PS2 Network Adaptor Troubles. "DNAS Authenticating"

[Rushy]

Right DNAS error -603 is caused by timing out when trying to connect to Sony's DNAS servers. In other words no connection can be made from you to Sony, thus there it looks like you either have your network config set up incorrectly or something is blocking contact.

Sorry I can't help much more, Sony are very unhelpful ft:

[bowser123]

Assuming I don't have it set up correctly what can I change?
I've only got it working with a manual set up, having to fill in the IP address, subnet, etc that I have got from my Xbox.
Like I said these settings have gave me the green lights on all other areas of the test, surely my connection must be OK to get the green light for connection X2, ping and trace route.

One of the things that has been suggested so far is that it may be a ping related issue. If possible can you take a look at this and see if it may be the cause.

Thanks for the help though so far Rushy, it is appreciated.
And yep, Sony are pretty crap so far at helping.