This sample configuration statically routes both IP and IPX over a partially-meshed frame relay network using point-to-point subinterfaces. Static IP routes and static IPX routes and services must be manually created on every router for each desired destination. For smaller networks, static routing may suffice. However, for larger networks, manually maintaining static routing tables on every router can be an undesirable administrative chore.

Get A Dynamically Routed IP and IPX Configuration (recommended)
Faxback Doc #0523

Subinterfaces logically divide a single, physical interface into separate, virtual point-to-point interfaces. A single frame relay interface connecting to multiple destinations can now be treated as a collection of point-to-point network segments. Each subinterface segment requires a unique IP subnet and IPX network number. Fortunately, unnumbered IP segments can be used to alleviate the burden of designing the additional IP subnets.

In general, it is good practice to use subinterfaces for partially-meshed frame relay networks. A frame relay network designed with subinterfaces scales much easier to future expansion. Referring to the example, subinterfaces allow routing updates to exchange between Boston and Chicago through Atlanta. Without subinterfaces, Boston is unable to receive routing updates from Chicago and vice versa creating a condition known as split-horizon.

Info On Subinterfaces Faxback Doc #subifs

Info On IP Unnumbered Faxback Doc #ip_unnum

Before You Begin

Get The IOS Frame Relay Command Glossary. Faxback Doc #0550 Detailed descriptions of all IOS commands used in frame relay configurations. Also provides links to the IOS Command Reference if more information is required

Get The IOS Command Line Interface Tutorial Faxback Doc #ios_tutorial Instructions on configuring an IOS router using the command line interface

Note: Commands followed by a <*> are on by default and do not have to be configured. The "!" marks that appear in the configuration are automatically entered by the router and function as line separators for easier reading.

Atlanta Router Configuration
In IOS "show running-config" format

version 11.2 <*>
service udp-small-servers <*>
service tcp-small-servers <*>
!
hostname Atlanta
!
enable secret cisco
!
ip subnet-zero
no ip domain-lookup
ipx routing 0000.0caa.1111
!
interface Ethernet0
 ip address 10.1.1.1 255.0.0.0
 ipx network 100 encapsulation SAP
 ipx network 101 encapsulation NOVELL-ETHER secondary
!
interface Serial0
 no ip address <*>
 encapsulation frame-relay
 frame-relay lmi-type ansi
!
interface Serial0.16 point-to-point
 description Frame Relay to Boston
 ip unnumbered Ethernet0
 ipx network AAAA
 ipx sap-interval 0
 frame-relay interface-dlci 16
!
interface Serial0.17 point-to-point
 description Frame Relay to Chicago
 ip unnumbered Ethernet0
 ipx network BBBB
 ipx sap-interval 0
 frame-relay interface-dlci 17
!
ip http server
ip classless
ip route 20.0.0.0 255.0.0.0 Serial0.16
ip route 30.0.0.0 255.0.0.0 Serial0.17
!
ipx route 200 AAAA.0000.0cbb.2222
ipx route 300 BBBB.0000.0ccc.3333
ipx route 2000 AAAA.0000.0cbb.2222
ipx route 3000 BBBB.0000.0ccc.3333
!
ipx router rip
 no network AAAA
 no network BBBB
!
ipx sap 4 BostonFS 2000.0000.0000.0001 451 2
ipx sap 4 ChicagoFS 3000.0000.0000.0001 451 2
!
line con 0
 password console
 login
line aux 0 <*>
line vty 0 4
 password telnet
 login <*>
!
end <*>

Boston Router Configuration
In IOS "show running-config" format

version 11.2 <*>
service udp-small-servers <*>
service tcp-small-servers <*>
!
hostname Boston
!
enable secret cisco
!
ip subnet-zero
no ip domain-lookup
ipx routing 0000.0cbb.2222
!
interface Ethernet0
 ip address 20.1.1.1 255.0.0.0
 ipx network 200
!
interface Serial0
 no ip address <*>
 encapsulation frame-relay
!
interface Serial0.16 point-to-point
 description Frame Relay to Atlanta
 ip unnumbered Ethernet0
 ipx network AAAA
 ipx sap-interval 0
 frame-relay interface-dlci 16
!
ip http server
ip classless
ip route 0.0.0.0 0.0.0.0 Serial0.16
!
ipx route 100 AAAA.0000.0caa.1111
ipx route 300 AAAA.0000.0caa.1111
ipx route 1000 AAAA.0000.0caa.1111
ipx route 3000 AAAA.0000.0caa.1111
!
ipx router rip
 no network AAAA
!
ipx sap 4 AtlantaFS 1000.0000.0000.0001 451 2
ipx sap 4 ChicagoFS 3000.0000.0000.0001 451 2
!
line con 0
 password console
 login
line aux 0 <*>
line vty 0 4
 password telnet
 login <*>
!
end <*>

Chicago Router Configuration
In IOS "show running-config" format

version 11.1 <*>
service udp-small-servers <*>
service tcp-small-servers <*>
!
hostname Chicago
!
enable secret cisco
!
ip subnet-zero
no ip domain-lookup
ipx routing 0000.0ccc.3333
!
interface Ethernet0
 ip address 30.1.1.1 255.0.0.0
 ipx network 300
!
interface Serial0
 no ip address <*>
 encapsulation frame-relay
 frame-relay lmi-type ansi
!
interface Serial0.16 point-to-point
 description Frame Relay to Atlanta
 ip unnumbered Ethernet0
 ipx network BBBB
 ipx sap-interval 0
 frame-relay interface-dlci 16
!
ip http server
ip classless
ip route 0.0.0.0 0.0.0.0 Serial0.16
!
ipx route 100 BBBB.0000.0caa.1111
ipx route 200 BBBB.0000.0caa.1111
ipx route 1000 BBBB.0000.0caa.1111
ipx route 2000 BBBB.0000.0caa.1111
!
ipx router rip
 no network BBBB
!
ipx sap 4 AtlantaFS 1000.0000.0000.0001 451 2
ipx sap 4 BostonFS 2000.0000.0000.0001 451 2
!
line con 0
 password console
 login
line aux 0 <*>
line vty 0 4
 password telnet
 login <*>
!
end <*>

After You've Tried

You've tried the configuration and it doesn't work. Help is available!

Get IOS Router Frame Relay Troubleshooting Assistance Faxback Doc #fr_ts

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