I've tried this article here titled "How to setup ISA on a cable modem" >> http://www.isaserver.org/pages/tutorials/cable_modem_setup.htm . I applied the regedit as it specified. I've also enabled the DHCP filter and set ICMP Query to allow as well.

I've been restling with this issue for several weeks. This same server worked flawlessly on my dsl connection. Since I've had cable I've formatted and reinstalled Window 2000 Server once and reinstalled ISA server twice. THIS HAS NEVER WORKED WITH MY ADELPHIA CONNECTION.

I going to be studying for the ISA Server Certification (70-227) and I'd like to have this installed. Eventually I'd like to have a Active Directory server setup with a seperate ISA server and a VPN connection.

I'm as frustrated as I can possible be...I really want to get this ISA Server up so that I can move on to the other aspects of my home network.

If I can't get this working I'm going to have bail on ISA server for the time being. Any help would be greatly appreciated.

Many people have been having problems with DHCP and cable modems. Apparently, the way some cable operators implement DHCP doesn't get along with ISA Server. As you noted, you had no problem with your DSL provider.

Don't give up on ISA! You don't need a static IP address to learn most of it. You can still do Web Publishing; you just can't do Server Publishing without changing the IP address in the Server Publishing rule.

Make sure to get yourself a Dynamic DNS service too.

When you run "net stop mspfltex" and then "ipconfig /renew", do you get an IP address?

HTH,
Tom

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http://www.isaserver.org/shinder/



Get It Here!

the 24.29 address is my ISP's DHCP IP.

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5 computer network (4 win9x, 1 win2k), HPNA 1mb network, cable modem.

===================================
don't forget to do security tests
---------------------------------

http://www.vulnerabilities.org/analysis.html
http://www.sdesign.com:8080/cgi-bin/fwtest.cgi
http://scan.sygatetech.com/
http://www.dslreports.com/scan
http://www.dslreports.com/secureme (I love this one)

quote:

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Don't give up on ISA!

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The thing is that my wife is in graduate school and uses the internet for research and as a communication tool for applying for grants and conferences. It is very frustrating for her to have to reboot the server every 3 hours. Not to mention that every couple of days the firewall client gets corrupted when the ISA server loses it's IP address. To fix this I have to uninstall and reinstall the client on each computer. This happens on multiple computers and 2 of them have been recently formatted.

quote:

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When you run "net stop mspfltex" and then "ipconfig /renew", do you get an IP address?

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I've never been able to release and renew the ip address (with the cable modem). I can try doing "net stop smpfltex" and then release and renew when I get home this evening. I'll let you know how that goes

I think I've tried everthing. Is there anythig else I can try that would allow me to keep this server up for more than 3 hours?

Thanks for help.

[This message has been edited by G14 (edited 06 August 2001).]

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5 computer network (4 win9x, 1 win2k), HPNA 1mb network, cable modem.

===================================
don't forget to do security tests
---------------------------------

http://www.vulnerabilities.org/analysis.html
http://www.sdesign.com:8080/cgi-bin/fwtest.cgi
http://scan.sygatetech.com/
http://www.dslreports.com/scan
http://www.dslreports.com/secureme (I love this one)

Okay here's the deal...listen up because this is a good one.

I use the network monitoring tools to find where the fallout was happening. With the ISA Server enabled I was unable to renew my ip address. With it disabled it would renew just fine.

I captured the trace results and e-mailed them to a good friend of mine over at Microsoft. What they discovered is this. In order to renew the IP with ISA Server enable on my cable modem they had to ENABLE NETBIOS on the external NIC!

Here's the interesting part: If I boot up the server with NETBIOS DISABLED I'm unable to renew my IP. Once I enable NETBIOS I'm able to renew the IP. If I then go back and disable NETBIOS again.....it now allows me to renew the IP!

So...enabling NETBIOS does something (i'm not sure what) that allows me to renew my ip address.

My buddy told me that they were looking into this as a possible bug in ISA server. Tom I'll keep you posted if I get any more information.

-Peter

That is interesting! Not a good sign, though. I would hate to have NetBIOS enabled on the external interface of the ISA Server. However, does it work if you create Deny filters for the NetBIOS ports? NetBIOS communication should have nothing to do with DHCP negotiations, so maybe you can enabled NetBIOS but then filter it out.

Thanks!

Tom

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http://www.isaserver.org/shinder/



Get It Here!

quote:

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I would hate to have NetBIOS enabled on the external interface of the ISA Server.

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Port 139 is still closed even though NETBIOS is installed so it doesn't seem to affect the effectiveness of the firewall.

Let's see if I understand. Your ISA server's external interface is connected to the cable modem from which it must obtain a DHCP address. Is that right? If so, what have you done to allow the ISA server to send and receive DHCP information? Isn't there a "DHCP client" filter for this? Did you enable this?

I'm glad I have static addresses because I have frame-relay and not cable, but I suppose that in the ipv6 future, we'll have effective DDNS and everything will be constantly changing and nothing certain.

I have adelphia cable modem for home use. I have no troulbe leasing an IP with ISA running. Netbios is not enabled. Very interesting indeed.

Did you notice that they are blocking port 80? I guess that's one way of enforcing their acceptable use policy!

-Mike