Ingress Network limited to 128 ports?

It seems that there is a limitation either with the ingress network, or the docker_gwbridge network, as its seemingly impossible to expose more than 128 ports externally via ingress on a swarm cluster. It does not matter how many nodes comprise the cluster; this issue occurs on a single node swarm cluster or multi-node.

To see this for yourself, on a empty swarm cluster, simply run:
docker service create -p 80 nginx
129 times..

128 of them will succeed to provision and expose their ports 30000 - 30128, however on reaching the 129th, the task will set pending forever. If i kill one of the previously deployed services, the one that is pending will instantly deploy.

Note that whilst this limitation exists for the ingress network, it does NOT apply to the standard bridge network. On the same cluster, i was able to deploy 300 containers, each exposing a port via the default bridge network.

Is there system tuning that is required to exceed 128 concurrently exposed ingress ports?

Reproduce the limit on an empty swarm cluster with repeated docker service create -p 80 nginx commands, then trace ingress network and docker_gwbridge port allocation through swarmkit's task scheduling path. Compare the behavior with services using the standard bridge network; done means identifying why the 129th ingress task remains pending and documenting or fixing the limit.