No subnet declaration; Can't open /var/lib/dhcp/dhcpd.leases for append

A publicface at
Sun Jan 28 18:19:43 UTC 2018

On 01/28/2018 01:38 AM, Simon Hobson wrote:
> A <publicface at> wrote:
>>> OK, so this box is your gateway, AP, etc, etc. In that case I believe that your setup is fundamentally broken - you have TWO SEPARATE networks (one wired, one wireless) running the same subnet.
>> Yes, that's how I was told to set it up by a helpful individual.  I was told since it was one subnet, no routing would be needed.  The wireless & wired interfaces would be bridged.  Seemed reasonable.  It sounds like you are suggesting exactly the same thing so "fundamentally broken" seems a bit harsh.
> Key thing there is BRIDGED - ONE bridge interface with ONE address in the subnet, more than one port assigned to the bridge. What you have is NOT a bridged network, it is two SEPARATE networks with the same subnet - it's is fundamentally broken and will NOT work (at least without a lot of fudging around to work around the brokenness.

I've never setup a bridge before and got the syntax for brctl wrong and 
that's what caused the config you saw.  I thought I was telling it to 
bridge wired & wireless faces, when apparently it was doing something 
else without telling me so.  I was doing: brctl addif br0 enp4s5 wlp2s0 
which I thought linked the two faces.  It apparently added the enp4s5 
and ignored the wlp2s0.

Once I finally realized that yesterday and corrected the syntax it will 
not add the wireless interface as a port.

# brctl addif br0 wlp2s0
can't add wlp2s0 to bridge br0: Operation not supported

And just to be complete:

# brctl addif br0 enp4s5
device enp4s5 is already a member of a bridge; can't enslave it to 
bridge br0.

# brctl addif br0 enp6s0
That one succeeds, because like 4s5, 6s0 is a wired NIC.

That's after changing "manuel" to "manual" just in case that was a 
relevant issue.

Therefore as I can't add the wireless face as a port, I'm unable to 
bridge using brctl from the bridge-utils package.  So unless there is 
another virtual bridge package, bridging won't work.  Unless of course 
I'm still doing it wrong which is always a possibility.

>> I removed the bridge because I was unable to reach the Internet from yellow (nor blue).  And that is how things stand now.  Bridge up, Internet down.  Bridge down, Internet up.
> OK, so there's a different issue there, and it'll be to do with your masq setup.
> You probably need to take a step back and get the basics working first. Forget your DHCP for the moment and statically configure some clients - that way you can work on one issue at a time.

I had everything working including DHCP except blue->Internet. After 
getting that far by myself, someone redirected me to a different setup 
that as you've pointed out, is broken, starting with the bridging 
package itself (no wireless support).

So proceeding further down this path is not possible afaik. Therefore, 
also considering the fact that bridge-utils is considered deprecated, 
I'm going to go back to my original setup of 2 separate subnets and 
route them as I originally intended. I got sent down the garden path, 
thanks for helping bring me back!

There is apparently another way to do this using systemd I stumbled on, 
but I have not looked into it, bridge-utils seemed to be the fastest way 
forward.  Sadly, it was not.

Thank you for all your insight and help, it is greatly appreciated!

By the way... do you (or anyone) know of a general networking mailing 
list?  Thanks again!

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