It appears as though the DNS servers for Comcast have gone down tonight (Sunday). This information has also been reported by MSNBC.com. The internet has been reported to be down for many users in the New England area all the way down to the Washington DC area.
Here is how to temporarily fix your internet:
You must change the DNS server that your computer accesses. This is dependent on how your computer is connected to the internet (Either directly or through a router)
Through a router (i.e Linksys Wireless Router):
1. Access your router settings (for most linksys and netgear routers, go to your address bar and type in 192.168.1.1)
Some other routers use 192.168.1.2 or 192.168.1.12
2. To login to your router, use the router login and password provided
For most linksys and netgear routers, here are settings — Username: admin Password: password
3. Go to the basic settings in your router and change the DNS server settings.
4. Change the DNS server address to Google’s DNS server addresses: address 1: 18.104.22.168 address 2: 22.214.171.124
If you are directly connected to the router (Through an Ethernet cable connected to your modem)
1. Access your DNS settings
2. Change the DNS server address to google’s DNS server addresses: address 1: 126.96.36.199 address 2: 188.8.131.52
You should later change your settings to automatically get the DNS server from your service provider once Comcast fixes the issue.
Here is more information on the Google DNS servers: http://code.google.com/speed/public-dns/docs/using.html