Looking to know your thoughts on MTU settings for provider networks.
We run a decentralised core style setup - a PtMP wireless network from multiple tours. Each tower has an RB1100AHx4 or an RB3011 at the bottom, these routers terminate all local PPPoE sessions and then run OSPF between them using PtP links.
Recently one of our backup paths we are required to use a GRE tunnel to get to the internet. With MTU Path discovery - the GRE tunnel sits at 1426 MTU inside, and we use Clamp TCP MSS on the tunnel. All of our links run at 1500 then PPPoE clients are running at 1480.
What is your recommendation for MTU settings? Should we bring the core network up above 1500, even into jumbo range? Or will that cause more issues? Should we leave PPPoE clients at 1480?