evilrouters.net

Last night I put together a basic frame relay lab for dynamips, made up of three routers: one hub and two spokes. I’m sure there are a thousand others out there like it but I was putting something together to get a friend started on dynamips and it’s what I came up with.

First, the physical topology:

R1 is our hub router and R2 and R3 are our spoke routers. Each router has loopback0 configured with an IP address of 172.16.x.x and each’s serial0/0 interface is configured with an IP address of 172.16.123.x, “x” being the router number (1/2/3), of course. We also throw EIGRP into the mix to get full connectivity between devices (we’ll need full connectivity for my next lab).

Dynagen .net file:

autostart = false

[localhost:7200]

     workingdir = /home/jlgaddis/dynamips/working/frame-relay

     [[3640]]
          image = /home/jlgaddis/dynamips/ios/c3640-jk9o3s-mz.123-14.T7.img
          idlepc = 0x60530abc
          ram = 128
          disk0 = 8
          disk1 = 0
          mmap = true
          ghostios = true

     [[ROUTER R1]]
          model = 3640
          console = 2000
          slot0 = NM-4T
          s0/0 = FR 1

     [[ROUTER R2]]
          model = 3640
          console = 2001
          slot0 = NM-4T
          s0/0 = FR 2

     [[ROUTER R3]]
          model = 3640
          console = 2002
          slot0 = NM-4T
          s0/0 = FR 3

     [[FRSW FR]]
          1:102 = 2:201
          1:103 = 3:301

R1 Configuration:

hostname R1
!
interface loopback 0
 ip address 172.16.1.1 255.255.255.255
!
interface serial 0/0
 encapsulation frame-relay
 no frame-relay inverse-arp
 ip address 172.16.123.1 255.255.255.0
 frame-relay map ip 172.16.123.2 102 broadcast
 frame-relay map ip 172.16.123.3 103 broadcast
 no ip split-horizon eigrp 123
 no shutdown
!
router eigrp 123
 network 172.16.1.1 0.0.0.0
 network 172.16.123.0 0.0.0.255
!

R2 Configuration:

hostname R2
!
interface loopback 0
 ip address 172.16.2.2 255.255.255.255
!
interface serial 0/0
 encapsulation frame-relay
 no frame-relay inverse-arp
 ip address 172.16.123.2 255.255.255.0
 frame-relay map ip 172.16.123.1 201 broadcast
 frame-relay map ip 172.16.123.3 201
 no shutdown
!
router eigrp 123
 network 172.16.2.2 0.0.0.0
 network 172.16.123.0 0.0.0.255
!

R3 Configuration:

hostname R3
!
interface loopback 0
 ip address 172.16.3.3 255.255.255.255
!
interface serial 0/0
 encapsulation frame-relay
 no frame-relay inverse-arp
 ip address 172.16.123.3 255.255.255.0
 frame-relay map ip 172.16.123.1 301 broadcast
 frame-relay map ip 172.16.123.2 301
 no shutdown
!
router eigrp 123
 network 172.16.3.3 0.0.0.0
 network 172.16.123.0 0.0.0.255
!

Now that everything is up and running, let’s verify that we have full connectivity between our three routers:

R1#ping 172.16.123.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.123.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/23/36 ms
R1#ping 172.16.123.3

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.123.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 12/17/20 ms
R1#show ip route eigrp
     172.16.0.0/16 is variably subnetted, 4 subnets, 2 masks
D       172.16.3.3/32 [90/2297856] via 172.16.123.3, 00:01:17, Serial0/0
D       172.16.2.2/32 [90/2297856] via 172.16.123.2, 00:01:17, Serial0/0

R2#ping 172.16.123.3

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.123.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/30/48 ms
R2#ping 172.16.3.3

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.3.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/29/44 ms

R3#ping 172.16.2.2 source 172.16.3.3

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.2.2, timeout is 2 seconds:
Packet sent with a source address of 172.16.3.3
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 24/31/40 ms

Success! We have full connectivity across our frame relay network. My next lab will be covering how to set up an IPSec site-to-site VPN between R2 and R3 to encrypt our data in transit.