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Hi all.
One of the main issues that an OSPF link does not finish negotiation is because of MTU mismatches. So that I have configured the MTU of the interfaces that handle the OSPF traffic to mach that of the remote interfaces. So far so good and the OSPF adjacencies work ok, and we have routes and all fine.
But when the pfSense VM restarts for any reason, OSPF does not comes up (because MTU mismatch errors) until I go to the interface and save it. No changes in any field; only go to the button and save it. Then OSPF looks like it reads the MTU and starts working fine again.
And this is a problem because each time that we have a restart someone has to login to the pfSense device and save the interface. Until that moment there is no traffic between sites because there are no routes.
Can anyone help with this?
pfSense version 2.4.2.
Thanks.
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I had this issue too with 2.4.4-p2.
The fix is to ensure the VTi interfaces are set to an MTU of 1400 - nothing else works. This survives a restart and works great.
Interfaces / "VTi interface name" (ipsecxxxxx)
MTU 1400
MSS 1400 -
I've raised a bug report on this issue too.
[https://redmine.pfsense.org/issues/9528](link url) -
@nzkiwi68 Thanks for your tip.
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@nzkiwi68 Cannot beleive that no one had done it already
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FYI- FRR 0.6, now available on 2.5.0 snapshots, also has an option on interfaces to ignore MTU, which can also work around these sorts of issues.
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