Re: Many Web Pages are not opening - Please helpand advice

  • From: "Thomas W Shinder" <tshinder@xxxxxxxxxxx>
  • To: "[ISAserver.org Discussion List]" <isalist@xxxxxxxxxxxxx>
  • Date: Thu, 29 Apr 2004 07:22:03 -0500

Hi Nabil,
 
The Web Proxy and Firewall clients use the DNS cache in their respective
services by default.
 
SecureNAT clients resolve the names themselves.
 
Are you sure this is a DNS problem? Another issue is that I believe that
yahoo.com has so many entries, that you must allow for TCP queries,
since there are too many entries to fit into a single UDP message.
 
HTH,
Tom
 
 
Thomas W Shinder
www.isaserver.org/shinder <http://www.isaserver.org/shinder> 
ISA 2004 Beta - Get it now!
http://www.microsoft.com/isaserver/beta/default.asp
<http://www.microsoft.com/isaserver/beta/default.asp> 
ISA Server and Beyond: http://tinyurl.com/1jq1
Configuring ISA Server: http://tinyurl.com/1llp
<http://tinyurl.com/1llp> 

 

        -----Original Message-----
        From: Nabil, Ahmed [mailto:anmahmou@xxxxxxxxxx] 
        Sent: Thursday, April 29, 2004 7:11 AM
        To: [ISAserver.org Discussion List]
        Subject: [isalist] Re: Many Web Pages are not opening - Please
helpand advice
        
        
        http://www.ISAserver.org
        
        
        Tom,
        
        Sorry for the many questions but i am confused now. Could you
please briefly explain what is the use of this Keys. As far as i
understand there is a local name cache for  names that have been
resolved via queries to DNS servers.  Since it resides in memory, this
is the first choice for resolution of fully qualified domain names, or
FQDN.  Resolved names are kept until the respective TTL expires which is
6 hours then they are deleted.
        
        This means that any name resolved by the WEB proxy service will
remain in the ISA DNS proxy cache for six hours except if the client
have an IP for a DNS then it will use it first.
        
        Now in my case why was this giving me a problem. For example
yahoo .com was resolved and the resolving is cached and then you try to
open before the six hours and it didn't open, nothing is changed I guess
!!!!!!! Thats confusing.
        
        Please advice.
        
        Thanks in advance.
        
        Ahmed
        
        -----Original Message-----
        From: Thomas W Shinder [mailto:tshinder@xxxxxxxxxxx
<mailto:tshinder@xxxxxxxxxxx> ]
        Sent: Thursday, April 29, 2004 1:19 PM
        To: [ISAserver.org Discussion List]
        Subject: [isalist] Re: Many Web Pages are not opening - Please
helpand advice
        
        
        http://www.ISAserver.org <http://www.ISAserver.org> 
        
        Hi Ahmed,
        
        Cause that is how ISA works. You can edit the Registry to change
the
        default behavior.
        
        HTH,
        Tom
        
        Thomas W Shinder
        www.isaserver.org/shinder
        ISA 2004 Beta - Get it now!
        http://www.microsoft.com/isaserver/beta/default.asp
<http://www.microsoft.com/isaserver/beta/default.asp> 
        ISA Server and Beyond: http://tinyurl.com/1jq1
<http://tinyurl.com/1jq1> 
        Configuring ISA Server: http://tinyurl.com/1llp
<http://tinyurl.com/1llp> 
        
        
        
        
        -----Original Message-----
        From: Nabil, Ahmed [mailto:anmahmou@xxxxxxxxxx
<mailto:anmahmou@xxxxxxxxxx> ]
        Sent: Thursday, April 29, 2004 5:52 AM
        To: [ISAserver.org Discussion List]
        Subject: [isalist] Re: Many Web Pages are not opening - Please
helpand
        advice
        
        
        http://www.ISAserver.org <http://www.ISAserver.org> 
        
        But why is it ignoring the TTL or not obeying it ??
        
        Thanks and have a nice day,
        
        Ahmed Nabil
        
        -----Original Message-----
        From: Jim Harrison [mailto:jim@xxxxxxxxxxxx
<mailto:jim@xxxxxxxxxxxx> ]
        Sent: Tuesday, April 27, 2004 3:03 PM
        To: [ISAserver.org Discussion List]
        Subject: [isalist] Re: Many Web Pages are not opening - Please
helpand
        advice
        
        
        http://www.ISAserver.org <http://www.ISAserver.org> 
        
        The default isn't zero.
        This is ISA's "local" name resolution cache.
        The problem is that it doesn't obey record TTL.
        
