Why is Web Browsers so slow at Resolving Hosts

[jim tate]

Tom Needs a Hat Mitchell wrote:

>On Wed, Mar 03, 2004 at 12:45:19AM -0500, jim tate wrote:
>  
>
>>Tom Needs a Hat Mitchell wrote:
>>    
>>
>>>On Tue, Mar 02, 2004 at 05:02:51PM -0500, jim tate wrote:
>>>
>>>
>>>      
>>>
>>>>Fedora2-test1
>>>>Mozilla,Firefox,Konqueror all three are very slow at Resolving Hosts and 
>>>>connecting
>>>>to Websites.
>>>>Resolv.conf is setup with "nameserver 192.168.1.1" gateway, 
>>>>Linksys-WRT55AG,
>>>>eathernet, does not make any difference as to what  make of eathernet 
>>>>card your using,
>>>>not using wireless.
>>>>Another PC and Laptop using Fedora1 core has no problems of resolving 
>>>>,fast, on > same network.
>>>>        
>>>>
>....
>
>  
>
>>>On the two linux boxes compare the results of "chkconfig --list | sort "
>>>Also on both machines compare:
>>>     /etc/resolv.conf          resolver configuration file
>>>     /etc/host.conf            resolver configuration file
>>>     /etc/hosts
>>>
>>>My guess is that the quick machines are getting name/host resolution from
>>>the comcast name servers and not the Linksys.  Check also the name server
>>>configured inside the Linksys, if it is wrong it will be slow.
>>>
>>>My strategy would be to setup a caching name server and list the comcast
>>>name servers and bypass the Linksys.
>>>
>>>You can snoop on the wire and watch host host names are resolved 
>>>(tethereal)
>>>and compare the quick and the slow boxes.
>>>      
>>>
>
>  
>
>>You were right after running "tethereal" and going to http://linuxtoday.com, you can see where
>>the Fedora1 core box (192.168.1.2) was going to Comcast.net dns numbers (63.236.73.20)and
>>The Fedora2-test1 box(192.168.1.3) is going to the (192.168.1.1)Gateway, Linksys router and
>>through the router is where the resolving delay is.
>>    
>>
>
>Remember that boxes like the Linksys switch packets.  You need to snoop (tehereal)
>on each box.  i.e. 192.168.1.2 cannot snoop 192.168.1.1 traffic unless you use
>an old style non switching hub.
>
>  
>
>>How do I correct this on the Fedora2-test1 box.
>>    
>>
>
>Are you using DHCP on one or both boxes?
>
>What does comparing resolv.conf and host.conf tell you?
>
>Try adding the Comcast.net DNS resources to /etc/resolv.conf on the slow box.
>You can leave the Linksys ipaddress commented out or last in the list.
>
>Based on mail headers, in your case these may be useful in your hosts
>and resolv.conf files.
>   68.87.96.3 dns01.jdc01.pa.comcast.net.
>   68.87.96.4 dns02.jdc01.pa.comcast.net.
>
>Remember that one works and the other does not.  The answer is at hand.
>
>
>  
>
Linksys is connected to to the cable modem by DHCP, I don't have a fixed IP
asigned by Comcast.net is DHCP.
The network side of Linksys is 192.168.1.1 (Gateway)and each of the two 
PC and Laptop have
their own IP numbers.  all three are connected to Linksys by ethernet 
cables.
This only started after I converted this P3/ 800 box to Fedora2-test, 
with Fedora 1
is was okay.
The resolv.conf, host.conf, and hosts files have the same settings on 
all three boxes

Doing /sbin/chkconfig --list | sort , all services are the same with the 
exception that
Fedora2-test has four extra services than does Fedora1.

Readahead  0:off  1:off  2:off  3:off 4:off  5:on  6:off
cpuspeed     0:off  1:on   2:on   3:on  4:on   5:on  6:off
firstboot      0:off  1:off  2:off  3:on  4:off  5:on  6:off
ypbind         0:off  1:off  2:off  3:off 4:off  5:off 6:off  (no nis 
server is installed).


Thanks
Jim Tate