I had recently updated my website's first page (index.html), the website
is hosted on my ISP's datacentre. now the problem I am facing is if I
type my address from my LAN (www.xyz.com) it shows me the old page, but
if I type as www.xyz.com/index.html I am able to see the new page.

From outside the proxy I can see the updated page. I think the cache in
my proxy is not getting updated, how to do?