VLANs having same mac address causing flapping error on cisco switch
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You generally see this type of issue in a HA setup, i've seen it many times with an all Cisco setup and HSRP.
Are you running a HA pair, if you are there probably is a connectivity issue between the pair.
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I am using 7 ports on the marvell switch on the xg7100 connected to my cisco 3560.
eth2-3 are vlan 5
eth4-6 are vlan 10
eth7-8 are vlan 30I wanted to setup a lagg for each vlan, but since the xg7100 marvell switch does not support lacp, I had to throw everything to basic load balancing. I have the cisco ports set up within channel groups, and the pfsense ports I had to manually add them to their own lagg groups through ssh using etherswitchcfg.
As far as I can tell, it works properly, on the switch it shows the proper ports per vlan have bundled.
The 3560 will have the flapping error if I leave each vlan mac addr the same (as shown in ifconfig when run through ssh on the xg7100).
I can draw something up later today to better illustrate.
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You should be setting up the load balance laggs using the web gui and changing the lagg numbers by clicking on the lagg number in Interfaces > Switches, Ports. Just use a unique number for each group.
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I should be, but when I go to add a LAGG in the gui, the ports on the marvell switch do not show up. So I cannot make a LAGG with the ports I want to use.
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Screenshot please. That should not be the case. Unless maybe something you did under the hood is preventing that from working any longer somehow.
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ix1 is only the 10gig sfp+.
Eth1-8 are not shown. -
No.
Interfaces > Switches, Ports
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If you are referring to inputting the lagg id manually there... that instantly destroys the web gui and requires the firewall to restart.
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Don't do it on a port you are trying to manage the firewall from. Same way you would not make a change to a switch port you are managing the switch from.
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Sure, I understand that.
Referencing back to the original question, the xg7100 has the same MAC addr assigned to eth1-8 on the marvell switch, right?
So wouldnt creating separate LAGGs across that marvell switch cause a downstream switch to see the same mac for multiple channel groups, then cause the flapping error?
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No. MAC Address tables should be separated in the switch by VLAN/broadcast domain.
The MAC address being seen by the switch is actually the MAC address of the lagg0 created by ix2 and ix3 on the pfSense software on the uplink.
Layer 2 switch ports do not have individual MAC addresses. The have MAC address tables and forward traffic between different MAC addresses in the same broadcast domain.
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Okay, but the downstream switch has its own mac address table and when the vlans all show up as the same mac, I'm pretty sure that causes the flapping error.
I'm not 100% sure what the flapping error exactly is, but I don't really see what else could cause the error since it stops when I change the macs for the vlans.
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Perhaps the load balance lagg/port channel in that switch is incompatible with the load-balance lagg in the Marvell chipset. Really hard to tell from here.
The port channel should allow input from any MAC on any of the ports at any time.
Are Po1 and Po2 in your OP members of the same port channel? Is the port channel properly-configured?
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Your original post showed the MAC as switching between interfaces. That wouldn't normally happen with VLANs.
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That's what Im trying to explain, that the switch thinks its switching because the vlans all show up as the same mac.
My original post showed the switch saying it was switching, but if all the interfaces have the same mac, how would it know it was switching?
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Because the same MAC is showing up on the same VLAN on two different ports (or port channels in this case.) It is not just the same MAC address, it is the same MAC address on the same VLAN. You should get the same log moving any host from one port to another, though it might be suppressed because of the link down clearing the CAM table when you move it.
Both of those in your OP are VLAN 1, not two different VLANs.
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Im not sure the vlan1 makes a difference. Vlan1 is not in use on my switch, it is simply the default vlan and since the trunk ports on the switch cant have a vlan assigned directly, they only can have allowed vlans assigned, it shows up in the logging as vlan1.
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@erasedhammer said in VLANs having same mac address causing flapping error on cisco switch:
My original post showed the switch saying it was switching, but if all the interfaces have the same mac, how would it know it was switching?
I think you may be getting things confused. The MAC address refers to the original interface. I assume that's the pfSense box. Switches do not change the MAC address of frames passing through them. So, no matter where that frame goes, the MAC address will remain the same. Switches then learn which interface is closest to that interface, though spanning tree can change that, when the configuration changes.
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Okay, so then my question is why doesn't the xg7100 have the ability to assign macs to the switch ports on the marvell?
Is that a software or hardware limitation? -
Because Layer 2 switch ports don't have MAC addresses.
Please post your current etherswitchcfg output.
And the port channel configurations on the switch and what ports are connected to what.
Thanks.
