How to route network traffic to another network in different sites

[merttuncer]

Hello everyone,

Let's say I have two networks in different locations. These sites connected together via managed MPLS. I need to forward 10.34.4.0 network's traffic to  192.168.204.0 . I've been reading for hours, but cannot find any solution. Both of the routers have static default routes. How can i do that on Cisco router? 

[Jon Marshall]

Not sure I follow what you mean.

If you simply mean you want the two networks to communicate with each other then if each router has a default static route pointing to the provider router and the MPLS network is managed for you then you need to talk to the provider to make sure they are advertising the routes between sites.

If you mean something else please clarify.

Jon

[merttuncer]

Actually both networks talk to each other, i can ping interfaces between them. My question is how can i forward all requests from 10.34.4.0 to 192.168.204.0. 

[Julio E. Moisa]

Hi

The PE routers create a VPN tunnels using MP-BGP through a MPLS network, as the clients are assigned to a VRF these VRFs are redistribuited into the MP BGP address family instance separately from other VRFs, the LDP is used to assign labels to the prefixes and creating a path. 

[Jon Marshall]

It's still not clear what you mean by forward all requests.

Can you give an example ?

Jon

[merttuncer]

When client get ip from 10.3.4.x and opens the internet for the first time they have to be redirected to the portal. This portal's hotspot ip is 192.168.204.2 so i need forward requests from 10.34.4.x. As i sais before these networks cpnnected to each other L3 via MPLS. Thank you all for your patience :)

[Jon Marshall]

Do you want all internet traffic from clients to go via the portal or is it just for signing on ?

PBR will redirect the traffic for you but it would redirect all the time ie. not just for the initial connection.

Jon

[merttuncer]

All the time is okay for me, i'll try and let you know

[Julio E. Moisa]

Hi

Im assuming this is a study case, where you want to create an mpls network, that is correct? Otherwise you need to follow the Jon's advice.

Assuming it is a study case, first you need to understand the network devices used in a MPLS network: C, CE, P, PE

C = Customer router, it represents a router in the internal network.

CE = Customer Edge router, it represents the router connected to the provider, it is located on the edge of the client network, CE and C is not handled by the Provider so no MPLS protocol are running there.

Now we have the routers in the provider network:

PE = Provider Edge router, this kind of router is in charge to create the VPN communication between the PE's, it is possible using Multiprotocol BGP (MP-BGP) and MPLS protocols: LDP or TDP, the most used protocol today is LDP. LDP is used to provide the MPLS service and in charge to exchange label mapping. The provider can have many PE on your networks. The PE routers receive the traffic from the CE routers and this traffic is associated to VRF (same on all the PE or different VRF depending the clients). The VRF creates separate routing tables from the global routing table, in few words I can have the same subnets on my routers and no overlapping will be caused. 

P = Provider router, this type of router is basically the routers inside the Provider network, they are used to tranport the LDP labels. On these routers like PE are configured with LDP protocol. Between P and PE routers you can run OSPF or IS-IS routing protocols to enable the MPLS communication. A P router also can be used to be a PE.

The following is a brief explanation about the study case:

CE Routers have the default route pointing to the PE routers, the provider will not handle these devices unless you have a contract with them saying the oppositive but it is often handled by the client. On the CE you  creates one of the subnet that you mentioned previously (10.34.4.0 or 192.168.204.0) the other CE at the other end will have the other subnet. Or at least an entry into the routing table to know how reach it internally.

The ISP will assign a VRF (with RD and route target) for the client on the PE router, it will be applied under the interface connected to the CE router. Usually this VRF is the same on both PE. Also you create the MP-BGP in order to create the VPN tunnels, this traffic will be handled by the LDP (MPLS protocol), if you are using static routing you can create a static route under the VRF on the PE to know how to reach the client subnet once it is created it will be redistributed into the MP BGP.

For example:

ip route vrf CUSTOMER-A 10.34.4.0 255.255.255.0 10.1.1.1 name CLIENT-SUBNET

router bgp 65000
address-family ipv4 vrf CUSTOMER-A
redistribute static

P Routers are going to pass the traffic only assigning labels to the prefixes to be exchanged creating a path. 

This video can be useful:

https://www.youtube.com/watch?v=3vBA3O22rd8

These are very good links to understand how MPLS works

http://www.cisco.com/c/en/us/support/docs/multiprotocol-label-switching-mpls/mpls/13733-mpls-vpn-basic.html

http://www.cisco.com/c/en/us/td/docs/ios/12_0s/feature/guide/fs_rtr22.html

Please rate the comment if it is useful:

:-)

[Masoud Pourshabanian]

Hello,

As John mentioned, your question is unclear.

If the networks 10.34.4.0 and 192.168.204.0 are directly connected, you issue the following command under BGP and corresponding VRF : redistribute connected.

Address-family ipv4 vrf [name]

redistribute connected.

You issue redistribute static if they are static routes.

If they are dynamic route, it depends on the routing protocol between PE, CE

For IGP, you need redistribution from IGP to BGP under BGP address-family  ipv4 VRF [name]

For BGP, you only need to specify BGP neighbor under address-family ipv4 VRF [name]

Masoud