Showing posts with label Internet Protocol. Show all posts
Showing posts with label Internet Protocol. Show all posts

Your Browser, and Your Voice Modem

Occasionally, we read odd queries in various forums

When I am browsing certain web sites, or running a specific program, my computer starts the modem and dials out. Does anybody know what is happening here?
And those of us who are used to this query reply simply
Go to Internet Properties - Connections tab, and make sure that "Never dial a connection" is selected.


Long ago, when the browser was the only Internet application on the computer that was used with any regularity, the Internet Protocol stack and the dialer were built in to the browser. Even after the IP stack became part of the operating system, Internet Explorer continued to provide the option to have it dial out, automatically, if it detected a lack of Internet connectivity being provided by the operating system and network stack.

Unfortunately, the mechanism for detecting lack of Internet connectivity, from time to time, seems capricious. The oddest circumstances may cause the browser to dial out, leading to some interesting phone bills for some computer owners.

If you have a computer with an internal modem, and you connect your analogue voice service (aka "telephone") to the modem, maybe as a backup to your broadband service, you may occasionally hear the computer chattering away, when you pick up an extension and prepare to dial out. Now, you know why.

You can still have dial capability, as a backup to your broadband service. Simply use the dialer in Settings - Network Connections when necessary, and make sure that the browser is set to "Never dial a connection". Or, if you're interested, you could get a router that uses dialup access as a secondary connection.

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WiFi Networking And Static IP addresses

When your computer connects to a WiFi access point, one of the first things that it normally does is to request an IP address, so it can connect to the router and / or to the other computers in the LAN. One of the earliest ways to stop intruders from connecting to your LAN, through your WiFi access point, was to restrict access by MAC address. A second way was to disable DHCP, and stop issuing IP addresses automatically.

Such a simple procedure - and so useful (or so thought those who tried it). Not so useful, thought the hackers when they would encounter a WiFi LAN, without DHCP to issue IP addressing. Part of hacking a WiFi LAN involves monitoring the packets for useful MAC addresses, and a small additional effort is then expended in extracting IP addresses. It's just radio.

If your neighbour, who just bought his first wireless computer, can't get an IP address when he connects to your otherwise open LAN, he can't access the Internet through your service. You're safe from him leeching your Internet service.

But what of his son, who hacks as a hobby? Once he gets past your MAC address filter, finding out what IP addresses are being used is trivial. He probably won't even notice that you disabled DHCP. And since he hacks, he's probably got nefarious intent, maybe leeching WiFi so he can hack a distant Internet server, using your service of course.

Maybe the FBI is targeting his activities, so he's borrowing your service. When they see his new IP address (your service), who gets blamed? Probably you.

Oh yeah - if you have DHCP disabled on your LAN, and you carry your laptop to your friends house, how are you going to get an IP address? Are you going to manually setup an address there? Then change it back when you come home again? Have fun. What about to your local hotspot, where DHCP is the only way that you can get an address?

I know who I would worry about, when I assess the dangers associated with Internet connectivity, and with WiFi networking. Static IP Addresses, when used as a security device on a WiFi LAN, are just another form of security by obscurity, plus inconvenience to you. Use WPA / WPA2, not WEP, and properly layered security, and forget about other WiFi security devices. Any hacker who can get through WPA (and that will happen one day) won't be fazed in the slightest by fixed IP addressing.

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