personal-website/content/blog/2021/issues-with-docker-swarm-on-esxi.md

---
title: "Issues with Docker Swarm on ESXi"
description: "How to make Docker Swarm work with Nodes on ESXi"
publishdate: "2021-04-20"
author: "Laura 🌹"
---

I once tried to set up a Docker Swarm Cluster. I had three nodes, two on Proxmox hosts, and one on a ESXi 7 host. The nodes had a GlusterFS storage attached to them which synced data to all three nodes so containers could be started on any node.

Everything worked wonderfully. Until I found out that some Containers couldn't talk to others.

Off to troubleshooting then. It seemed very sporadic, with communication working most of the time somehow. I tried some things, until I found out that it only happens if a container on the ESXi node tried to talk to others on the Proxmox nodes.

After _A LOT_ of googling and searching many a reddit thread I finally found out why:  
It seems like ESXi, even when in standalone mode, silently drops packets on `udp/4789`, which apparently is VMWares `VTEP VXLAN Port for NSX-T`.

The fix for the Swarm cluster is to (re-)create the Swarm Cluster with `--data-path-port=xxxx`:
```
docker swarm init --data-path-port=(port that's not 4789)
```

Afterwards all communication works again 🎉
small redesign =) 2023-09-01 11:02:21 +02:00			`---`
			`title: "Issues with Docker Swarm on ESXi"`
			`description: "How to make Docker Swarm work with Nodes on ESXi"`
			`publishdate: "2021-04-20"`
add reading time and update stuff 2023-09-03 20:29:35 +02:00			`author: "Laura 🌹"`
small redesign =) 2023-09-01 11:02:21 +02:00			`---`

add reading time and update stuff 2023-09-03 20:29:35 +02:00			`I once tried to set up a Docker Swarm Cluster. I had three nodes, two on Proxmox hosts, and one on a ESXi 7 host. The nodes had a GlusterFS storage attached to them which synced data to all three nodes so containers could be started on any node.`
small redesign =) 2023-09-01 11:02:21 +02:00
			`Everything worked wonderfully. Until I found out that some Containers couldn't talk to others.`

			`Off to troubleshooting then. It seemed very sporadic, with communication working most of the time somehow. I tried some things, until I found out that it only happens if a container on the ESXi node tried to talk to others on the Proxmox nodes.`

			`After _A LOT_ of googling and searching many a reddit thread I finally found out why:`
			It seems like ESXi, even when in standalone mode, silently drops packets on `udp/4789`, which apparently is VMWares `VTEP VXLAN Port for NSX-T`.

			The fix for the Swarm cluster is to (re-)create the Swarm Cluster with `--data-path-port=xxxx`:
			```
			`docker swarm init --data-path-port=(port that's not 4789)`
			```

			`Afterwards all communication works again 🎉`