Solo mining and inbound 8333 connections

[tom22022]

If you solo mine and actually solve a block, does it make sense to have a large amount of inbound connections configured?  Or is the only concern outbound connections?

The idea being if you actually solve a block, you need/want to tell the bitcoin blockchain world about it as quickly as possible before another miner solves a block within seconds of you.

For example, how would a large pool handle their inbound and outbound connections?  On Bitcoind 0.21.0, if you are nat'd behind a router, you can only initiate connections outbound to the world and I believe on this version the max is 10 outbound.  But if you open port 8333 on your router, you will start seeing inbound that exceed 10, so far I am seeing 25.

But which is more important for broadcasting to the world, outbound?  Is the only advantage of inbound to run a node for others to sync their blockchain databases?

Thanks

[kano]

The most important point would be that you are (inbound or outbound) connected directly to the bitcoin of multiple major pools.

Bitcoin worldwide block distribution is not fast when it has to hop from one bitcoin to the next.

You need the large pools to be working on your block as quickly as possible, 100-200ms after you find it.

For most, if not all, that is next to impossible with a home setup.

The result of not being directly connected to major pools, of course, is the MUCH higher risk of your block being orphaned.

[NotATether]

But which is more important for broadcasting to the world, outbound?  Is the only advantage of inbound to run a node for others to sync their blockchain databases?

You need at least some inbounds open so that you can detect if somebody already solved the block you're trying to find so that you don't waste precious milliseconds on it. You don't need a lot of them, and as kano said, connections (inbound as well as outbound) to all the major pools is enough.

I have seen latency increase to seconds when there's dozens of hops between IP addresses, which is like "hopping" between bitcoin nodes each having to hit half a dozen more IP addresses to reach the next node.