Routing between two lan subnets without Layer3 Switch

[fmatrine]

Dear Sir,

We have a hub and spoke WAN network with on central location and 7 remote location

At central location we have LAN subnet as 192.168.1.X/24 and 10.10.1.X/24

At all remote location we have LAN subnet as 10.10.2.X, 10.10.3.X/24 etc..

We have AS/400 and exchange server at central location.

IP for exchange server is 192.168.1.2

IP for router ethernet is 10.10.1.1

IP for As/400 server is 10.10.1.2

All the lan hosts at central location are using subnet 192.168.1.X

All the remote location connect to central location and access the As/400 server.

New requirement is to allow all the remoe location access to central end exchange server.

How to proceed.

Can giving secondary IP on the router ethernet (192.168.1.1/24) solve the above purpose.

We don't want to buy a layer 3 switch at central end also we don't want to invest in buying extra ethernet port card for the second lan subnet at central site.

Also will implementing inter vlan routing on central end router solve the purpose (Do we need to create vlan on the l2 switches and trunk the vlan to router ethernet port)

Pls advice with sample config for above scenario.

Regards

Deepak.

[tbaranski]

It's hard to know exactly how things are laid out without a drawing, but if the remote hosts are currently able to access the AS/400, they should be able to access the Exchange server in a similar fashion. If the central router is able to reach the Exchange server and the Exchange servers knows to send traffic destined to 10.10.x.x to the central router, all should be well.

[fmatrine]

Dear Sir,

Exchange server is in other subnet 192.168.1.X

Router ethernet is configured for 10.x.x.x subnet only.

Can configuring secondary IP address on the router ethernet port solve the routing purpose for 10.x.x.x as well as 192.168.1.x subnet.

Regards

[Craig Norborg]

This is commonly known to Cisco as a "router on a stick" method. Using a single cable between your Cisco router and a switch to trunk and do routing between the VLAN's on the router.

Lets say that your Exchange is one VLAN 50 while your normal LAN is on VLAN 1.

Router Config

interface FastEthernet0/0

no ip address

speed 100

full-duplex

!

interface FastEthernet0/0.1

encapsulation dot1Q 1 native

ip address 10.0.0.1 255.0.0.0

!

interface FastEthernet0/0.50

encapsulation dot1Q 50

ip address 192.168.1.1 255.255.255.0

Switch config will depend on type of switch. If its a 2950/3550 (something with 12.1 IOS), they only support dot1Q trunking, so all you need to do is a "switchport mode trunk" on the interface and put "vlan 1,50" in the VLAN database of the switch.

If you're running an older 12.0 IOS switch (35/2900XL switches), you would need to make sure you do a "switchport trunk encapsulation dot1q" in addition to the "switchport mode trunk" command.

CatOS is similar also. All in all - fairly simple!!

[fmatrine]

Dear Sir,

Thanks for the suggestion