1.6
Copyright  2003, Cisco Systems, Inc.
Router Interface Summary
Router
Ethernet
Ethernet
Serial
Serial
Interface
Model
Interface #1
Interface #2
Interface #1
Interface #2
#5
800 (806)
Ethernet 0 (E0)
Ethernet 1 (E1)
1600
Ethernet 0 (E0)
Ethernet 1 (E1)
Serial 0 (S0)
Serial 1 (S1)
1700
FastEthernet 0 (FA0)
FastEthernet 1 (FA1)
Serial 0 (S0)
Serial 1 (S1)
2500
Ethernet 0 (E0)
Ethernet 1 (E1)
Serial 0 (S0)
Serial 1 (S1)
2600
FastEthernet 0/0
FastEthernet 0/1 (FA0/1) Serial 0/0 (S0/0)
Serial 0/1
(FA0/0)
(S0/1)
In order to find out exactly how the router is configured, look at the interfaces. This will identify the type of router
as well as how many interfaces the router has. There is no way to effectively list all of the combinations of
configurations for each router class. What is provided are the identifiers for the possible combinations of interfaces
in the device. This interface chart does not include any other type of interface even though a specific router may
contain one. An example of this might be an ISDN BRI interface. The string in parenthesis is the legal abbreviation
that can be used in IOS command to represent the interface.
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CCNA 2: Routers and Routing Basics v 3.1 - Lab 4.1.6
Copyright  2003, Cisco Systems, Inc.
Router#show running-config
Building configuration...
Current configuration : 547 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Router
!
!
ip subnet-zero
!
!
!
call rsvp-sync
!
!
!
!
!
!
!
!
interface FastEthernet0/0
no ip address
duplex auto
speed auto
!
interface Serial0/0
no ip address
no fair-queue
clockrate 56000
!
interface FastEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/1
no ip address
shutdown
!
ip classless
ip http server
!
!
dial-peer cor custom
!
!
!
!
line con 0
line aux 0
line vty 0 4
!
end
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CCNA 2: Routers and Routing Basics v 3.1 - Lab 4.1.6
Copyright  2003, Cisco Systems, Inc.
Router#show cdp
Global CDP information:
Sending CDP packets every 60 seconds
Sending a holdtime value of 180 seconds
Sending CDPv2 advertisements is enabled
Router#
Router#show cdp inter
Router#show cdp interface
FastEthernet0/0 is up, line protocol is up
Encapsulation ARPA
Sending CDP packets every 60 seconds
Holdtime is 180 seconds
Serial0/0 is up, line protocol is up
Encapsulation HDLC
Sending CDP packets every 60 seconds
Holdtime is 180 seconds
FastEthernet0/1 is administratively down, line protocol is down
Encapsulation ARPA
Sending CDP packets every 60 seconds
Holdtime is 180 seconds
Serial0/1 is administratively down, line protocol is down
Encapsulation HDLC
Sending CDP packets every 60 seconds
Holdtime is 180 seconds
Router#
Router#sho cdp nei
Router#sho cdp neighbors det
Router#sho cdp neighbors detail
------------------------Device ID: Router
Entry address(es):
Platform: cisco 2621, Capabilities: Router
Interface: Serial0/0, Port ID (outgoing port): Serial0/0
Holdtime : 137 sec
Version :
Cisco Internetwork Operating System Software
IOS (tm) C2600 Software (C2600-IS-M), Version 12.2(12), RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2002 by cisco Systems, Inc.
Compiled Wed 21-Aug-02 03:01 by pwade
Router#show cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater
Device ID
Router
Local Intrfce
Ser 0/0
Holdtme
129
Capability
R
Platform
2621
Port ID
Ser 0/0
Router#
Router#show cdp traffic
CDP counters :
Total packets output: 12, Input: 11
Hdr syntax: 0, Chksum error: 0, Encaps failed: 0
No memory: 0, Invalid packet: 0, Fragmented: 0
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CCNA 2: Routers and Routing Basics v 3.1 - Lab 4.1.6
Copyright  2003, Cisco Systems, Inc.
CDP version 1 advertisements output: 0, Input: 0
CDP version 2 advertisements output: 12, Input: 11
Router#
Debug Output
00:22:50: CDP-PA:
00:22:50: CDP-PA:
00:22:53: CDP-PA:
00:22:53: **Entry
00:22:57: CDP-PA:
00:22:57: **Entry
00:23:50: CDP-PA:
00:23:50: CDP-PA:
00:23:53: CDP-PA:
00:23:53: **Entry
00:23:57: CDP-PA:
00:23:57: **Entry
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version 2 packet sent out on FastEthernet0/0
version 2 packet sent out on Serial0/0
Packet received from Router on interface Serial0/0
found in cache**
Packet received from Switch on interface FastEthernet0/0
found in cache**
version 2 packet sent out on FastEthernet0/0
version 2 packet sent out on Serial0/0
Packet received from Router on interface Serial0/0
found in cache**
Packet received from Switch on interface FastEthernet0/0
found in cache**
CCNA 2: Routers and Routing Basics v 3.1 - Lab 4.1.6
Copyright  2003, Cisco Systems, Inc.