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How to obtain IP address of wifi access point on different subnet?

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So my laptop is connected to a wifi access point that has no security configured. It is setup on a different subnet and the person that setup it's IP address can no longer remember what he did. The simplest answer would be reset the AP to factory default but for the sake of argument lets assume that isn't an option and set that aside. It seems like there should be a way to figure out the IP address of the AP. I even have its MAC address that I got off of the bottom of the unit. Is there a way that I can about doing this?

BTW it is my customer's AP here so there is no hacking or troublemaking going on, just trying educate myself.

asked 20 Jun '14, 09:19

Aaron%20Hartley's gravatar image

Aaron Hartley
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accept rate: 0%


2 Answers:

1

Is there a way that I can about doing this?

O.K. I assume the device is configured to work as a real AP and not as a router. If it was a router, it will be the default gateway for all connected clients, so the IP of the AP would be your default gateway (DOS box: route print) as soon as you are connected to the device.

However you said AP, so here we go:

  • Connect the AP network interface (LAN) to a switch
  • Connect your sniffer PC to the same switch (same VLAN)
  • Start Wireshark
  • power-cycle the AP

Now look for ARP (gratuitous), broadcasts, other frames. If you're lucky, the AP reveals it's IP address in one of those frames.

Regards
Kurt

answered 21 Jun '14, 17:16

Kurt%20Knochner's gravatar image

Kurt Knochner ♦
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accept rate: 15%

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Hi Kurt thanks for responding. You draw an important distinction that I forgot to mention. The AP isn't really an AP but a wireless router, a linksys wrt54g. However, the wrt54g is not the gateway for the network, which is a comcast device. I'm assuming the router's DHCP has also been turned off because otherwise the network would be going bonkers (aside from not knowing the IP address of the wrt54g and having unsecured wifi the network otherwise works fine). Aside from scanning the network I also ran IP scan against the default IP for that device, 192.168.1.1 and it turned up nothing.

answered 23 Jun '14, 10:19

Aaron%20Hartley's gravatar image

Aaron Hartley
11113
accept rate: 0%