          Jim Harrison
          MCP(NT4, W2K), A+, Network+, PCG
          http://isaserver.org/Jim_Harrison/
<http://isaserver.org/Jim_Harrison/> 
          http://isatools.org <http://isatools.org> 
          Read the help / books / articles!
        
        
        On Tue, 27 Apr 2004 11:42:44 +0200
         "Nabil, Ahmed" <anmahmou@xxxxxxxxxx> wrote:
        http://www.ISAserver.org <http://www.ISAserver.org> 
        
        Jim,
        
        It seems to be working fine now. I don't yet understand why was
this
        setting making this problem. Is the default setting while
installing ISA
        in this registry key is Zero, if so then how it became this
large number
        ??
        
        Your comments is highly appreciated.
        
        Thanks and have a nice day,
        
        Ahmed
        
        -----Original Message-----
        From: Jim Harrison [mailto:jim@xxxxxxxxxxxx
<mailto:jim@xxxxxxxxxxxx> ]
        Sent: Thursday, April 22, 2004 3:38 PM
        To: [ISAserver.org Discussion List]
        Subject: [isalist] Re: Many Web Pages are not opening - Please
helpand
        advice
        
        
        http://www.ISAserver.org <http://www.ISAserver.org> 
        
        You might want to try reducing or eliminating your ISA DNS
cache.
        This article discusses how to do that:
        
http://www.isaserver.org/tutorials/ISA_Clients__Part_1__General_ISA_Serv
<http://www.isaserver.org/tutorials/ISA_Clients__Part_1__General_ISA_Ser
v> 
        er_Configuration.html
        
          Jim Harrison
          MCP(NT4, W2K), A+, Network+, PCG
          http://isaserver.org/Jim_Harrison/
<http://isaserver.org/Jim_Harrison/> 
          http://isatools.org <http://isatools.org> 
          Read the help / books / articles!
        
        
        On Thu, 22 Apr 2004 08:54:46 +0200
         "Nabil, Ahmed" <anmahmou@xxxxxxxxxx> wrote:
        http://www.ISAserver.org <http://www.ISAserver.org> 
        
        
        Good morning All,
        
        I re-checked my DNS forwaders on my DNS Server and they are
correct
        (pointing to our ISP), I believe the problem is the internet DNS
        resolution through ISA. Please advice. this is very irritating
problem.
        Sometimes I can't open any sub pages from yahoo, Microsoft & NAI
and
        then after a couple of hours they are opened fine and another
set of
        pages is down.
        
        This morning I tried to open a normal page and here is what I
get.
        
        
        The Web site cannot be found
        The Web site you are looking for is unavailable due to its
        identification configuration settings.
        
        
------------------------------------------------------------------------
        --------
        
        Please try the following:
        
        Click the Refresh button, or try again later.
        
        If you typed the page address in the Address bar, make sure that
it is
        spelled correctly.
        
        Click the Back button to try another link.
        11001 - Host not found
        Internet Security and Acceleration Server
        
        
------------------------------------------------------------------------
        --------
        
        Technical Information (for support personnel)
        
        Background:
        This error indicates that the gateway could not find the IP
address of
        the Web site you are trying to access.
        
        
        
        
        I checked the Web Proxy log for my request and attached below
the line
        extracted from the log.
        
        10.202.80.108, anonymous, Mozilla/4.0 (compatible; MSIE 6.0;
Windows NT
        5.0; .NET CLR 1.1.4322), -, 4/21/2004, 8:21:25, -, ISA Server
name, -,
        www.socks.permeo.com, -, 80, 0, 301, 0, http, -, GET,
        http://www.socks.permeo.com/AboutSOCKS/SOCKSOverview.asp
<http://www.socks.permeo.com/AboutSOCKS/SOCKSOverview.asp> , -, Inet,
        11004, -, -, -
        
        When i clear the cache and restart the server, every thing works
fine
        for sometime.
        
        Please advice and help.
        
        Thanks and have a nice day,
        
        Ahmed
        
        
        
        
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