Question on Merging Two Networks

[nunzeo]

I am looking to merge two networks (on the same LAN) and have a question.

Network A router is 192.168.100.1

Network B router is 167.233.100.1

If I want to be able to route clients from the 192 network to the 167 network, can I do the following:

Create static route on 192.168.1001 for

167.233.100.0 /24 for next hop to 167.233.100.1

Or do I have to do the following:

Put in and additional router:
192.168.100.2 for interface1
167.233.100.2 for interface2

Then create static route on 192.168.100.1 for

167.233.100.0 /24 for next hop to 192.168.100.2

Thanks.

 

[North323]

you can create static routes. you may also have to incorporate a routing protocol

 

[nunzeo]

this is just temporary so no routing protocol needed at this time. but can i do a route on the 192 router as such 167.233.100.0 /24 for next hop to 167.233.100.1? or does the route on the 192 router have to route to another 192 router that is directly connected to the 167 network configured on the other interface. hope i am explaining correctly.

 

[North323]

as long as the two routers are connected somehow. it will route to directly connected networks

 

[nunzeo]

they are two seperate physical routers. so router A 192.168.10.1 / 24 would be plugged into the same layer 2 switch as router B 167.233.100.1 /24. so i am guessing they are not directly connected? so then i need another router with one interface on the 192 side and the other on the 167 side?

 

[North323]

can the router create vlans?

 

[nunzeo]

no but i do understand what you are saying. at that point i could create a vlans on that router and then they are directly connected. i guess my whole point of this thread was to get the answer on if those networks had to be directly connected.

thanks for your help.

 

[North323]

yes they have to be directly connected. you can do it by creating vlans on the router and connect them to the switch

 

[nunzeo]

thanks. got it. i guess i knew the answer but just wanted reassurance.

 

[VinceWhirlwind]

If all your users are on the same switch, then it might simplify things a bit if you eliminate one router.
On the remaining router you can add the eliminated router's LAN interface as an "ip address secondary". that way, clients can plug into any switchport on your network and both "merged" networks are routed the same with no need for any routes to be added.

If you want to keep two routers, then I can see two basic options.

1/ make a direct connection between the two routers and configure the two new connected interfaces as a 3rd subnet. Then each router will need a route to the other, pointing at the new router interface.

2/ use the existing switch connection from each router by adding an "IP address secondary" to each router's LAN interface.

Finally, you could separate your two subnets on the switch using VLANs. Your switch uplink port will need to be configured as a dot1q trunk:

int f1/0/48
swi tr encap dot1q
swi mo trunk

Your router LAN interface will be a dot1q trunk as well:

int f0/0
no ip addr
int f0/0.10
encap dot1q 10
ip address 192.168.100.1 255.255.255.0
int f0/0.20
encap dot1q 20
ip addr 167.233.100.1 255.255.255.0

 

[nunzeo]

thanks for the info vincewhirlwind. i will try some of your suggestions out.

nunzeo

 

[nunzeo]

VinceWhirlwind,

I have a question. If I use the option to add an "IP address secondary" to the existing LAN interface as such

1st 167.233.100.1 /24
2nd 192.168.1.1/24

and then I connect that interface into a layer 2 switch, should I be able to ping both gateways as long as I configured the clients on that same subnet? What if I have multiple switches connected via uplink ports. Should I be about to ping both gateways if I am two switches over from the switch directly plugged into the router.

I guess I will test first but I was curious.

Thanks,
Nunzeo

 

[VinceWhirlwind]

Unless you do something funny with your switch configs, then any host in one subnet on that switch should be able to ping that subnet's GW address, ie, router interface.

It's a long time since I played with secondary IP addresses, so I can't remember if there are any gotchas.