cancel
Showing results for 
Search instead for 
Did you mean: 

D-Link DSL-504 Port Redirect

N/A

D-Link DSL-504 Port Redirect

Hi all DSL-504 users, and any others who may be able to help!
I'm using this router & I'm running an FTP server on one of the PCs connected to it. I can connect to the FTP server from another PC on the LAN, so I know the server is OK. I set up a port redirection on the router to redirect port 21 traffic to port 21 on the server machine. I tried ftp-ing my internet IP address and I get "ftp: connect :10071
" - TCP sesion closed by server. The connection doesn't seem to be getting to the server, so is there something I've missed on the router config? Has anyone else got an FTP / HTTP server running on their PlusNet account via this router?
TIA
David
7 REPLIES
N/A

RE: D-Link DSL-504 Port Redirect

Are you running dhcp or statics on network and what ftp server software are you running
N/A

RE: D-Link DSL-504 Port Redirect

DHCP, but the IP address of the server hasn't changed since I set up the redirect. Does this matter? Do redirects only work to statically assigned IPs? I'm using WAR FTP server software, it's setup OK because I can access it from other PCs on the LAN & it's not even recieving the requests that come in from the Internet. It must be either the router or PlusNet that is blocking the traffic.
Is anybody else running an FTP server on their PlusNet account?


> Are you running dhcp or statics on network and what ftp server software are you running
>

N/A

RE: D-Link DSL-504 Port Redirect


Hi,

FTP is a bit wierd port-wise.

When a client connects to a server, the client connects FROM a high port to port 21 on the server. Once a connection is established and data requested, the SERVER connects FROM port 20 TO a high port on the client.

Possible problems here are that the router is blocking this outbound connection. Another is that as the SERVER has a local, private IP number, this is not being converted to the external IP address of your ADSL connection when it passes through the router. As this address is also included is the data contained in the packets as well as the source address. For this, you'll need an 'application gateway' on the router - a built in program that 'opens up' the ftp packets and changes the IP address. Most routers will have this built in.

Another alternative is to use PASV mode when connecting with ftp. When you us this, rather than have the server try to connect back to the client on port 20, the machines negotiate a high port to high port connection that is established FROM the client.

For more details, check out:

http://www.google.com/search?q=ftp+port+pasv



N/A

RE: D-Link DSL-504 Port Redirect

Ah,
Didn't think of that, I've had problems FTPing before due to the client firewall blocking inbound connections. I was hoping that this would be handled automatically by the router, specially since when selecting FTP in the redirect setup it lists ports 20 & 21. I'll try a passive connect and see what happens.......
Cheers,
David

>
> Hi,
>
> FTP is a bit wierd port-wise.
>
> When a client connects to a server, the client connects FROM a high port to port 21 on the server. Once a connection is established and data requested, the SERVER connects FROM port 20 TO a high port on the client.
>
> Possible problems here are that the router is blocking this outbound connection. Another is that as the SERVER has a local, private IP number, this is not being converted to the external IP address of your ADSL connection when it passes through the router. As this address is also included is the data contained in the packets as well as the source address. For this, you'll need an 'application gateway' on the router - a built in program that 'opens up' the ftp packets and changes the IP address. Most routers will have this built in.
>
> Another alternative is to use PASV mode when connecting with ftp. When you us this, rather than have the server try to connect back to the client on port 20, the machines negotiate a high port to high port connection that is established FROM the client.
>
> For more details, check out:
>
> http://www.google.com/search?q=ftp+port+pasv
>
>
>
>

N/A

RE: D-Link DSL-504 Port Redirect

Hi,

I don't know anything about that router but I guess that if it's aimed at domestic use, any built in ftp application gateways will be set up for internal ftp clients connecting to external ftp servers and not the other way around.

There are some good tech forums on adslguide.org.uk that cover stuff like this - good chance someonw with the same hardware will know what to do.
N/A

RE: D-Link DSL-504 Port Redirect

Thanks for the pointer, had a look on adslguide & did a google search too. Looks like I'm not the only one having port redirect problems with the DSL-504..... Tried a few suggestions, but still not working yet. I'll get on to D-Link support on Monday. I'll post a solution when I have it.....
Anybody planning on running their own servers might want to consider a different router Sad


> Hi,
>
> I don't know anything about that router but I guess that if it's aimed at domestic use, any built in ftp application gateways will be set up for internal ftp clients connecting to external ftp servers and not the other way around.
>
> There are some good tech forums on adslguide.org.uk that cover stuff like this - good chance someonw with the same hardware will know what to do.
>

N/A

FIXED - RE: D-Link DSL-504 Port Redirect - FIXED

DOH!
The router only applies the redirect to traffic originating WAN-side. So, even though I was using my external IP address, the router wouldn't redirect traffic coming from a machine on the LAN-side. I VPNed out to another network, tried again & hey-presto! it works. Traffic going up the VPN tunnel bypasses the router and has to come back in from the WAN-side and is therefore redirected correctly. Simple huh? Now I know why I never got involved in the networking side of the industry Smiley




> Hi all DSL-504 users, and any others who may be able to help!
> I'm using this router & I'm running an FTP server on one of the PCs connected to it. I can connect to the FTP server from another PC on the LAN, so I know the server is OK. I set up a port redirection on the router to redirect port 21 traffic to port 21 on the server machine. I tried ftp-ing my internet IP address and I get "ftp: connect :10071
> " - TCP sesion closed by server. The connection doesn't seem to be getting to the server, so is there something I've missed on the router config? Has anyone else got an FTP / HTTP server running on their PlusNet account via this router?
> TIA
> David