mersenneforum.org  

Go Back   mersenneforum.org > Great Internet Mersenne Prime Search > PrimeNet

Reply
 
Thread Tools
Old 2003-04-10, 22:23   #1
Prime95
P90 years forever!
 
Prime95's Avatar
 
Aug 2002
Yeehaw, FL

5·7·11·19 Posts
Default DNS questions

My ISP has two DNS servers. 24.95.227.34 and 24.95.227.35.

Q1) Why has the new mersenne.org IP address propagated to the second server but not the first?

Q2) I placed the second server first in my Windows XP list of DNS servers. All works OK. Except --- once a day Windows XP reverts back to thinking mersenne.org is at 216.120.70.80. I have to switch the DNS server list and switch it back to restore the correct IP address for mersenne.org. Why is WindowsXP doing this to me?
Prime95 is offline   Reply With Quote
Old 2003-04-10, 22:43   #2
cperciva
 
Oct 2002

43 Posts
Default Re: DNS questions

Quote:
Originally Posted by Prime95
Q1) Why has the new mersenne.org IP address propagated to the second server but not the first?
Probably the first server cached the old address more recently. DNS updates don't propagate, old values die out.

Quote:
Q2) I placed the second server first in my Windows XP list of DNS servers. All works OK. Except --- once a day Windows XP reverts back to thinking mersenne.org is at 216.120.70.80. Why is WindowsXP doing this to me?
Probably the first server failed to respond to a request once, so Windows decided to switch to using the second server as primary. Which makes sense, since otherwise if the first server died, every request you ever did would have to wait for a timeout before it would be sent to the second server.
cperciva is offline   Reply With Quote
Old 2003-04-12, 01:54   #3
trif
 
trif's Avatar
 
Aug 2002

2×101 Posts
Default

For some strange reason, the first DNS server is holding on to the old DNS information. It has a TTL of 24 hours, so it should have been cleared out long ago. All of the .org servers have the updated DNS, so the only thing I can think of is that the first DNS server is having problems querying the .org servers and is renewing the TTL on the old info. I can see that at this moment, the "bad" server is showing a TTL of just under 24 hours, so presumably it very recently queried the old nameservers for mersenne.org, when it should have queried the .org servers, gotten the new nameservers, and then queried them for the proper IP.

You can just use the "good" DNS server and eliminate the other until it gets itself fixed.
trif is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Two questions: Dubslow GPU Computing 1 2011-08-05 18:22
Questions about the QS Carmichael Factoring 8 2007-04-10 11:30
Questions OmbooHankvald Prime Sierpinski Project 2 2005-08-01 20:18
LLR questions OmbooHankvald Math 6 2005-06-23 11:42
A few questions :) xtreme2k Lounge 59 2002-10-31 06:20

All times are UTC. The time now is 13:10.

Tue Jan 26 13:10:43 UTC 2021 up 54 days, 9:22, 0 users, load averages: 2.54, 2.77, 2.77

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.