Two Subnets, 1 CiscoRouter, Can they Communicate?

[pdecker]

Hi, I have two subnets, each on a seperate Fast Ethernet interface of a single Cisco Router (2621xm), I want them both to be able to communicate with each other. Here is a bad ascii picture of the setup

----------------------------------------
| Cisco 2621xm Router |
| [F.Eth 0/1] [F.Eth 0/0] |
| 192.168.1.1 214.4.4.1 |
--------|--------------------|----------
| |
[switch1] [switch2]
/ 192.168.1.x 214.4.4.x

As of right now I have both Fast ethernet (F.Eth) interfaces on the Cisco 2621xm router configured with the IP addresses shown.

As of right now the computers on the 192.168.1.x can ping the F.Eth0/1 interface, but not the F.Eth0/0 interface, and vice versa for the computers on 214.4.4.x

What needs to be configured to allow the two subnets to be able to communicate through the router?

Is there a way other than through IP Routing? Do I really need to use a protocol such as RIP?

Im still trying to learn the routing basics.... thanks for any help!

 

[eurobadger]

Hi

Well, you will need IP routing. RIP is the easiest, and version 1 or 2 will do for this task.

Otherwise you could configure static routes in both directions.

http://www.cisco.com

has some examples.

EB

"The most powerful command you will ever use is rtfm"
EB

 

[pdecker]

thanks for the reply,

It seems that I have never set up rip successfully. What would be a sample config for the above setup? the Cisco examples for RIP don't seem to work, but then again I could interpret the commands wrong. Can someone give me a sample? this is what I would do:

config t
router rip
network 192.168.1.0
network 214.4.4.0

thats what I gathered was needed for RIP from cisco's information. But it still doesn't let a computer on the 192.168.1.x communicate (ping) with a computer on the 214.4.4.1 , any suggestions?

Also, IP Routing doesnt seem to work because the router won't accept itself as the next hop. I did:

ip route 192.168.1.0 255.255.255.0 192.168.1.1
ip route 214.4.4.0 255.255.255.0 214.4.4.1

both times it says i cant use this router as the next hop. any suggestions on using rip?

 

[rburke]

Are there any access-list configured in the router? The router will know how to route to directly conected subnets like you are taling about, so no routing statements should be needed to route between them. The only reason they wouldn't be working is if there is some ind of access-list stopping it. You might want to post your config (changing passwordsd and IPs) so that we can take a look.

Burke

 

[jimmyzz]

pdecker,

Are your PCs configured with a default gateway? PCs on the 214.4.4.x should be configure with a default gw of 214.4.4.1 and PCs on the 192.168.1.x should have a default gw of 192.168.1.1.

Your ip route statements would be obsolete because the routers know these networks are directly connected.

JimmyZ

 

[wybnormal]

The router does not need RIP or any other routing protocol for these two DIRECTLY ATTACHED (connected) networks. JimmyZ and Rburke have the right idea by looking somewhere else such as default gateway issues etc.

Remove any access list and any RIP for now.

MikeS


Find me at

http://www.packetattack.com

"Take advantage of the enemy's unreadiness, make your way by unexpected routes, and attack unguarded spots."
Sun Tzu

 

[Jsteve]

wybnormal is correct, you only have one router. so you don't need RIP and static routes, only use those configs f you have two or more routers connected. That's why your getting the static route error message because you do not have a next hop.

Is your interface administratively up?
config t
int fa0/1
ip address 192.168.1.1 255.255.255.0
no shutdown

 

[pdecker]

To all : Thanks for the advice, I will make sure the gateways are set for both networks. Also, do I need to enable ip routing? ie. "ip routing" at the config prompt? I'll let you know what happens.

 

[wybnormal]

normally routing is enable by default.. unless someone disabled it to make a very expensive bridge

When you do a :

show ip route

you should see two subnets with a C which means they are "connected directly"

!
C 192.168.50.0/24 is directly connected, Ethernet0
C 192.168.1.0/24 is directly connected, Ethernet1
!

The default gateway for each subnet is the ethernet interface for that subnet..

MikeS



Find me at

http://www.packetattack.com

"Take advantage of the enemy's unreadiness, make your way by unexpected routes, and attack unguarded spots."
Sun Tzu