[SOLVED] Can't connect to destination address using public key TASK ERROR: migration aborted

Summarizing / clarifying:

This below finally worked for me after many failed tries following the various helpful but now disorganized suggestions in this thread.

# ssh into each node with (replace the 2 variables appropriately)
ssh -o "HostKeyAlias=NODENAME" root@NODEIP

# run on each node
cd /root/.ssh
mv id_rsa id_rsa.old
mv id_rsa.pub id_rsa.pub.old
mv config config.old
pvecm updatecerts

In my setup:
* two nodes are on the same L2 switch
* the two nodes have different PVE versions 8.1.x and 8.3.x

Good luck
 
# ssh into each node with (replace the 2 variables appropriately)
ssh -o "HostKeyAlias=NODENAME" root@NODEIP
I finally got migrations to work despite all other things, I missed the mention to the above method method in previous comments, but I can confirm this fixed my Host Verification problem as well.

I did not have to do the below however, and honestly I'm a bit uncertain if I even need to at this point. If I need to do it from a security standpoint I will, but honestly I don't want to break something that is working.
# run on each node
cd /root/.ssh
mv id_rsa id_rsa.old
mv id_rsa.pub id_rsa.pub.old
mv config config.old
pvecm updatecerts
 
I'm struggling with this as well on a new cluster. Following the steps y'all took I got migration to work on one interface, but not the 10G interface I'd rather have it using. ssh -o "HostKeyAlias=myhost" root@myhost-10G-network-address doesn't work, and reducing the MTU values on that interface's bonds didn't help either.

Additional complexity I may have that most don't.
  • Management/cluster interface is a bridge
    • On top of a bond of 2.5G nics
  • Main interface is a bridge
    • On top of a bong of 10G SFP+ nics
  • When I configured the cluster I told it to use the management interface as the primary cluster interface with a priority of 0, and the 10G interface as an additional interface with a priority of 1.
Any thoughts?
 
Never mind - @JerryLees had it. After reading his post I changed the MTU to 1500, but I'm still new to Proxmox (well, back to it after years) and I forgot to click apply. Working now.