I managed to get the TL-WN722N(US) version 3 router to run on a laptop running Ubuntu 16.04. I cannot get it to run on a desktop running the same OS. I chatted with Tech support and they indicated they only support kernels to 4.4.3.  (I have it working on 4.15 on my laptop.) So I down-graded to that.  When I bring up the adapter I can see wireless connections in my house, and most importantly. the router, as shown by a iwlist scan.  I have used both the adapter supplied by TP-LINK as well as separately compiling one from RealTek.  I have been attempting to follow the directions supplied in the Linux Installation guide provided by TP-LINK.

 

The problem is that pinging the router is met with "Network is unreachable".  What mystifies me is that the adapter is seeing the world, and the machine is seing the adapter, so what do I have to do to get the machine to see the world?

 

I have tried both using network-manager and manual configuration to no avail.

 

If anyone has sucessfully gotten this adapter to work on Ubuntu as a simple plug in, I would deeply appreciate any direction you can give me. I feel it is likely a problem with the networking configuration so I supply some salient information below. dhclientf does not retrieve an ip address as currently configured.

 

Here is the result of ifconfig for the wireless adapter. Note the ip  and bcast addresses was manually assigned. since dhcp is not working.

 

wlx503eaa7cbbbf Link encap:Ethernet  HWaddr 50:3e:aa:7c:bb:bf  
          inet addr:192.168.0.20  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::523e:aaff:fe7c:bbbf/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2638 errors:0 dropped:1895 overruns:0 frame:0
          TX packets:560 errors:0 dropped:37 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:562741 (562.7 KB)  TX bytes:296803 (296.8 KB)

 

iwconfig gives the following:

 

wlx503eaa7cbbbf  IEEE 802.11bgn  ESSID:"XXXXXXXXXX"  Nickname:"<WIFI@REALTEK>"
          Mode:Managed  Frequency:2.462 GHz  Access Point: 54:65:DE:65:D0:90   
          Bit Rate:54 Mb/s   Sensitivity:0/0  
          Retry:off   RTS thr:off   Fragment thr:off
          Encryption key:676F-326E-6F77-7477-6F00-0000-00   Security mode:open
          Power Management:off
          Link Quality=87/100  Signal level=-44 dBm  Noise level=0 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

 

Here is my interfaces file:

 

# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

auto wlx503eaa7cbbbf
iface wlx503eaa7cbbbf inet dhcp
netmask 255.255.255.0
network 192.168.0.0
gateway 192.168.0.1  # obtained from another machine on the network
wpa-driver wext
wpa-ssid XXXXXXXXXX  # matches the ssid above
wpa-ap-scan 1                               # Identical to what is working on my laptop
wpa-proto RSN                              # ""
wpa-pairwise TKIP                      # ""
wpa-group TKIP                            # ""
wpa-key-mgmt WPA-PSK        # ""
wpa-psk  ... confirmed correct ...  same as belo

 

and my wpa_supplicant.conf file:

network={
        ssid="XXXXXXXXXXXX"
        #psk="YYYYYYYYYYY"
        #psk=8c69c0e3b270b559d21fa82265ea909ac68d0bb6849bcc6cf8238a13e03989d7
        psk=fbe5c7128b52836d4469c628e217e562b6817bf8cfd7afa74cc302bf6238be14
        scan ssid=1
}

 

When I run dhclient it gets stuck in an infinite loop looking for a connection and never finding one.

 

This is my first time in 30 year having to post a request for help.  I hope it is something trivial wrt the netwoking. A ping 192.168.0.1

gives "Network is unreachable".

 

The kernel is 4.4.3, which supposedly works.

Thanks in advance to anyone who may reply.