Cisco 520-T1 Software Guide - Page 27

Example:, ip address ip-address mask, Configuration Example, Verifying Your Configuration

Page 27 highlights

Chapter 1 Basic Router Configuration Configuring Basic Parameters Perform these steps to configure a loopback interface, beginning in global configuration mode: Step 1 Command interface type number Step 2 Example: Router(config)# interface Loopback 0 Router(config-if)# ip address ip-address mask Example: Router(config-if)# ip address 10.108.1.1 255.255.255.0 Router(config-if)# Step 3 exit Example: Router(config-if)# exit Router(config)# Purpose Enters configuration mode for the loopback interface. Sets the IP address and subnet mask for the loopback interface. Exits configuration mode for the loopback interface and returns to global configuration mode. Configuration Example The loopback interface in this sample configuration is used to support Network Address Translation (NAT) on the virtual-template interface. This configuration example shows the loopback interface configured on the Fast Ethernet interface with an IP address of 200.200.100.1/24, which acts as a static IP address. The loopback interface points back to virtual-template1, which has a negotiated IP address. ! interface loopback 0 ip address 200.200.100.1 255.255.255.0 (static IP address) ip nat outside ! interface Virtual-Template1 ip unnumbered loopback0 no ip directed-broadcast ip nat outside ! Verifying Your Configuration To verify that you have properly configured the loopback interface, enter the show interface loopback command. You should see verification output similar to the following example. Router# show interface loopback 0 Loopback0 is up, line protocol is up Hardware is Loopback Internet address is 200.200.100.1/24 MTU 1514 bytes, BW 8000000 Kbit, DLY 5000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation LOOPBACK, loopback not set Last input never, output never, output hang never OL-14210-01 Cisco Secure Router 520 Series Software Configuration Guide 1-7

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162

1-7
Cisco Secure Router 520 Series Software Configuration Guide
OL-14210-01
Chapter 1
Basic Router Configuration
Configuring Basic Parameters
Perform these steps to configure a loopback interface, beginning in global configuration mode:
Configuration Example
The loopback interface in this sample configuration is used to support Network Address Translation
(NAT) on the virtual-template interface. This configuration example shows the loopback interface
configured on the Fast Ethernet interface with an IP address of 200.200.100.1/24, which acts as a static
IP address. The loopback interface points back to virtual-template1, which has a negotiated IP address.
!
interface loopback 0
ip address 200.200.100.1 255.255.255.0 (
static IP address
)
ip nat outside
!
interface Virtual-Template1
ip unnumbered loopback0
no ip directed-broadcast
ip nat outside
!
Verifying Your Configuration
To verify that you have properly configured the loopback interface, enter the
show interface loopback
command. You should see verification output similar to the following example.
Router#
show interface loopback 0
Loopback0 is up, line protocol is up
Hardware is Loopback
Internet address is 200.200.100.1/24
MTU 1514 bytes, BW 8000000 Kbit, DLY 5000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation LOOPBACK, loopback not set
Last input never, output never, output hang never
Command
Purpose
Step 1
interface
type number
Example:
Router(config)#
interface Loopback 0
Router(config-if)#
Enters configuration mode for the loopback
interface.
Step 2
ip address
ip-address mask
Example:
Router(config-if)#
ip address 10.108.1.1
255.255.255.0
Router(config-if)#
Sets the IP address and subnet mask for the
loopback interface.
Step 3
exit
Example:
Router(config-if)#
exit
Router(config)#
Exits configuration mode for the loopback
interface and returns to global configuration mode.