NAT Query

[GRANT3779]

Hi,

I'm wondering -

If I have the following - Site A and Site B separated by WAN connection say MPLS.

Site B has no Internet connection / or associated External IP addresses.

Site A does have Internet Breakout / External addresses.

Is it possible for me to setup an inbound NAT at site A for a LAN address at Site B to be accessible externally?

Or do NATs have to be used locally to the site the external address terminate at?

[Jon Marshall]

There is no requirement for NAT to be local to the site.

As long as the real IP is routable from site A then it should work fine.

Jon

[GRANT3779]

Thanks Jon,

And it's all setup in exact the same way as If it was a NAT for a local address? Nothing special needed? Apart from the routing in place?

[Jon Marshall]

Nothing special needed.

Jon

[GRANT3779]

Hi Jon,

Apologies digging up this one again -

If someone externally communicates to the inside Server address at Site B through the NAT from site A's external addressing. How is the return traffic from Site B address handled? Would Site B need to have a default route pointing to Site A to be able to get out to the Internet from Inside to Out?

E.G - External Static Nat at Site A for a host in Site B (Sites separated via MPLS WAN). 

Someone from Outside contacts the external address - it hits Site A NAT which routes to inside address at Side B. 
For Site B to then communicate back - does this need to know where the public address space sits and have a route to it through Site A.

[paul driver]

Hello

You can nat from an public routable outside ip address to a none routable inside address

Stie A

ip nat outside static (site B public ip) (site A private ip)

res

Paul