From 53e6ae68c9ff8ea9904984dd067df1b6a6af1ce9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20H=C3=B6rtnagl?=
 <christian.hoertnagl@univie.ac.at>
Date: Fri, 24 Apr 2020 07:36:11 +0200
Subject: [PATCH] documentation (firewall)

---
 prom.md | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/prom.md b/prom.md
index 47ae230..37a2f50 100644
--- a/prom.md
+++ b/prom.md
@@ -25,6 +25,11 @@ of `multiparty-meeting` but connected as an interactive client.
 | `PROM_PORT` | if set, enable exporter on this port |
 | `PROM_QUIET` | if set, include fewer labels |
 
+If `multiparty-meeting` was installed with 
+[`mm-absible`](https://github.com/misi/mm-ansible)
+it may be necessary to open the `iptables` firewall that was established
+with `ferm` for incoming TCP traffic on `PROM_PORT`.
+
 ## License
 
 MIT License (without copyright notice)