The best way to connect 2 lan's with the same IP addresses.

[m_tikshuv1]

Hi,

I'v two networks with the same addresses. i'v been ask to find a the best way to connect them together without the use of a NAT.

And both of them will talk to an out side source...

Can some one help me?????

Regards,

Michel Vaillancourt 

[jonallport]

You have a couple of (potential) issues here:

• They will have to be bridged (l2 forwarding) rather than routed - very heavy on your WAN links, especially if you have traffic that uses broadcast a lot (like Windows networking)

• There are likely to be address conflicts (same IP address used in both locations)

I'm assuming these sites are far apart, so a dark fiber run or some other bridge is out of the question.

My recommendation would be to bite the bullet and put a new IP scheme in at one of the sites.  I would never look to bridge over WAN.

If you insist on carrying on then it's L2TP you need to use.  I have no experience with that I'm afraid.

[m_tikshuv1]

Hi,

Thank's for your help.what is your opinion on configure Nat instead?

Michel vaillancourt 

[saif musa]

Michel,

You cannot use NAT between two networks with the same IP address range. NAT is process utilized by routers, routers only implemented between different networks. even if you forced router to connect similar networks it will not accept same ip address range on its different interfaces.

as jonallport said, you don’t have just bridging theory knowing that you will have conflicts as long as you are using the same ip address.

Hope that helps

[foo.bk001]

Have you considered using bridge group or EVN?

I think best way to go is to change the IP addresses, but it's not always possible in a production environment.