physical location of AP

Yawn. I posted an answer to your previous variation on the same question. See:

This homework assignment seems to come up a lot. There's really no way to know unless you know the entire topology of the network.

He also doesn't have a very clear description or understanding of the problem.

My guess(tm) is that he wants to play TDOA (time difference of arrival) direction finder on the internet. This has been done before and is actually quite easy if you make some rather marginal assumptions. If you assume that:

1. A ping return comes back via the same route that it is sent.
2. Latency for a given ICMP echo responder is constant.
3. Latency on backbones is fairly constant over short periods of time.
4. The router doesn't delay ICMP or UDP echos using QoS.
5. You have a ping with better resolution than the usual 1 msec.
6. Whatever else I forgot.

What's necessary is to ping the IP address from a variety of distant locations. I watched it work at a local university to locate roaming hackers and student illegally deployed servers. By mapping the ping times from various nearby known locations, the unknown responder can be found by comparing the patterns. I was amazed to see a solution converge in less than a second. It's not foolproof and requires some tweaking and guesswork, but it does work.

As for identifying the access point in use, that can't be done with simple tools from the internet (WAN) side. The local router/firewall will block most probes aimed directly at the AP (which is on the LAN side of the router). If there's any information to be found on the WAN side, it must be sent (initiated) by the client or access point and not polled from the internet (WAN) side.

Hi,

I got a new project on WIFI technology. I am facing a problem. The

problem is when user is accessing my desktop application through

internet. I have to identify which Access point he is using. In other

words I want to find out the current physical location of the member.

Is there any way to find out?

jiten

And if the user's router does not respond to pings, wouldn't that also defeat the triangulation technique described in the first paragraph above?

Correct. It certainly would. Some possible workarounds.

1. Use UDP ping (udps) instead of ICMP ping.
2. Use arping instead of ping.
   formatting link
   doesn't work through routers. It works nicely on University and ISP networks that are not broken up by routers.
3. ping the nearest gateway router. It won't locate the user, but will certainly locate how they connect to the internet.
4. For managed routers, use SNMP ping. Even if you don't have the SNMP community name, the NACK from a failed open can be timed.
5. A few more I don't wanna talk about.

I've found that most wireless hot spot routers do respond to pings as whomever is managing the hot spot wants to know if it's up or down.