Ok before we all break out into a this mtu and that mtu and yadda yadda. All I want to know is what mtu your pppoe connection has as set by iburst, thanks 
Mine is showing as 1432.
The reason for this post is due forwarding from my linux server and the following:
http://redvip.homelinux.net/varios/2.4routing/x1807.html
http://redvip.homelinux.net/varios/2.4routing/x1834.html
http://www.e-infomax.com/ipmasq/howto/c-html/mtu-issues.html
Mine is showing as 1432.
The reason for this post is due forwarding from my linux server and the following:
http://redvip.homelinux.net/varios/2.4routing/x1807.html
http://redvip.homelinux.net/varios/2.4routing/x1834.html
http://www.e-infomax.com/ipmasq/howto/c-html/mtu-issues.html