BudMan, on 03 October 2012 - 20:42, said:
Well I would for starters do a sniff of the traffic as you get an IP to verify that they are not providing you dns -- this is going to be an option in the dhcp offer.
So for example here on my work box.
dhcpoffer.jpg
Its quite possible that they are in the offer and your router is just not taking them? Never heard of an ISP that does not provide DNS. So if they are not offering it in the dhcp offer - then I would for sure call them on it!
On a client its not that big of a deal you can set to be dhcp but set a static dns, not so sure on router? Could you go into your internet settings and look to see if that is an option. I know I can do it on my pfsense box, but not sure about that cisco - I do believe you can do that on 3rd party firmware. Maybe you might want to go that route? If you verify that they are not handing it out and can not get them too?
edit:
Just fire up wireshark on your client PC you have connected to the modem - then do a ipconfig /release and then renew and you should see your discover go out then the offer then the ack, etc.
You can set DNS servers on the EA4500 router but only in the DHCP options. By the looks of it, the routers interface itself doesn't use the DNS servers you set in the DHCP options but uses the servers provided by the ISP which is sent from the modem to the router.
Which is why when the router comes to check "ciscocloudconnect.com" or whatever site it needs to resolve for this Cisco "cloud" it returns as unavailable and the router is displaying no internet connection. So in a way the router has got an IP etc its got everything but the DNS servers.
So really I have two or possibly three options here
1) Tell my ISP somehow that I am not receiving any DNS servers provided by them
2) Tell Cisco a firmware update is needed so that the router checks by IP and not by resolving a domain name wether there is internet connection, or however they do it on there routers I don't know I can only guess this is what its going
and the 3rd option may well be, because my ISP has full control over this "SuperHub" firmware, it is so locked down you can't change the DNS yourself when you wish to use your own, I reckon that the reason why DNS servers are not been provided in Modem mode is because the DNS servers are in fact hard coded into the firmware of the SuperHub itself. (Virgin Media can send firmware updates out to the SuperHub whenever they want and it will automatically update once plugged in).
But really the root cause of this issue is not the router, not ciscos fault but in fact Virgin Media.
I can try the Wireshark thing but what difference is it going to make, if connecting directly to the SuperHub in Modem mode is not working, then something is clearly wrong, I can see that there are no DNS servers being set. I have never seen this happen ever and I can't come to terms with what has happened here.
I am going to try my best to tell Virgin Media what is happening here and let you know what the outcome is or If I need any additional help ill post in this thread but thanks for helping me, this has really made my mind explode today working this out.
Matt.