Weird results - frustrated

[Tim]

Setup is as follows:
ISP is road runner - houston, tx
firewall zonealarm - tested both on enabled and disabled
Cable modem connected to linksys wrt54g wireless rounter
Windows 2003 server connected via lan to wrt54g
Multiple Windows XP clients connected via wireless to wrt54g

On Windows 2003 using IE 6
Slow browsing if any at all at times
can ping FQDN www.google.com sometimes fails sometimes successful
when fails I do nslookup and get response with IP addresses, sometimes
nslookup fails
when fails I ping IP addresses from nslookup with success

On XP machines connected via wireless
completed same procedures as above with same results

I have also tried connecting cable modem directly to computer bypassing
linksys router and same results
Tech support from road runner says no dns issues

What is this then????

P.S. Had very similiar issues about 2 months back, Tech support gave me new
set of DNS servers to try, resolved problem till now
Have tried both using these same DNS servers plus the DNS servers that ISP
DHCP pushes me with same results

 

[Peter Julian]

Setup is as follows:
ISP is road runner - houston, tx
firewall zonealarm - tested both on enabled and disabled
Cable modem connected to linksys wrt54g wireless rounter
Windows 2003 server connected via lan to wrt54g
Multiple Windows XP clients connected via wireless to wrt54g

On Windows 2003 using IE 6
Slow browsing if any at all at times
can ping FQDN www.google.com sometimes fails sometimes successful
when fails I do nslookup and get response with IP addresses, sometimes
nslookup fails
when fails I ping IP addresses from nslookup with success

On XP machines connected via wireless
completed same procedures as above with same results

I have also tried connecting cable modem directly to computer bypassing
linksys router and same results
Tech support from road runner says no dns issues

What is this then????

P.S. Had very similiar issues about 2 months back, Tech support gave me new
set of DNS servers to try, resolved problem till now
Have tried both using these same DNS servers plus the DNS servers that ISP
DHCP pushes me with same results

Your clients should not query your ISP's dns server. Your clients should
only query a private dns server. The private dns zone should not have a root
zone (.) and have its forwarders configured to query ISP on behalf of the
clients for any name resolution in the public namespace.

Otherwise, each clients need to open an extra session with the ISP's dns
through firewall (that dns server can't resolve your private namespace). Bad
for traffic, bad for security, bad for name resolution. Don't configure the
dhcp scope with the ISP's dns as the dns option, only use the private dns
server.

Once you've done that, you have a fighting chance to deal with your internal
packet traffic conditions. Start by analyzing internal traffic, would
subnetting help? Are you using NetBios URLs instead of FQDNs? Whats the
naming hierarchy of the private domain (domain.local)? Is there any virus
activity on the network? Have you considered running a server with Network
Monitor in promiscuous mode? Have you examined your routing tables to
analyze how the default gateways are routing packets within?