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connecting 2 different networks with 2 different router

kamal el assaad
Level 1
Level 1

hello 

 

how can i connect 2 different network which has 2 different routers.

what are the best solution and the protocols used to solve this problem

 

note: the 2 networks has the same vlan name and number.

 

thank you in advance

12 Replies 12

balaji.bandi
Hall of Fame
Hall of Fame

We are not clear about the VLAN and IP address.

 

Can you please explain more details about 2 different networks.and 2 Different Routers (what router model and IOS, and running config to look what is already there)

 

High level you can do below :

1. if they are 2 Different networks , VLAN Stay Locally ( as Long as the IP address not over lapping)

2. You can create a Point to Point Link and redistribute the network using static route or dynamic routing with IGP protocol.

3. we are not sure how far these 2 Routers, same Location or different Geo Locations ?

4. how is the connectivity over internet or dedicated link if they using WAN ?

BB

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first thanks for your quick response,

the network was configured all as same vlans. suddenly this network is divided into 2 networks: network 1 and network 2.

network 1 cross network 2 in the middle. so now network 2 is disconnected as a distance and i need to connect the separated parts of network 2 without having routing loop.

the connection used is fiber wan and LAN.

the switches used are IE5000

 

Am I correct in understanding that you have 2 IE5000 switches and a fiber wan connecting them, and that the switches will have some vlans where the same vlan number is used on both switches? That should not be a problem. If the switches have the same vlan number, do they also use the same IP addressing/same subnets on both switches? Same subnets on both switches will create a problem and would need address translation to resolve it, but I am not sure that IE5000 supports address translation. 

 

As far as connecting the switches is concerned just make the fiber wan into a transit subnet. Assign addresses to the interfaces of each switch in some new subnet that is not used in your network anywhere. Make sure that ip routing is enabled on both switches. You could run a dynamic routing protocol between the switches using the transit vlan to communicate. But it would also be possible to configure static routes on each switch for the subnets of the other switch and not need a dynamic routing protocol.

HTH

Rick

I have 3 IE5000 switches, in the beginning, all was one single network, but after they were composed into 2 different networks, one switch in network 1 and 2 switches in network 2, but the idea is network 2 is not connected physically directly cause of network 1 is like an island between them.

 

so I need to let network 2 which contain 2 switches from the opposite side and separated by the network 1, to connect each other and to see each other without having a routing loop in the hall network.

I still do not have a good understanding of the topology of the networks you describe. Perhaps you could post a simple diagram which illustrates the networks.

HTH

Rick

kindly find the diagram.
i should connect the north side of network 1 using the IE5000 located in
network 2 to reach the south side of network 1.
or if i can make logical bridge between the north and south directly using
some protocols if is it possible.

the main idea is when i connect both side is to avoid routing looping in
the project which include both network 1 and 2.

You mention a diagram but I do not see any diagram. Based on the additional information in your recent post I do have another question. Are the devices in the north side of network 1 use the same IP subnet as the devices in the south side of network 1? What I am getting at is whether a source in the north side of network 1 needs to be able to arp for the destination in the south side of network 1. If they do need to arp this will limit the type of solution that can be used. If they do not need to arp then there is a variety of possible solutions.

HTH

Rick

the devices in the north has different IP address than the south, and we should use ARP.

Perhaps my question was not clear. And perhaps if we had the diagram I could understand it better. But let me explain in a different way what I was trying to ask. If the north side was using one subnet (perhaps 10.10.10.0/24) and if the south side was using a different subnet (perhaps 10.30.30.0/24), and if the network in the middle was a different subnet (perhaps 10.20.20.0/24) then each of the networks would have a gateway (probably the address of the switch) which would forward traffic between the networks. So if there was a user in the north side who wanted to send something to the south side that user would arp for the gateway device but would not arp for 10.30.30.x.

 

Or if the north side was using a subnet (perhaps 10.10.10.0/24) and if the south side was also using addresses in that same subnet then a user on the north side would need to send an arp all the way to the south side to find the destination address. 

 

So I am asking whether the north side and the south side are in separate, distinct networks with gateway devices between networks, or both are using IP addresses in the same address range.

HTH

Rick

first thanks for your interesting ,

the north and south side has example ( 10.10.10.0/24) and the middle has (
10.30.30.0/24).

the block diagram is just a drawing by hand showing in the middle network 1
with an assumption subnet and north and south as network 2 with same
subnet.

If I am understanding correctly there is an IE5000 switch for the north and it has a vlan (perhaps vlan 10) using subnet 10.10.10.0/24. Probably this switch has a vlan interface for the vlan to provide routing for the subnet. This switch connects to another IE5000 switch that has another vlan (perhaps vlan 30) using subnet 10.30.30.0/24. Probably this switch has a vlan interface for the vlan to provide routing for the subnet. That switch connects to an IE5000 switch for the south which has the same vlan and the same subnet as the north. This switch might or might not have a vlan interface for the vlan to provide routing. If this is correct then there is a simple solution for you. Make a connection between the north switch and the middle switch on access ports assigned to vlan 10. And make a connection between the south switch and the middle switch on access ports assigned to vlan 10. As long as the middle switch does not have a vlan interface for vlan 10 then the networks will be separated, the north and the south will be able to communicate, and there will not be any routing loop.

HTH

Rick

this solution is perfect in case they are in one broadcast domain, but in
our case we have 2 different broadcast domain.
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