Task 1:
For reference information on configuring hostnames, please refer to:
Lab 35 Configuration and Verification Task 1
Task 2:
For reference information on configuring DCE clocking, please refer to:
Lab 57 Configuration and Verification Task 2
Lab 58 Configuration and Verification Task 2
For reference information on configuring IP interfaces, please refer to:
Lab 31 Configuration and Verification Task 3
Task 3:
Sw1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Sw1(config)#vlan 50
Sw1(config-vlan)#name NAT_VLAN
Sw1(config-vlan)#exit
Sw1(config)#int f0/2
Sw1(config-if)#switchport mode access
Sw1(config-if)#switchport access vlan 50
Sw1(config-if)#no shutdown
Sw1(config-if)#exit
Sw1(config)#line vty 0 15
Sw1(config-line)#password CISCO
Sw1(config-line)#login
Sw1(config-line)#end
Sw1#
Sw1#show vlan brief
| VLAN | Name | Status | Ports |
| —- | ——————————– | ——— | ——————————- |
| 1 | default | active | Fa0/1, Fa0/3, Fa0/4, Fa0/5 |
| Fa0/6, Fa0/7, Fa0/8, Fa0/9 | |||
| Fa0/10, Fa0/11, Fa0/12, Fa0/13 | |||
| Fa0/14, Fa0/15, Fa0/16, Fa0/17 | |||
| Fa0/18, Fa0/19, Fa0/20, Fa0/21 | |||
| Fa0/22, Fa0/23, Fa0/24, Gi0/1 | |||
| Gi0/2 | |||
| 50 | NAT_VLAN | active | Fa0/2 |
| 1002 | fddi-default | active | |
| 1003 | trcrf-default | active | |
| 1004 | fddinet-default | active | |
| 1005 | trbrf-default | active |
Task 4:
Sw1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Sw1(config)#int vlan 1
Sw1(config-if)#shutdown
Sw1(config-if)#exit
Sw1(config)#int vlan 50
Sw1(config-if)#no shutdown
Sw1(config-if)#ip address 10.2.2.4 255.255.255.224
Sw1(config-if)#exit
Sw1(config)#ip default-gateway 10.2.2.2
Sw1(config)#end
Sw1#
R3#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#int fa0/0
R3(config-if)#no shutdown
R3(config-if)#ip address 10.2.2.2 255.255.255.224
R3(config-if)#end
R3#
Task 5:
R1#ping 192.168.254.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.254.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/4/4 ms
R3#ping 192.168.254.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.254.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/4/4 ms
R3#ping 10.2.2.4
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.2.2.4, timeout is 2 seconds:
..!!!
Success rate is 60 percent (3/5), round-trip min/avg/max = 1/3/4 ms
Sw1#ping 10.2.2.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.2.2.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/4/8 ms
Sw1#ping 192.168.254.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.254.1, timeout is 2 seconds:
…..
Success rate is 0 percent (0/5)
Task 6:
R3#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#access-list 140 remark ‘Permit ICMP Traffic For NAT’
Sw1(config)#access-list 140 permit icmp 10.2.2.0 0.0.0.31 any
Sw1(config)#access-lis 140 permit tcp 10.2.2.0 0.0.0.31 any eq telnet
R3(config)#end
R3#
R3#show ip access-lists 140
Extended IP access list 140
10 permit icmp 10.2.2.0 0.0.0.31 any
20 permit tcp 10.2.2.0 0.0.0.31 any eq telnet
Task 7:
R3#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#int fa0/0
R3(config-if)#ip nat inside
R3(config-if)#exit
R3(config)#int s0/0
R3(config-if)#ip nat outside
R3(config-if)#exit
R3(config)#ip nat inside source list 140 interface serial 0/0 overload
R3(config)#end
R3#
| NOTE: Port Address Translation (or NAT Overload) is enabled by using the overload keyword in the ip nat inside souce list command. This allows the router to overload address translation to the specified interface or IP address. Do not forget to issue this keyword when configuring PAT. Otherwise, you will have created dynamic NAT and will run out of addresses after the very first translation. |
Task 8:
Perform a ping and then telnet from Sw1 and then disconnect from the telnet session.
Sw1#ping 192.168.254.1
Sw1#telnet 192.168.254.1
R3#
R3#show ip nat translations
Pro Inside global Inside local Outside local Outside global
tcp 192.168.254.2:11777 10.2.2.4:11777 192.168.254.1:23 192.168.254.1:23
icmp 192.168.254.2:4176 10.2.2.4:4176 192.168.254.1:4176 192.168.254.1:4176
icmp 192.168.254.2:4177 10.2.2.4:4177 192.168.254.1:4177 192.168.254.1:4177
icmp 192.168.254.2:4178 10.2.2.4:4178 192.168.254.1:4178 192.168.254.1:4178
icmp 192.168.254.2:4179 10.2.2.4:4179 192.168.254.1:4179 192.168.254.1:4179
icmp 192.168.254.2:4180 10.2.2.4:4180 192.168.254.1:4180 192.168.254.1:4180
| NOTE: Notice that there is only one translation for Telnet but there are five translations for Ping. This is because a dynamic translation is created for every ping packet sent. By default, Cisco routers and switches will send five ping packets. You can tell they are from the same ping because the port numbers are sequential.
Also, by using interface based PAT, R1 will see all packets (Ping and Telnet) being sourced from the Serial0/0 interface of R3. If we enabled the debug ip packet detail command on R1, we would see the following for Telnet:
*Mar 1 01:07:45.127: TCP src=23, dst=12289, seq=2994196370, ack=125681435, win=4085 ACK PSH *Mar 1 01:07:45.272: IP: tableid=0, s=192.168.254.2 (Serial0/0), d=192.168.254.1 (Serial0/0), routed via RIB
In a similar manner, we would also see the following for pings from Sw2:
*Mar 1 01:08:40.907: IP: s=192.168.254.2 (Serial0/0), d=192.168.254.1 (Serial0/0), len 100, rcvd 3 *Mar 1 01:08:40.907: ICMP type=8, code=0 *Mar 1 01:08:40.907: IP: tableid=0, s=192.168.254.1 (local), d=192.168.254.2 (Serial0/0), routed via FIB *Mar 1 01:08:40.907: IP: s=192.168.254.1 (local), d=192.168.254.2 (Serial0/0), len 100, sending *Mar 1 01:08:40.907: ICMP type=0, code=0
|
R#show ip nat statistics
Total active translations: 5 (0 static, 5 dynamic; 5 extended)
Outside interfaces:
Serial0/0
Inside interfaces:
FastEthernet0/0
Hits: 153 Misses: 23
Expired translations: 16
Dynamic mappings:
— Inside Source
[Id: 3] access-list 140 interface Serial0/0 refcount 5