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anav
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Possible Loop Errors.

Mon Dec 03, 2018 11:15 pm

Primary Issue:

House guest noted internet lagging.
When checking my router logs I noticed the line.
"interface: warning - eth2: bridge port received packet with own address as source address (mac XX.YY.ZZ etc..) probably loop"

The funny thing is that there is no lease with that MAC address that I can find with that on the router, and the mac is NOT the mac of the eth2 port either..........


Secondary Issue,
I am getting many many offering lease without success entries.
How can I cut down on those???
Is that the fallout from making IPs static as opposed to keeping them dynamic??

It appears one if not both of my CapAC are giving me issues at the moment as well. hmmmmmm?
 
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vecernik87
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Re: Possible Loop Errors.

Tue Dec 04, 2018 8:28 am

Just to make sure before any assumptions are made - the MAC address does not belong to any interface in your router?
Can you check it with your
/interface bridge host print where mac-address="XX:YY:ZZ"
?
 
anav
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Re: Possible Loop Errors.

Tue Dec 04, 2018 2:21 pm

Just to make sure before any assumptions are made - the MAC address does not belong to any interface in your router?
Can you check it with your
/interface bridge host print where mac-address="XX:YY:ZZ"
?
Hey V87, you were right, its the mac address of the bridge. Does that help diagnose what happened??
It hasnt re-occurred today yet.
 
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Steveocee
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Re: Possible Loop Errors.

Tue Dec 04, 2018 2:23 pm

It can be helpful setting a MAC address for your bridge. I generally tend to use ether1 MAC as a template so if the MAC is 00:01:02 I will increment the second character by 2 so it becomes a made up MAC of 02:01:02 and this has resolved these situations before.
Steve "Steveocee" Carter
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anav
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Re: Possible Loop Errors.

Tue Dec 04, 2018 7:46 pm

Hey Steve, can you elaborate?
My bridge has a mac assigned, why would one need to assign it a different one?

Or
Are you saying that each interface to bridge interaction should see a different bridge mac address and if so how to do that???
 
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vecernik87
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Re: Possible Loop Errors.

Wed Dec 05, 2018 4:20 am

Does that help diagnose what happened??
It does not diagnose the issue but it is necessary step for diagnosis.

I definitely agree with @Steveocee - try to change the bridge MAC to something definitely unique. (make sure with bridge hosts before that, if the MAC is really unique and there is nothing even barely close to it)
That will allow you to confirm, whether you are really experiencing loop or if it is just some device with accidentally same MAC (very unlikely but better to make sure)

If it keeps happening even with new unique MAC on bridge, then it is clear you really have a loop somewhere. That typically happens with misconfigured VLANs and bridges. If I remember correctly, you were experimenting with this recently. It could, however, be as well real physical loop or some misconfigured device causing loop (e.g. laptop connected to wifi and eth at the same time with those interfaces bridged)
If you haven't read it yet, check typical layer2 misconfigurations - maybe you will find some example applicable to your situation.
Unfortunately this area of expertise (vlans/(r)stp) is beyond my knowledge. I am slowly learning and testing these things in lab but I am not really confident and I haven't had balls to apply it to production environment yet. (Once I did and the network didn't like it at all...)
 
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Steveocee
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Re: Possible Loop Errors.

Wed Dec 05, 2018 10:31 am

Hey Steve, can you elaborate?
My bridge has a mac assigned, why would one need to assign it a different one?

Or
Are you saying that each interface to bridge interaction should see a different bridge mac address and if so how to do that???
By default the bridge uses auto-mac which grabs the MAC address of the first ethernet port it sees. It's not great practise to do this as if you remove a cable from that port the admin-mac will change on the bridge. Incrementing the MAC of the ethernet in the way I showed effectively guarantees you will not have a duplicate MAC address in your network and will remove the uncertainty of if traffic is coming from ether or bridge and being sensed as a loop.
Steve "Steveocee" Carter
PC Gamer, Airsofter, MikroTik Nerd
My Website - My MikroTik Tutorials
 
anav
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Re: Possible Loop Errors.

Wed Dec 05, 2018 2:02 pm

Good info all the way round.
I suspect it may have been this.......... .g. laptop connected to wifi and eth at the same time with those interfaces bridged.
It has not re-occurred yet.
 
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Steveocee
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Re: Possible Loop Errors.

Wed Dec 05, 2018 2:23 pm

Good info all the way round.
I suspect it may have been this.......... .g. laptop connected to wifi and eth at the same time with those interfaces bridged.
It has not re-occurred yet.
PEBKAC ?
Steve "Steveocee" Carter
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My Website - My MikroTik Tutorials

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