Today i got task to onboard one server exposed to internet. It is Linux server, use RHEL. From architecture design the best practice workflow as shown below whenever we would establish something to outside world.

Internet -> load balancer -> reverse proxy -> web server -> app server -> db server

Everything is well configured from network side, including NAT and created virtual ip pool from load balancer side. Same goes for backend servers.

So, i tried to configure reverse proxy with very simple two lines;

ProxyPass / http://[ip local web server]:80
ProxyPassReverse / http://[ip local web server]:80

Start the HTTPD service and test from public ip. It giving DNS Lookup Failure somehow. It always been working before but not today. Very weird.

Just took couple minutes and realize i did very simple mistake, TYPO.

There is minus slash symbol on the ProxyPass configuration! It supposed to be like below.

ProxyPass / http://[ip local web server]:80/
ProxyPassReverse / http://[ip local web server]:80/

Did you see it? did you realize?

Yeah something must be fixed even using single character.

Works like charm now.

Don’t forget to restart the HTTPD service to apply the changes.