Zimbra Firewall Configuration with ufw for Ubuntu

Installing UFW on UbuntuInstall the UFW on Ubuntu by executing the command as :

sudo apt-get update && sudo apt-get -y install ufw

Configure Zimbra Firewall usign UFWBecause of recent Memcache amplification attacks for UDP ports, we won’t enable udp port as it will cause serious problems. Due to this reason we will use only tcp ports which is protected from these.

We need an application profile for UFW, so let’s create this profile as:

sudo nano /etc/ufw/application.d/zimbra

Then add the following lines

[Zimbra]
title=Zimbra Collaboration Server
description=Open source server for email, contacts, calendar, and more.
ports=22,25,80,110,143,161,389,443,465,514,587,993,995,7071,8443,11211/tcp

After that enable app profile on ufw

sudo ufw allow Zimbra
sudo ufw enable

Then add ssh port as

sudo ufw allow ssh

To make any changes to the Zimbra profile, update it using:

$ sudo ufw app update Zimbra
Rules updated for profile 'Zimbra'
Skipped reloading firewall

Because for a single server installation, Memcache is not used outside the local server, consider binding it to the loopback ip address. So, use the commands:

sudo su - zimbra
zmprov ms zmhostname zimbraMemcachedBindAddress 127.0.0.1
zmprov ms zmhostname zimbraMemcachedClientServerList 127.0.0.1

Then restart Memcache services.

sudo su - zimbra -c "zmmemcachedctl restart"

Restricting Access to Admin dashboardAs it is a good practice to always restrict access to port 7071 to a trusted network or IP, so do it by typing:

$ sudo ufw allow from 192.168.1.10 to any port 7071
$ sudo ufw allow from 192.168.1.0/24 to any port 7071

So, this is how you can configure your Zimbra Server with firewall using ufw on Ubuntu 18.04 LTS.