CentOS - Jan 2017 - Reliable way of having both LAN and WIFI on headless box

Once again I am building a headless Centos 7 box that needs to reliably be on 
both the LAN and WIFI network at all times.  Amongst other things it's going
to be an AirPrint bridge enabling IPads to print to printers on a different 
VLAN.

I have asked about this before and got a solution working using nmtui to set 
up both the LAN and WIFI interface, and activate them.  However, the WIFI 
link is unreliable. Sometimes it doesn't activate, or after a while 
de-activates.  Sometimes it doesn't even appear in nmtui to enable me to 
activate it.

Can anyone help me with how I can set up a more reliable server.

Thanks

Gary

On Mon, 9 Jan 2017 16:05:16 +0000
Gary Stainburn wrote:
> However, the WIFI 
> link is unreliable. Sometimes it doesn't activate, or after a while 
> de-activates.  Sometimes it doesn't even appear in nmtui to enable me
to
> activate it.
That sounds like a weak signal from your wifi transmitter.

-- 
MELVILLE THEATRE ~ Real D 3D Digital Cinema ~ www.melvilletheatre.com

On Mon, Jan 9, 2017 at 12:04 PM, Frank Cox <theatre at
melvilletheatre.com>
wrote:
> That sounds like a weak signal from your wifi transmitter.
>
Or signal interference.  Where is the antennae located on the server?  Ran
into signal issues with antennae which were tucked behind the server before.

On Monday 09 January 2017 16:05:16 Gary Stainburn wrote:
> Once again I am building a headless Centos 7 box that needs to reliably be
> on both the LAN and WIFI network at all times.  Amongst other things
it's
> going to be an AirPrint bridge enabling IPads to print to printers on a
> different VLAN.
>
> I have asked about this before and got a solution working using nmtui to
> set up both the LAN and WIFI interface, and activate them.  However, the
> WIFI link is unreliable. Sometimes it doesn't activate, or after a
while
> de-activates.  Sometimes it doesn't even appear in nmtui to enable me
to
> activate it.
>
> Can anyone help me with how I can set up a more reliable server.
>
> Thanks
>
> Gary
The server I was using was an old workstation PC that I re-used for this 
purpose.  I have now purchased brand new kit and done a clean install.

This box has now been running fine for a few days until this morning, when the 
WIFI dropped off again.  To investigate this I have had a look 
in /var/log/messages and I have found lots of entries.

At the bottom is where I re-activated the interface. 
Above that there are lots of entries where it toggles between inactive and 
disabled.
Above that at 09:33 there is an incident, and before that all looks normal.

I have posted the log here:

http://www1.ringways.co.uk/var_log_messages_WIFI.log

Can someone give me a clue how to fix this.

Also, it was suggested that I use nmcli in a cronjob to re-activate it if it 
drops.  I can check to see if it's still active by 'grep'ing the IP
address,
but I don't know the nmcli to re-activate an existing WIFI connection.

Can anyone help here too, just in case I can't fix the real problem

On Fri, Jan 13, 2017 at 12:33 PM, Gary Stainburn <gary at ringways.co.uk>
wrote:
>
>
> Also, it was suggested that I use nmcli in a cronjob to re-activate it if
> it
> drops.  I can check to see if it's still active by 'grep'ing
the IP
> address,
> but I don't know the nmcli to re-activate an existing WIFI connection.
>
> Can anyone help here too, just in case I can't fix the real problem

I have a wireless connection named "AndroidAP-notepro"

So I can run

# nmcli con show --active | grep AndroidAP-notepro
AndroidAP-notepro  62d0fc1f-91b8-4c07-baf0-323cf1c108d1  802-11-wireless
 wlp3s0
#

You can check exit code and number of lines.
If number of lines is 0, it means the connection is not active and you can
try to activate it and get exit code of the command

# nmcli con up AndroidAP-notepro

Also, it could be useful to know what value you have for
"connection.autoconnect" for this connection.
If it is yes, in theory it should automatically reactivate when it returns
available.

In my case my AndroidAP-notepro connection is to be manually activated and
in fact I have

# nmcli con show AndroidAP-notepro | grep connection.autoconnect:
connection.autoconnect:                 no
#

In case you also have autoconnect set to no, If you don't have a gui you
should be able to set it up with

# nmcli con mod AndroidAP-notepro connection.autoconnect yes

HIH,
Gianluca