Trouble accessing 'net from any client...(not NAT/VPN!)

[craig.e.shea]

I have been having this problem beginning a little over a year ago, and
I have not been able to find an answer.

Here's my network topology:

Internet-->cable/dsl router-->house network (NT4 server/router)-->my
win2k rras server/router-->hub-->clients

About a year ago, all of a sudden I could no longer reach Passport.net
sites to log in. I can get to msn.com, for example, but I am unable to
login via passport. That means that I am also unable to login to
Hotmail, etc. More recently, I have been unable to reach about 45% of
other websites, both secure and non-secure. I have ruled out the
possibility of spyware/malware and viruses and trojans, and I have SP4
on my Win2K Adv. Server box along with the other latest updates.

At first, I thought this was a problem with my XP Pro client. However,
I also set up a Linux tower and laptop; and when both are connected to
the internet through the hub listed in the topology above, using the
Win2K box as a gateway to the internet, neither Windows clients, nor
Linux clients are able to access Passport sites (I didn't try other
sites such as Discovercard.com). However, when I took my Linux laptop
and connected it to the house network, I was able to login to
Passport.net related sites.

Please do not ask me to check anything with the "house network", as
that is working perfectly (it hasn't been touched in over 5 years as
far as configuration is concerned). It is purely a problem with the
Windows 2000 Advanced Server RRAS router.

Has anyone else ran across this situation and have a solution? I have
reset my RRAS configuration completely (as best as I know how through
the MMC and netsh commands). I am very reluctant to reinstall (might as
well go with Linux at this point... ).

TIA for your help.

 

[Robert L [MS-MVP]]

could be the MTU issue. quoted from http://www.chicagotech.net/troubleshootingie.htm

Can't access some web sitesSymptoms: 1) If you're using MS ICS or Windows server as router to access the Internet, your clients may not be able to access certain web sites. However, the ICS host or the server doesn't have this problem.
2) After installed a new router or cable modem replacing dial-up to access the Internet, you can't access some web sites.
3) You also find that most web sites you can't access are block to ping or they are security sites using HTTPS.

Causes: 1) The problem occurs because many web servers block ICMP messages and the packets are dropped. As a result, the requested web site doesn't load.
2) This problem is caused also by an incompatible MTU networking setting. You may try to install the latest SP. If you use MS ICS, you may want to configure all your Client computers to use the new, lower MTU as the default for all Internet communication. To modify the MTU size, locate the following registry key: HKEY_LOCAL_MACHINE\ SYSTEM\ CurrentControlSet\ Services\ Tcpip\ Parameters\ Interfaces. If you use a router like Cisco DSL Router, you may want to adjusting the PPPoE MTU Size. For example, to adjusting the PPPoE MTU Size on the Cisco DSL Router, do

interface ethernet0
no shut
ip address <ip address> <subnet mask>
ip adjust-mss 1452


Bob Lin, MS-MVP, MCSE & CNE
How to Setup Windows, Network, Remote Access on http://www.HowToNetworking.com
Networking, Internet, Routing, VPN Troubleshooting on http://www.ChicagoTech.net
This posting is provided "AS IS" with no warranties.
I recommend Brinkster for web hosting!

I have been having this problem beginning a little over a year ago, and
I have not been able to find an answer.

Here's my network topology:

Internet-->cable/dsl router-->house network (NT4 server/router)-->my
win2k rras server/router-->hub-->clients

About a year ago, all of a sudden I could no longer reach Passport.net
sites to log in. I can get to msn.com, for example, but I am unable to
login via passport. That means that I am also unable to login to
Hotmail, etc. More recently, I have been unable to reach about 45% of
other websites, both secure and non-secure. I have ruled out the
possibility of spyware/malware and viruses and trojans, and I have SP4
on my Win2K Adv. Server box along with the other latest updates.

At first, I thought this was a problem with my XP Pro client. However,
I also set up a Linux tower and laptop; and when both are connected to
the internet through the hub listed in the topology above, using the
Win2K box as a gateway to the internet, neither Windows clients, nor
Linux clients are able to access Passport sites (I didn't try other
sites such as Discovercard.com). However, when I took my Linux laptop
and connected it to the house network, I was able to login to
Passport.net related sites.

Please do not ask me to check anything with the "house network", as
that is working perfectly (it hasn't been touched in over 5 years as
far as configuration is concerned). It is purely a problem with the
Windows 2000 Advanced Server RRAS router.

Has anyone else ran across this situation and have a solution? I have
reset my RRAS configuration completely (as best as I know how through
the MMC and netsh commands). I am very reluctant to reinstall (might as
well go with Linux at this point... ).

TIA for your help.

 

[fourpastmidnight]

Well, I checked the registry key mentioned regarding the MTU size, but
there were no values under that key. So that means all the default
settings are being used (on both the Win2K server in question, and my
XP client (and most certainly my Linux boxes, as I haven't forayed into
"tweaking" my Linux boxes for maximum performance)).

In any event, I am NOT using ICS (crappy software anyway), and again,
all clients behind the server, Linux and Windows alike, are not able to
access the same sites, however, the server is able to access any site.

Any other suggestions (from anybody)?

Thanks for your reply.