pat for connections from the internal network

Jan 18, 2008 5 Replies

hello everyone,



I googled around a bit trying to understand the problem, but I didn't find anything useful



I've an 877 model and the problem is:



there is a public ip configured on an interface and a private one on another one there is a dynamic nat rule which permits to the clients on the private lan to go on the internet natted with the public ip there is also a pat rule which maps the port 80 of an internal ip to the external one, it permits to the clients on the internet to access the webserver on the private lan



everything works well, at exception of one thing:



when a client from the internal network, tries to contact the public ip address at the port 80, it's not been patted to the other internal ip (as happens for who connects from internet), it receives instead a connection refused



do you have any suggestion on something I could look at?



thanks in advance, Giulio Fidente


Giulio,

Clients on your internal network shouldn't be trying to access an internal server through it's public IP. NAT won't work this way. Internal clients need to use the internal IP address of the server and leave the public IP address for the external clients. Hope that helps.

neteng

formatting link

thanks first of all for your reply,

they should not, you're right ... but the dns resolves the website with its public ip address, so the internal clients are directed to the public ip, is something wrong here? is there anything I should do to avoid this "path" ?

2 possible solutions. You can hand a second router off the first and access it via its public IP that way, or run split horizon DNS and return the private IP for internal clients

you can *hang* a second router.. not hand

thanks for your help guys,

to be honest I was hoping that a certain setting was able to do the game on the cisco router ... but I didn't find any so I'll go for the split horizon solution I think

Giulio Fidente

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