Specifications
Configuring Asynchronous Lines and Interfaces
Configuration Examples for Asynchronous Interfaces and Lines
DC-42
Cisco IOS Dial Technologies Configuration Guide
Asynchronous Interface As the Only Network Interface Example
The following example shows how one of the asynchronous lines can be used as the only network
interface. The router is used primarily as a terminal server, but is at a remote location and dials in to the
central site for its only network connection.
ip default-gateway 10.11.12.2
interface ethernet 0
shutdown
interface async 1
async dynamic routing
ip tcp header-compression on
async default ip address 10.11.16.12
async mode dedicated
ip address 10.11.12.32 255.255.255.0
Routing on a Dedicated Dial-In Router Example
The following example shows how a router is set up as a dedicated dial-in router. Interfaces are
configured as IP unnumbered to conserve network resources, primarily IP addresses.
ip routing
interface ethernet 0
ip address 10.129.128.2 255.255.255.0
!
interface async 1
ip unnumbered ethernet 0
async dynamic routing
! The addresses assigned with SLIP or PPP EXEC commands are not used except
! to reply to BOOTP requests.
! Normally, the routers dialing in will have their own address and not use BOOTP at all.
async default ip address 10.11.11.254
!
interface async 2
ip unnumbered ethernet 0
async default ip address 10.11.12.16
ip tcp header-compression passive
async mode dedicated
!
! Run RIP on the asynchronous lines because few implementations of SLIP
! understand IGRP. Run IGRP on the Ethernet (and in the local network).
!
router igrp 110
network 10.11.12.0
! Send routes from the asynchronous lines on the production network.
redistribute RIP
! Do not send IGRP updates on the asynchronous interfaces.
passive-interface async 1
!
router RIP
network 10.11.12.0
redistribute igrp
passive-interface ethernet 0
! Consider filtering everything except a default route from the routing
! updates sent on the (slow) asynchronous lines.
distribute-list 1 out
ip unnumbered async 2
async dynamic routing