Very good insight into the Alfa AWUS036H card: Sent to us by customer Troy Wilson.
If you connect the first time to any signal at all, the IP address of that connection will appear in the Alfa Utility under the "General" tab. If you connect to another connection, many times that IP address won't change from the original connection's IP even if you push the "renew" button. One must push "renew" at least 3 times before the Alfa will release and renew it's IP address - sometimes I have to push renew maybe 20 times before it will cough up its stored IP address.
As I read the internet complaints I can see that this is the logical problem that everyone has. They also can't look at an IP address and tell if that IP goes with a certain connection. The Alfa shows it's connected, and it is connected, but it often shows a connection to a certain network when in fact it has an IP address from a previous network, stuck in it. So, as people say, "it shows it is connected with a big strong signal, but I still can't get the internet." Once it has a stuck IP address, you will never, ever successfully hook up to another signal and establish internet connectivity even though you appear to be CONNECTED. The problem is compounded by the fact that almost every wireless router on the planet has an IP address of either 192.168.1.1 or 192.168.0.1. This makes it almost impossible to deal with.
Let's say you view the Alfa utility and it shows you are connected to 192.168.1.1, with subnet 255.255.255.0, and gateway also of 192.168.1.1, and everything is working well. But then you decide to connect somewhere else, except that new connection has the very same IP, subnet, gateway and DNS - this scenario happens in reality almost 50% of the time you choose to initiate a new connection. The Alfa assumes it already connected and refuses to renew it's stored IP address BECAUSE IT IS EXACTLY THE SAME AS BEFORE. Why should it release and renew? The problem only arises because radios sit on different channels - they may all have the same IP address, subnet, gateway and DNS, but now it's all happening on a different channel and a different SSID. You are connected on one layer, but disconnected on another layer. Great connection, but no internet. The release/renew scenario also changes the radio's channel and SSID. I may be hooked up to "Linksys" but my information is trying to come from that last "Netgear" connection on a channel that is now not working.
Just keep pushing "renew" and it will finally release the old IP, get its new address and channel, and the internet flows - 90% of the time. There are other times when you will have to actually hard-set the IP, subnet, gateway and DNS for the Alfa to release and renew - but this is beyond most people's abilities. This is why I have learned to associate an IP address and channel with a particular connection and one glance will tell me if I need to start pushing "renew." I use a program that tells me on what channel an access point is broadcasting.
Disabling and re-enabling the adapter will also force an IP renewal without having to go through the command prompt and the ipconfig /release /renew routine.
In my humble opinion, the Alfa hardware is superb. It uses a tried and true chip, the RealTek 8187. The software that drives the hardware is a bit less than superb. It needs to be re-written to absolutely force renewal at any cost. Complete renewal of SSID, channel, IP, and everything else - EVEN IF IT IS ALL EXACTLY THE SAME AS BEFORE. Unconditional release and renew.
I have done much reading about this Alfa product (the AWUS036H) and Google is full of people who are having problems with it. When I first got it from you guys I had my share of disappointments with it, too, but now I have learned a few tricks and am happy with it, When it does work it really WORKS - the little thing will pull in a signal from West Hell, but people are having trouble getting it to connect to those signals and/or transferring internet data.
Live on an island - I use a 19 dbi panel antenna to shoot 3 miles across the sound to hook up to some nice person who has a 20 meg broadband pipe. I have other choices, but this one is really fast. This is all done with the little AWUS036H on the other end of that antenna. All this person has is just a regular SMC wireless router provided by the cable company. Nothing fancy - and I'm sure he has only the stock little antennas on it.
Thanks for sending me that new set of cable extenders - you have my allegiance to Data Alliance!!!!!
Posted by Troy Wilson on 26th May 2019