Recently i installed varnish into our cPanel server on my web hosting company in Malaysia. The installation is pretty straight forward and simple but the only issue here is that my main website is getting an 'error' text rather than showing me my varnish website. If you inspect element, it will gives you Error 418 in its http headache with the error "I'm a teapot" which makes me a little irritated with it.
I was getting this error because my main website has a dedicated ip which is different from the rest of the account. This also means that my varnish configuration is a little different from all other account in it. But getting 'error' isn't what i was after. Normally one will just skip varnish entirely because it doesn't work. However, you shouldn't be worry too much on it. Apparently the error was caused by varnish cached and if you plunge it, your website should be showing up fine. Below you can find purge command for varnish 3.0
sudo varnishadm "ban req.http.host ~ www.mydomain.com"
or
sudo varnishadm "ban req.http.host ~ /"
The only thing you might need to take note is the browser cache showing on your browser which might mislead you and makes you panic for a bit. If it still showing error 418, all you need to do is wait a little bit and it should show up nicely.