Main interface is always in multipoint mode.
Sub-interface type must be specified (multipoint or point-to-point).
In this example
Hub & Spoke architecture with dynamic mapping (inarp) enabled.
The problem
In hub & spoke topologies, with dynamic mapping, spokes can’t see each other through the hub.
Configuration
R1 is the hub, r2 and r3 are the spokes.
Inarp is enabled by default.
r1#sh run int s1/0
Building configuration...
Current configuration : 137 bytes
!
interface Serial1/0
ip address 150.123.0.1
255.255.255.0
encapsulation frame-relay
serial restart-delay 0
no clns route-cache
end
r2#sh run int s1/0
Building configuration...
Current configuration : 137 bytes
!
interface Serial1/0
ip address 150.123.0.2
255.255.255.0
encapsulation frame-relay
serial restart-delay 0
no clns route-cache
end
r3#sh run int s1/0
Building configuration...
Current configuration : 137 bytes
!
interface Serial1/0
ip address 150.123.0.3
255.255.255.0
encapsulation frame-relay
serial restart-delay 0
no clns route-cache
end
Using inarp dynamic mapping, r1 sees r2 and r3:
r1#show frame-relay map
Serial1/0 (up): ip 150.123.0.2 dlci 102(0x66,0x1860), dynamic,
broadcast,
CISCO, status
defined, active
Serial1/0 (up): ip 150.123.0.3 dlci 103(0x67,0x1870), dynamic,
broadcast,
CISCO, status
defined, active
r1#
but r2 and r3 can’t see each other:
r2#show frame-relay map
Serial1/0 (up): ip 150.123.0.1 dlci 201(0xC9,0x3090), dynamic,
broadcast,
CISCO, status
defined, active
r3#sh frame-relay map
Serial1/0 (up): ip 150.123.0.1 dlci 301(0x12D,0x48D0), dynamic,
broadcast,
CISCO, status
defined, active
Solution
To enable communication between the spokes, use "frame-relay map ip
"
r3#sh run int s1/0
Building configuration...
Current configuration : 173 bytes
!
interface Serial1/0
ip address 150.123.0.3
255.255.255.0
encapsulation frame-relay
serial restart-delay 0
frame-relay map ip 150.123.0.2 301
no clns route-cache
end
Do the same on r2.
Verification:
r3#sh frame-relay map
Serial1/0 (up): ip 150.123.0.2 dlci 301(0x12D,0x48D0), static,
CISCO, status
defined, active
Serial1/0 (up): ip 150.123.0.1 dlci 301(0x12D,0x48D0), dynamic,
broadcast,
CISCO, status
defined, active
r3#
Note that broadcast is not enabled on the static mapping. This is not a
problem because it is already enabled on the dlci through the dynamic mapping.
