xenserver guest port 80 running apache gives default citrix xenserver page

I have a hp server, running xenserver 7. On xenserver I have a guest, CentOS, which is running apache webserver on port 80. That guest has the static ip 192.168.0.4, xenserver 192.168.0.3. When I visit the CentOS (192.168.0.4) webpage with my web browser, I get the default "Welcome to Citrix XenServer" page instead of my apache website. Sometimes I get the website running on apache after a reboot or reassigning the ethernet port to the centos vm.

The webserver is connected to a switch, which is connected to the same router as the computer I'm visiting the website with.

Could someone tell my why I'm seeing the xenserver page, or how I could find this out?