[systemd-devel] Bonding wireless and wired internet connection makes my internet really slow

[Kai Krakow]

Am Thu, 03 May 2018 14:34:34 +0300 schrieb Doron Behar:

> Hi everyone,
> 
> I'm trying to bond my wireless and wired network interfaces using
> `systemd-networkd`. Since I didn't want to put any configuration in
> `/etc/systemd/network/` I don't fully understand, this is the
> configuration I've ended up with:
> 
> 	$ cat /etc/systemd/network/10-bond0.netdev
> 	[NetDev]
> 	Name=bond0
> 	Kind=bond
> 
> ---
> 
> 	$ cat /etc/systemd/network/20-wired.network
> 	[Match]
> 	Name=enp0s25
> 	
> 	[Network]
> 	Bond=bond0
> 
> ---
> 
> 	$ cat /etc/systemd/network/25-wireless.network
> 	[Match]
> 	Name=wlp2s0
> 	
> 	[Network]
> 	Bond=bond0
> 
> ---
> 
> 	$ cat /etc/systemd/network/35-tethering.network
> 	[Match]
> 	Name=enp0s20u*
> 	
> 	[Network]
> 	Bond=bond0
> 
> ---
> 
> 	$ cat /etc/systemd/network/40-bond0.network
> 	[Match]
> 	Name=bond0
> 	
> 	[Network]
> 	DHCP=yes
> 
> ---
> 
> As opposed to the old configuration which works as fast as light:
> 
> 	$ cat /etc/systemd/network/20-wired.network
> 	[Match]
> 	Name=enp0s25
> 	
> 	[Network]
> 	DHCP=yes
> 
> ---
> 
> 	$ cat /etc/systemd/network/25-wireless.network
> 	[Match]
> 	Name=wlp2s0
> 	
> 	[Network]
> 	DHCP=yes
> 
> ---
> 
> 	$ cat /etc/systemd/network/35-tethering.network
> 	[Match]
> 	Name=enp0s20u*
> 	
> 	[Network]
> 	DHCP=yes
> 
> ---
> 
> With the 1st configuration, If I reboot, I definitely have networking
> capabilities but from some reason, after a while, browsing the web for
> example, becomes extremely slow.
> 
> How can I debug this? Are there any best practices for the simplest
> bonding configuration? What am I missing here?

Do the wifi and cable network connect to the same router? Then it
probably doesn't know about the bonding and network packets start to
travel in circles after a while.

You may be able to fix this by setting the bond mode to failover
instead of balancing. I think the mode is called "active-backup". But
usually the other end of the bond needs to know about this, too.

Another mode which may work is "balance-xor" which usually allows
attaching bonding members to different switches on the other side.

The mode defaults to balance-rr which is probably incompatible with
your setup.

BTW: Bonding may not improve throughput and even hurt latency a lot if
you combine very different types on links, i.e. wifi and cable. So
"active-backup" may be the best way to do it here.


-- 
Regards,
Kai

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