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mmoy
 
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Post Posted July 19th, 2007, 5:32 pm

Verizon DSL has a network "outage" problem for the whole state of NH. It's been this way since last Saturday. They told me that they are pulling out boards and putting them back in on a server to see if they can find the problem. Their approach is not surprising given my experiences with their tech support people.

The problem may be a DNS server that is down or very slow.

I was wondering if there is a way to control DNS minimum time to live in the DNS Resolver Cache. It appears that web sites control this setting and that with many sites, the value is very small. Sites where the value is large, typically a day, load much faster as they don't have to go to Verizon's DNS server to get the IP address for the domain name.

Is there a setting in Firefox or Windows to bump up the minimum time to live?
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laszlo

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Post Posted July 19th, 2007, 6:58 pm

The DNS cache settings live in HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/Dnscache/Parameters. The setting I'd try is MaxCacheEntryTtlLimit, though I'm almost certain that this can only shorten TTLs, not extend them.

The respective settings in Firefox are network.dnsCacheEntries with a default of 20 and network.dnsCacheExpiration in seconds with a default of 60.

Or, you could do without the Windows DNS cache and your provider's DNS servers altogether and install Treewalk instead. I'm using it since a few years together with the ICANN slave-root package and never had any DNS problems.
"I'll be dead after I die. I was dead before I was born. Life is a break from death." - Hlynur, 101 Reykjavík

mmoy
 
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Post Posted July 20th, 2007, 5:27 am

Thanks. That's working pretty well. On some sites, performance is as good as it has ever been. On others, it takes a long time to load the first time and then performance is good. I called Verizon this morning and they are still down (or their DNS Server is still down). Keystone Kops if you ask me.

I next need to see if I can get something like this on MacOSX.
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Freee!!

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Post Posted July 20th, 2007, 5:38 am

You could also put some other DNS servers high in your list of DNS servers instead of relying on the one your ISP provides.

mmoy
 
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Post Posted July 20th, 2007, 5:41 am

Could you suggest a few? I checked my router and it doesn't have options for DNS servers (or at least I didn't find the options) so I guess that I'd have to do this per machine.
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old Ol Grumpy
 
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Post Posted July 20th, 2007, 7:22 am

If you have the Verizon supplied software router it should be in the software they provided, MS software more than likely, to change the server numbers. If you got the hardware router they should be able to walk you through changing the setting with the internal switches. Or you may just want to get your own router which allows changing the DNS server number. Watch out for the DNS info you get for routers, sometimes they'll give you router numbers for the U.S. West Coast in error. There seems to be a lack of understanding at times for US Geographical locations. :roll:

mmoy
 
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Post Posted July 20th, 2007, 7:34 am

Ol Grumpy wrote:If you have the Verizon supplied software router it should be in the software they provided, MS software more than likely, to change the server numbers. If you got the hardware router they should be able to walk you through changing the setting with the internal switches. Or you may just want to get your own router which allows changing the DNS server number. Watch out for the DNS info you get for routers, sometimes they'll give you router numbers for the U.S. West Coast in error. There seems to be a lack of understanding at times for US Geographical locations. :roll:


Verizon provides routers? They sent me a modem many years ago when I started service. The replaced the modem with another one a few years later. I've always had to use my own router. I have a Linksys WRT54G and didn't see an option to put in a DNS server address. There was an option to use DDNS but apparently those are paid services.
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mattd7591

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Post Posted July 20th, 2007, 8:42 am

Open DNS
http://www.opendns.com/

You don't have to change the router, just your computer dns servers
--Matt----MSD--

old Ol Grumpy
 
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Post Posted July 20th, 2007, 9:00 am

What Matt said ^
The modem is/was/should have been a modem/router and the software should have come on the disc with the Verizon DSL service when you went on line if it was the "software modem". They supplied two modem/routers here with as many as four or more hookups depending on need. The hardware modem was better than the software one but had the capabilities to change the DNS server numbers. Since you're wireless the changes may all be in the router, I'd check into the Linksys manual. Linksys
http://en.wikipedia.org/wiki/WRT54G
Under Linux we have the ability to change the DNS numbers with a couple of different softwares, depending on hookup method. They pretty much excluded those capabilities for Verizon under Microsoft, making it all automatic, if I remember correctly. If the tech support folks cooperate they should give you different server numbers but most work off scripts and are probably prohibited diversions.

mmoy
 
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Post Posted July 20th, 2007, 9:09 am

They did offer modem/routers a few years after we started our service but they charged an additional amount for them.

It's not fully clear to me at the moment whether the problems are strictly DNS or if they have other problems too. I can't believe that they've let a statewide outage go on for almost a week.

I'll take a look at opendns.
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old Ol Grumpy
 
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Post Posted July 20th, 2007, 9:26 am

There was only the modem/router charge here if you ended the service and didn't return the router in 90 days. It does appear that different parts of the country operate differently due to State Laws where the consumer may be better protected or the State watchdogs more technically literate. Might also relate to the system nomenclature and layout which Verizon took over when they acquired your area network. Like if it was Bell or Bell Atlantic after the breakup of MaBell. If they've been offering the FIOS system in your area and should folks be mostly off of using dial up, and using DSL, it could be they want the DSL folks to move over to FIOS as well in order to simplify systems or it may be the merger of the two different systems is causing an issue.

old FatJohn
 
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Post Posted July 20th, 2007, 9:53 am

Some DNS related problems http://www.dnssec.net/dns-threats

As always, be careful who you trust.

laszlo

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Post Posted July 20th, 2007, 10:38 am

mmoy wrote:Could you suggest a few? I checked my router and it doesn't have options for DNS servers (or at least I didn't find the options) so I guess that I'd have to do this per machine.

When you've already installed Treewalk on one of the machines in your LAN, you can use it as a forwarder for all the others, i.e. you can enter the local IP of the box with Treewalk on it as the first DNS server in the TCP/IP settings of all the others (both Windows and Mac), after checking the predefined "private" and "privlan" acls and the "allow-query" and "allow-recursion" directives in Treewalk's named.conf.

You also don't have to make Treewalk do the entire recursive lookup all the time. You can enter other caching DNS servers you trust in the "forwarders" list and set "forward-first". This way it will only do a complete recursive lookup as a last resort, and you get the best of both worlds.

You can use the two above mentioned methods together to easily play with the DNS settings on one machine and have the others automatically pick up the changes. Treewalk is pretty versatile in this regard; it's actually a full-featured caching DNS server. Here's a link to the Administrator Reference Manual of BIND 9, which Treewalk is based on.

By the way, I know of at least six public Verizon DNS servers, 4.2.2.1 - 4.2.2.6, that are usually pretty quick and reliable. Did you try them all? OpenDNS is okay, too, but I don't quite like what they're doing with failed queries.
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mmoy
 
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Joined: February 17th, 2004, 9:05 pm
Location: New Hampshire

Post Posted July 20th, 2007, 10:47 am

The problem is at home and I'm at the office during the day. I could ask the kids to play around with this but I think that they prefer me to as they could break their machines (or mine).
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