@KarstenI , this issue is sort of like hydra as in, we fix one instance of the issue, can no longer reproduce it, and for some reason, it keeps coming back one way or another. You are right, that this was originally seen in switch 11, but was rare. This issue started getting reported more often in later versions which led to the issue being investigated further and resolved in MS 14.28. The changelog message for this fix was: In rare circumstances, the next hop VLAN is incorrectly modified for existing OSPF SVIs when a new SVI is added which will also participate in OSPF. A reboot will correct this (present since MS 11) Shortly after, additional reports of similar issues were reported. These were resolved in MS 14.31. Changelog message for this: Modifying SVIs on switches could cause the next-hop VLAN to be incorrectly set; which would result in routing outages The most recent occurrence, that is impacting MS 14.31+ versions is yet again, another instance of this issue. The MS 14.32, along with MS 15.2+ changelogs have been modified to have the following issue in the "Known Issues" section: In rare scenarios, changes made to SVIs may result in connectivity loss for one or more SVIs until reboot (present since MS 14.31) This issue is actively being investigated, with hopes that it will make it into a future release soon. Hopefully, I have been able to add a bit of additional clarity around the troubles you are facing.
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