VXLAN over wireguard. Unexpected MTU reset bug(?) (PFSENSE+)
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Environment:
OS/Software: pfsense+ latest
Setup: VXLAN over a WireGuard parent interface (VXLAN MTU requires 1370).
The VXLAN interface is assigned to a bridge.
The Issue:
The VXLAN MTU holds at 1370 correctly inside the bridge. However, if I make any change to the WireGuard interface's MTU, the VXLAN interface automatically resets its MTU to 1450 (Visible in Status > interfaces).Current Workaround:
To restore the correct 1370 MTU on the VXLAN interface, I have to completely remove the VXLAN interface from the bridge, save the configuration, and then re-add it. -
Hmm, resaving the VXLAN doesn't set the MTU again whilst it's still a bridge member? You are setting the VXLAN MTU to 1370 in the assigned interface config I assume?
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@stephenw10 Yeah, it doesn't or at least didn't on my server, I can test that again outside of business hours. Yes, I am setting the VXLAN MTU to 1370 in the assigned interface config. No matter what though, it shouldn't be resetting to 1450 because that is not configured anywhere except as a default value
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What do you have the WireGuard tunnel MTU set to?
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@stephenw10 1420
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Hmm, well that seems like a problem. I wonder if the bridge code is overriding the VXLAN parent. Let me do some tests...
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@stephenw10 VXLAN tunnel does work perfectly fine when the mtu is set up correctly
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@stephenw10 it also resets to 1450 on reboot, however I was wrong saving the interface while in bridge does work
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@stephenw10 Is there any update on this
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I have been waiting for a long time at this point, I use this feature regularly, and it still breaks every so often randomly because the mtu resets. I will submit a bug request soon
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Yeah open a bug report. It's always better to track it that way anyway.
