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Cisco AS5350 and Cisco AS5400 Universal Gateway Software Configuration Guide
OL-3418-02 B0
Chapter 3
Basic Configuration Using the Command-Line Interface
Configuring Loopback Interfaces, Fast Ethernet Interfaces, and IP Route
Username: admin
Password:
AS5400#
Configuring Loopback Interfaces, Fast Ethernet Interfaces, and
IP Route
To commission a basic dial access service perform the following tasks:
•
Create two loopback interfaces.
•
Bring up the Fast Ethernet interface.
•
Add an IP route to the default gateway.
Step 1
Assign the IP addresses as in the following example, and create an IP route to the default gateway:
AS5400(config)# interface loopback 0
AS5400(config-if)# ip address 172.22.99.1 255.255.255.255
AS5400(config-if)# exit
AS5400(config)# interface loopback 1
AS5400(config-if)# ip address 172.22.90.1 255.255.255.0
AS5400(config-if)# exit
AS5400(config)# interface FastEthernet 0/0
AS5400(config-if)# ip address 172.28.186.55 255.255.255.240
AS5400(config-if)# no shutdown
AS5400(config-if)# exit
AS5400(config)# ip route 0.0.0.0 0.0.0.0 172.28.186.49
In this example:
•
Interface loopback 0—Identifies with a unique and stable IP address. One unique IP address from a
common block of addresses is assigned to each device in the IP network. This technique makes
security-filtering easy for the Network Operations Center (NOC). One class C subnet used for
device identification can support 254 distinct devices with unique loopback addresses.
•
Interface loopback 1—Hosts a pool of IP addresses for the remote nodes. In this way, one route,
instead of 254 routes, is summarized and propagated to the backbone. Pick the IP address for
loopback 1 from the range of addresses that you will assign to the local address pool.
Step 2
Verify that the Fast Ethernet interface is up. Ping the default gateway to verify this.
AS5400# ping 172.28.186.49
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.28.186.49, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 1/1/4 ms
This step verifies that you have IP connectivity with another device on the subnet. If the ping succeeds
to the default gateway, try pinging the DNS server in your backbone. Make sure that the backbone routers
are configured to get to the gateway; otherwise, the ping does not work. Configure the backbone routers
to support the routes to the networks you are using.
