Knowledge Base

Nginx shows warning when running nginx -t: nginx: [warn] protocol options redefined for 203.0.113.2

The following warning shows up when running nginx -t via CLI:

# nginx -t
nginx: [warn] protocol options redefined for 203.0.113.2:443 in /etc/nginx/plesk.conf.d/vhosts/example.com.conf:7
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful
Server preference http2 is enabled:

# plesk bin http2_pref --status
Enabled
Preferred domain is set to example.com in Domains > example.com > Hosting & DNS > Hosting
Running command plesk bin http2_pref --enable may fix the warning temporarily, but will show up again.

Product issue:

PPPM-14042 "Enabling HTTP/2 no longer results in the 'protocol options redefined' warning."
Fixed in:
- Plesk Obsidian 18.0.54 18 July 2023 (Linux)

Please consider updating your server:

If update is not possible for some reason you may try the following

Use Event Handlers to update nginx configuration files:

Connect to the server via SSH
Create and Edit file /root/update_nginx.sh that will be used by the Event Handler:

#!/bin/bash
vhostDir=$(grep VHOST /etc/psa/psa.conf | awk {'print $2'})
if [ ! -z "$vhostDir" ] ; then
sleep 15
find $vhostDir/system/*/conf -type f -name "nginx.conf" | xargs -i sed -i '/http2/!s/(listen [0-9.]*:443 ssl)/1 http2/' {}
find /etc/nginx/plesk.conf.d/webmails/ -type f -name "*.conf" | xargs -i sed -i '/http2/!s/(listen [0-9.]*:443 ssl)/1 http2/' {}
find /etc/nginx -type f -name "*.conf" | xargs -i sed -i '/http2/!s/(listen [0-9.]*:443 ssl)/1 http2/' {}
else
echo "Vhost DIR fetch failed. Exiting ..." && exit 0
fi
Set executable permissions to the script:

# chmod +x /root/update_nginx.sh
Log into Plesk
Create Event Handler by going to Tools & Settings > Event Manager > Add Event Handler and add the following details:
- Event: Physical hosting created
- Priority: 50
- User: root
- Command: /root/update_nginx.sh
Repeat step 5 for Event: Physical hosting updated