IP Networking

I have been asking this question on several Mac community sites but never got a answer. I hope some of you UNIX gurus can provide me with the right kind of information

Why is my system calling my router and how can I prevent it?

I have a Power Mac QS 733 with MacOS 10.1.5 (as you already know under the Mac GUI Unix rules) and connect to internet via ISDN using DHCP with a Zyxel 100IH Router. My computer is the only one who is connected to the Routers hub. The idle timeout is set to 15 sec.

When I'm closing my connection (quitting all mail/web programs) the router times out and in a couple of seconds it's connect again 15 sec., times out and connect again 15 sec ....................... The only way to kill this behavior is to switch of the power to the router.

It's very annoying since I pay for the time I am online. Strange is, this is not happening all the time, but sometimes it's very frequently.

I used a sniffer program to view what's happening, when the Router connects the sniffer register the following source 192.168.1.33.49204 the three last digits is different for each connection. 192.168.1.33 I believe is IP address of my computer but what is the last five digits?

If I reboot my computer it connects at the login but after that the router time out and will just idle. The problem only appears If I then connect to the net and then disconnect.

This behavior dosen't exist when I'm using a PC with Win 98/Win2k (shame on me) or mac OS 9.

As a newbie to Unix and not used to the terminal please advice me

Any help in this matter is highly appreciated.

The 49204 is your local port. If you had a mainstream unix system you obtain a public domain program called lsof. Then the command "lsof -i :49204" would tell you who had that port open. But I don't know if you can get lsof for your mac. You need to get the ip address/port for the other side of the connection. Once we know that port number we can probably tell you with certainty what's going on. We also need to know which protocol is involved and you sniffer can probably tell you that. Since you descibe this as a "connection", I'm guessing that it's tcp.

Do you have a program called gated or routed running? If so that means you have configured your mac to be a router, something that is needed only if it is connected to several networks. If you do that, it must communicate with other routers, but not via tcp.

Thanks for your reply!



lsof is in my system as you can see. When I'm doing the "lsof -i : 49208" nothing is happening as you see in the image.




Here is the sniffer program, I have closed my webbrowser and the Router has timed out (17:33:59).
The Router then connects to Versiontracker (time.17:34:09) "versiontracker.com" was the last site I visited.
This is what makes me cray, must be something in the system that keeps the request from versiontracker to connect




This is how the "Network preferens panel" looks.

I have non of the programs you mention installed.

Your router's IP address is 192.168.1.1. And that sniffer window only shows it sending out a few broadcasts.

You say "The Router then connects to Versiontracker (time.17:34:09)", but that's not what the sniffer shows. Your ip address is 192.168.1.33 and so it had to be your box that established the connection.

Reproduce this situation and try
netstat -an | grep 49208

I'm betting that the socket in question will be in TIME_WAIT mode. If so, this is harmless and it will not cause packets to be exchanged with your router. TIME_WAIT just means that port 49208 has very recently been used in a connection, so it cannot be used again for awhile. That way if stray packets from the old connection come though late, they cannot screw up a new connection.

I can't tell why your box is opening a http connection to a recently visited site. Maybe you haven't shut down your browser after all. Maybe your brower forked to handle a pop-up ad or something.

Perhaps if asked those mac sites "why does my system seem to be opening http connections to some recently visited sites?", you might get a little further. Your original question, "Why is my system calling my router and how can I prevent it?" was more than a little off the mark.

If you do figure this out, please post back and let know what the final fix was.

Since English is my second laungue and I'm a newbie to Unix maybe I did explain things a little unclear.

I will let you know if I solve the problem.

Thanks!

Problem solved in the "network pref. pan." there is 4 options to choose from.
"manually"
"Using DHCP with manual IP address"
"Using DHCP"
"Using BootP"

The default choice was "Using DHCP" this was automatically enabled when I installed Mac OSX 10.1.5, when changing to "Using DHCP with manual address" solved the problem.


"I drank a lot of Buds but I don't feel any Wiser"

Oh no! Problem is back driving me crazy