Lab 7. Frame Relay (Point-to-Point Subinterface + Main Interface using Inverse-ARP)

Below is configuration for frame relay (point-to-point subinterface + main interface using Inverse-ARP)

R1#sh run | sec Serial0/0
interface Serial0/0
no ip address
encapsulation frame-relay

interface Serial0/0.1 point-to-point
ip address 12.12.12.1 255.255.255.0
frame-relay interface-dlci 102

R2#sh run | sec Serial0/0
interface Serial0/0
no ip address
encapsulation frame-relay

interface Serial0/0.1 point-to-point
ip address 12.12.12.2 255.255.255.0
frame-relay interface-dlci 201

R1 & R2 is still using subinterface point-to-point. Let’s change R2 using main interface: Inverse-ARP.

R2(config)#no int s0/0.1
Not all config may be removed and may reappear after reactivating the sub-interface
R2(config)#do sh ip int brie
Interface            IP-Address OK? Method   Status                         Protocol
FastEthernet0/0 unassigned   YES NVRAM administratively down down
Serial0/0            unassigned  YES NVRAM  up                               up
Serial0/0.1         unassigned  YES NVRAM  deleted                       down
FastEthernet0/1 unassigned  YES NVRAM  administratively down  down
Serial0/1            unassigned  YES NVRAM administratively down  down
R2(config)#do sh run int s0/0
Building configuration...
Current configuration : 89 bytes
!
interface Serial0/0
no ip address
encapsulation frame-relay
clock rate 2000000
end

R2(config)#int s0/0
R2(config-if)#ip add 12.12.12.2 255.255.255.0
R2(config-if)#do sh run | Sec Serial0/0
interface Serial0/0
ip address 12.12.12.2 255.255.255.0
encapsulation frame-relay
clock rate 2000000

If we see, the subinterface is till there even we already delete. So we can not change subinterface to multipoint and the description will be there unless we do router ‘reload’.

R2(config-if)#do sh fram map
Serial0/0 (up): ip 12.12.12.1 dlci 201(0xC9,0x3090), dynamic,
broadcast,
CISCO, status defined, active

R1#sh fram map
Serial0/0.1 (up): point-to-point dlci, dlci 102(0x66,0x1860), broadcast
status defined, active

Check the ping is it still ok or not!

R1#ping 12.12.12.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 12.12.12.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/16/44 ms