[SOLVED] br0: received packet on eth0 with own address as source address


danioj

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This is not really a support request more a support note for any of those people who run into the same issue. I have 3 LAN ports on my motherboards for each of my Main and Backup Servers (so I don't have to repeat myself again and flood the forum with repeating text - please see my Signature for full details of the setup). I run them both on the same Gigabit switch.

 

I plugged each of the ports into the switch last weekend in preparation for enabling bonding on both servers. Things got in the way and I never did enable it. I didn't think having all three of the LAN ports (on each server) into the switch would be an issue. I was WRONG!

 

I started too see the logs of my router and both servers fill - AND I MEAN FILL - with similar to the following:

 

br0: received packet on eth0 with own address as source address

 

MORE importantly it was crashing my wired network. Just down. Nothing would come back up or be accessible until I unplugged on / both the unRAID servers (which incidentally was how I isolated the issue to begin with).

 

I tried to debug it and I was thrown all over the place by what I found on the web. Some saying it had to do with similar ranges of MAC addresses of VM's, cheap hardware etc BUT it turns out it was something much simpler AND to top it off unRAID HELP solved it for me .....

 

I SHOULDN'T have plugged the LAN ports into the switch without having first enabled bonding. Here is what unRAID's help says:

 

Bridging is a feature that combines all of your physical Ethernet interfaces into a single logical network segment. If bonding is also enabled, the bridge sits on top of the bond; this is useful for VM configurations.

 

Caution: if bonding is also not enabled, do not connect two or more ethernet ports to the same switch unless you have STP enabled and the switch supports STP (most consumer switches do not).

 

Doing so will cause an "ARP broadcast storm" and can bring down your entire network (unplugging all sever ethernet ports except one typically will restore your network).

 

To be fair it was RANDOM that I stumbled on it. I decided that rather than debug until the later hours of the night - I wanted a Wine - So as a try at a quick solution I'd just enable bonding as I was planning and perhaps this issue would go away. Only through reading the HELP to get bonding going did I stumble on that nugget.

 

Hope it helps someone in the future.

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  • 1 year later...

I've been seeing this error in my logs since rebuilding my server with new motherboard plus PCI NIC I also had used with the old MB for bonded network interface. The error didn't affect my wired network noticeably for other use still really annoying to see the huge number of log entries. I found I was able to get it to go away by disabling, then re-enabling, network bonding in UnRAID network settings.

 

BTTW The truncated error in the log looks like this:

received packet on eth0 with own address as sour

 

Sour indeed. ;-)

 

 

Edited by lewcass
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