Configure Interfaces
Configure two active interfaces on a Cisco IOS router.
Configure Router Interfaces
- Configuring a router interface includes issuing the following commands:
Router(config)# interface type-and-number
Router(config-if)# description description-text
Router(config-if)# ip address ipv4-address subnet-mask
Router(config-if)# ipv6 address ipv6-address/prefix-length
Router(config-if)# no shutdown
- It is a good practice to use the description command to add information about the network connected to the interface.
- The no shutdown command activates the interface.
Configure Router Interfaces Example
- The commands to configure interface G0/0/0 on R1 are shown here:
R1(config)# interface gigabitEthernet 0/0/0
R1(config-if)# description Link to LAN
R1(config-if)# ip address 192.168.10.1 255.255.255.0
R1(config-if)# ipv6 address 2001:db8:acad:10::1/64
R1(config-if)# no shutdown
R1(config-if)# exit
R1(config)#*Aug 1 01:43:53.435: %LINK-3-UPDOWN: Interface GigabitEthernet0/0/0, changed state to down The commands to configure interface G0/0/1 on R1 are shown here:
*Aug 1 01:43:56.447: %LINK-3-UPDOWN: Interface GigabitEthernet0/0/0, changed state to up
*Aug 1 01:43:57.447: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/0, changed state to upR1(config)# interface gigabitEthernet 0/0/1
R1(config-if)# description Link to R2
R1(config-if)# ip address 209.165.200.225 255.255.255.252
R1(config-if)# ipv6 address 2001:db8:feed:224::1/64
R1(config-if)# no shutdown
R1(config-if)# exit
R1(config)#*Aug 1 01:46:29.170: %LINK-3-UPDOWN: Interface GigabitEthernet0/0/1, changed state to down
*Aug 1 01:46:32.171: %LINK-3-UPDOWN: Interface GigabitEthernet0/0/1, changed state to up
*Aug 1 01:46:33.171: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/1, changed state to up
Verify Interface Configuration
- To verify interface configuration use the show ip interface brief and show ipv6 interface brief commands shown here:
Configure Verification Commands
The table summarizes show commands used to verify interface configuration.
| Commands | Description |
|---|---|
| show ip interface brief | Displays all interfaces, their IP addresses, and their current status. |
| show ipv6 interface brief | Displays all interfaces, their IPv6 addresses, and their current status. |
| show ip route | Displays the contents of the IPv4 routing table stored in RAM. |
| show ipv6 route | Displays the contents of the IPv6 routing table stored in RAM. |
| show interfaces | Displays statistics for all interfaces on the device. Only displays the IPv4 addressing information. |
| show ip interfaces | Displays the IPv4 statistics for all interfaces on a router. |
| show ipv6 interfaces | Displays the IPv6 statistics for all interfaces on a router. |
- View status of all interfaces with the show ip interface brief and show ipv6 interface brief commands, shown here:
- Display the contents of the IP routing tables with the show ip route and show ipv6 route commands as shown here:
- Display IPv4 statistics for router interfaces with the show ip interface command, as shown here:
- Display IPv6 statistics for router interfaces with the show ipv6 interface command shown here:
Other related topics
| Topic Title | Topic Objective |
|---|---|
| Configure Initial Router Settings | Configure initial settings on an IOS Cisco router. |
| Configure Interfaces | Configure two active interfaces on a Cisco IOS router. |
| Configure the Default Gateway | Configure devices to use the default gateway. |
Other useful information