You can kinda slow down a node’s ingress only with an option that is not recommended unless you really need it (storage2.max-concurrent-requests).
See:
Otherwise, the only possible way to restrain network activity of a node is by using external software restricting network flow for instance… which is probably something you shouldn’t do anyway.
What I meant is that if you start a second node too early (I assumed on the same /24 subnet), it will eventually get fully vetted and functional although the first one isn’t full yet.
At this point, both nodes will share ingress, which means that they will both fill up at half speed.
So the first node gets slowed down, even though the total ingress collected by both nodes should globally stay the same (i.e. as if you had only one node).
When the first node gets full, the second node will then receive ingress at full speed.
Side note: Egress isn’t impacted by the number of nodes behind a /24 subnet.