Incoming Connections problem

[Tanked]

My Area: Greater Manchester
Package: 2Mb

After having a 213* IP address for nearly 4 years I recieved an new one which began with 82*. I have had no problems with this except on incoming connections. I have a FreeBSD UNIX box that I connect to with SSH but since I was given a new address I can no long connect to it. I have changed nothing on my router or firewall software; to make sure the problem was not specific to this box I set up another box with SSH enabled and no firewall but I could not connect to that one either- I keep getting 'connection refused' messages.

A friend of mine who leaves a few streets away also recieved a new IP address and since then he can no longer connect to his computer with PC Anywhere.

Any help with this is greatly appreciated.

[Druchii]

Sounds like yet another blocked port range to me.

[Tanked]

I thought it may be, but a few google searches didn't show anything about NTL blocking ports.

[Chris W]

There are only a very small number of ports that are blocked on ntl- i can't remember the list, but certainly nothing that will affect SSH.

---------- Post added at 22:43 ---------- Previous post was at 22:40 ----------

hmm.... ssh: connect to host 82.***.***.*** port 22: Operation timed out

can't connect from here either.

---------- Post added at 22:46 ---------- Previous post was at 22:43 ----------

you definately getting connection refused, not time out?

[Tanked]

If I connect from home (using the NTL external addrress) I get the connection refused error. If I connect from work with the Windows Putty client I get the 'Software caused connection abort' which probably means it timed out

[dunkyb]

Hi Tanked,

This is probably obvious to you so sorry for mentioning, but just in case.. Are you sure sshd is not trying to bind to your old IP address? Check sshd_config for ListenAddress?

netstat -lpn (in linux at least) will give an idea of what's listening on which port...

Can you see the incoming SSH packets hit your machine?

[Tanked]

Hello, thanks for replying.

My broadband router forwards all port 22 connections to the internal private address of my FreeBSD box. On my FreeBSD box I have the pf firewall installed. I have checked the firewall logs as well as the system log at /var/log/auth.log and niether of them have any records of attempted ssh connections so they are not even getting to the box. I disabled the pf firewall and got the same result; I also set up an entirely new box with justt ssh running and still no joy.

The only possibilities are that its an NTL network issue or my router has just developed a problem at exactly the same time I recieved a new IP address. Interestingly, My router's system time is exactly one hour behind the actual time, and the time stamps of the entries in the router's system logs are completely out of sync, see example below:

2006/05/05 19:45:41 : Syncronize system time to Fri May 5 19:45:41 2006
2006/05/04 19:45:41 : Syncronize system time to Thu May 4 19:45:41 2006
1970/01/01 00:00:03 : dhcpc: Entering BOUND state.
1970/01/01 00:00:03 : Get Dns[WAN][1]=194.168.8.100
1970/01/01 00:00:03 : Get Dns[WAN][0]=194.168.4.100
1970/01/01 00:00:03 : Get Gateway[WAN][0] = 82.*.*.*
1970/01/01 00:00:03 : Get Netmask[WAN]=255.255.252.0
1970/01/01 00:00:03 : Get Ip [WAN]=82.*.*.*
1970/01/01 00:00:03 : Dhcp client renew
1970/01/01 00:00:03 : Got DHCPACK (IP = 82.*.*.*, duration = 541045 secs)
1970/01/01 00:00:02 : dhcpc: Entering requesting state.
1970/01/01 00:00:02 : dhcp: Entered SELECTING state.
1970/01/01 00:00:01 : dhcp: DHCPOFFER message accepted.
1970/01/01 00:00:00 : dhcp: Process DHCP message in WAIT_OFFER state.
1970/01/01 00:00:00 : dhcpc: Entered WAIT_OFFER state.
1970/01/01 00:00:00 : Sending DHCPDISCOVER
1970/01/01 00:00:00 : dhcpc: Entered INIT state.
1970/01/01 00:00:00 : Dhcpc_UsrStart()DHCP Client Started.


I have a Mentor router which has been running fine for the past few years; if the time being out of sync is an issue then I'm unsure of what to do as it is set to GMT and also automatically uses SNTP

Thanks for any help

*edit* I've now set the correct time on my router, the log entries are now appearing with normal time stamps but I still can't ssh into my machine using the external NTL address.

[Jon T]

I know this may be no help at all, but at the moment we are an hour infront of GMT, so your routers timestamps being an hour behind would appear normal.

[Tanked]

I can remotely manage my router by typing in http://<external ip address>:8080 in a browser (disabled now). I then tried to get ssh to listen on port 8080, once I did this I still could not connect but I got a different error message: 'the server unexpectedly closed the connection'. This happened when attempting to connect to both my UNIX boxes. I don't think there is anything wrong with my router, I think NTL is blocking incoming ssh connections.

[dunkyb]

I can remotely manage my router by typing in http://<external ip address>:8080 in a browser (disabled now). I then tried to get ssh to listen on port 8080, once I did this I still could not connect but I got a different error message: 'the server unexpectedly closed the connection'. This happened when attempting to connect to both my UNIX boxes. I don't think there is anything wrong with my router, I think NTL is blocking incoming ssh connections.

NTL is not blocking SSH connections, I can connect to my box remotely via SSH ..... (on port 22 aswell)

How about connecting your UNIX box directly to the CM temporarily and see if you can connect from a remote machine, to see if this eliminates the problem ? If so then the router is at fault.

Try factory resetting the router? I had a Mentor router once which lasted 2hrs (No joke) Don't see why it'd develop this problem though, but still!

Hope this helps.

[Tanked]

You were correct dunkyb. When I attached the cable to my UNIX box I re-registered and recieved an new IP address- I could then ssh into my box. In case the problem was with the IP addresses themselves, I gave my router a new MAC address, re-registered it and it then recieved a brand new address; however, ssh did not work again, so its bye-bye to the router.

Its a tad annoying that my router craps out at the exact time NTL issues new IP addresses, if they hadn't done that I would have suspected a router problem a lot sooner- I'd be very interested to know why my router still accepts incoming http connections on port 8080- perhaps the Virtual server/port-forwarding function that I use for incoming ssh connections simply doesn't work anymore.

Thanks to everyone who replied, and incidentally does anyone have a recommendation for a good hardware firewall/router?

[jtwn]

You could try setting your computer as a DMZ on your router and seeing how it works if you still wish to try with it.

[Tanked]

Thanks but I've tried that, as well as setting the router back to it's factory settings but nothing has worked. Any ideas for a good firewall/router?

[darkone338]

linksys or smc barricade have always worked well for me.