Broken On Extender - New Symptoms?

  • 1
  • Problem
  • Updated 3 years ago
IP problems when putting the radio on a wifi extender have been discussed but I think I have some new symptoms that lead me to believe the radio is not at fault but the SDR software. Here's my reasoning.

I have a reserved address for the radio. Running Wireshark I can see when the radio boots it requests the IP and it is granted as expected.

When I run ping -t (radio's reserved address) from my laptop I see it responding when powered up and not responding when the radio is powered down. I did several power cycles and removed the Ethernet connection to verify this. The radio clearly has the correct address.

Can someone that has this problem verify they have the same ping results?

Start SDR... It says a radio is there but it shows the self-assigned address.

My contention is that the radio seems to be doing all the right things and the software is the problem. I couldn't understand why, if I started up the software first, that a radio would pop up in the software with an IP that is not even on the 192.168/16 subnet. I shouldn't have been able to see it. I think the software is latching on to a previous IP that was assigned to the radio and not recognizing the IP the radio tells it it has.

Of course I have no source code or anything to see what the software is doing. Eventually, after numerous reboots and waits in between, the software does recognize the correct address.

This isn't not fun.

Kevin - K4VD
Photo of Kevin N4TT, Elroy

Kevin N4TT, Elroy

  • 931 Posts
  • 271 Reply Likes

Posted 3 years ago

  • 1
Photo of George Molnar, KF2T

George Molnar, KF2T, Elmer

  • 1629 Posts
  • 589 Reply Likes
Hi Kevin, sorry you're having a problem -- network troubleshooting can lead to hair loss!

I am running my 6500 (and whole 2nd floor shack) on an Airport Extreme set up as a wi-fi extender. The fiber modem and wi-fi router are downstairs. Like you, I have a reservation set in DHCP for my Flex, and for my desktop PC (Mac Pro). 

Here is my ping data:
20 packets transmitted, 20 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.144/0.236/0.287/0.042 ms

All seems good. 

Your rig broadcasts its presence on the network, so SSDR may "see" it but not be able to get connected if your PC is on a different subnet, or if your firewall settings are too tight. Is your PC on Can you try making a DHCP reservation for both the Flex and the PC? 

And you're sure you're using the right NIC, right? I got bit by that once - trying to connect through a port that wasn't connected raised my blood pressure some.

Good luck!

Photo of Kevin N4TT, Elroy

Kevin N4TT, Elroy

  • 931 Posts
  • 271 Reply Likes
Thanks George. I'm hoping someone with the problem can verify my findings. I still assert the SDR application may be at fault, not the radio, not the network, not the extender.

I can eventually connect after a bunch of reboots. The radio and the PC are both plugged into the extender. The PC has no problem getting an IP and, if my testing is any indication, the radio has no problem getting an IP. The problem is the software sees the radio (it shows up in the SDR startup window) but has a bad (self-assigned) IP address. After a bunch of restarts of the software it eventually picks up the radio's IP address.

I see the radio constantly broadcasting its presence on the network:

Eventually, after numerous application restarts the SDR app actually gets the IP correctly...

Note the timestamps when SDR finally got around to recognizing - the radio. Not the IPs - same subnet.

I still believe the application is at fault here and not the radio.

For someone else that is having this problem... please run ping -t <reserved IP> starting with the radio powered down. You should see responses once the radio boots up enough even if SDR doesn't recognize the radio. This shows me the radio is online and waiting on the app.
Photo of James Madden

James Madden

  • 187 Posts
  • 11 Reply Likes
This is a problem for me to on my initial 6300 and now on my 6700. If I power cycle twice the proble goes away. If I power cycle 3 time the problem is no longer there. If I restart my computer the problem returns. The valid up address is If the problem is manifesting and I have a defaulmipmaddress showing in sdk I can not ping the radio. If I power cycle the radio the problem goes away.
Photo of Kevin N4TT, Elroy

Kevin N4TT, Elroy

  • 931 Posts
  • 271 Reply Likes
Thanks James. Everything seems to be close to the symptoms I saw except the ping. If I read it right, you could not ping your radio until the SDR software was able to reach it. I was able to ping.

I'm not ready to reboot yet as it's working at the moment but I'm going to retry my tests later and see how reproducible they are. I had hoped I was on to something.