replace the DNS for 4.2.2.2. , works for me.THE COMCAST INTERNET HANG PROBLEM
in Anne Arundel County, Maryland
Problem:
Internet Service apparently hangs. Computer must be restarted. Or IPCONFIG must be used to release then renew the Comcast IP connection.
Cause:
The problem is caused by a combination of poor defaults in Windows XP and an overworked DNS server at Comcast. XP requests DNS service for some valid domain name. The Comcast DNS server at 68.48.0.6 does not respond quickly enough on occasion. Delays of up to 23 seconds have been observed. Your local DNS server may be at a different address, use IPCONFIG /ALL to identify.
XP considers this to be a domain look-up failure and makes a negative cache entry even though the domain look-up request is completely valid. Once the negative entry exists, XP will not look that domain up again until the negative entry times out in 5-20 minutes. The user observes frozen behavior. XP should not have negative DNS caching turned on. This practice began with W2000 and continues unabated out of the sacred halls of Redmond. Comcast should not have a weak DNS server on such an important service offering. The weakness began roughly 6 months ago. You can observe the failure of 68.48.0.6 by snooping your network connection with a product such as ETHEREAL. Ping some valid destination like http://www.cisco.com a few times and observe the DNS failures.
Solution:
Turn off negative DNS caching by making the appropriate registry entry. Any performance hits are minute and only show up as a result of typing incorrect URLs.
Carefully use Regedit to go to: HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ DNScache \ Parameters. Create or edit the following DWORD parameter: MaxNegativeCacheTtl Make the value of this parameter 0 to inhibit negative DNS caching.
Save registry changes by exiting Regedit. Use IPCONFIG /Dnsflush to clear the DNS cache of all entries, good and bad. I also hardwire DNS server 68.48.0.6 to my TCP/IP stack instead of letting DHCP automatically assign it. This circumvents XP's faulty logic in determining that .6 has failed. The downside of the hardwiring is that IF and WHEN Comcast decides to repair .6, I may have to update the hardwiring with the new DNS address.
I also don't bother with the backup Comcast DNS server at 68.48.0.12 since Uncle Bill has decreed that the MS TCP stack does not load balance between two DNS choices but always uses the first until a failure is sensed. Since making these changes, I have experienced NO Internet hangs with Comcast in three weeks. Comcast will not listen to my plea that .6 is faulty and needs attention. It will apparently have to fail completely before they admit that they have a problem.
Oh well, such is life in the big city.
-- jhbenson@comcast.net
The COMCAST HANG Problem
The COMCAST HANG Problem
• Heatware
