>Hello Creighton,
>
> Wednesday, February 19, 2003, 3:41:24 AM CET, you wrote:
>
> cs>         Next, I have a small setup, only one server and one node
> so far, cs> however this is a proof-of-concept attempt for my local
> office.  The cs> powers that be are afraid to abandon M$ on the
> workstaions so I have been cs> trying to setup this k12ltsp (RedHat
> 7.3) server as an internet gateway cs> for the windoze machines.  My
> test machine is a win95 that reads the net cs> card, asks for and
> gets a number from the dhcpd, but cannot read the cs> 'network
> neiborhood' nor can I login to the server by telnet.  This same cs>
> machine boots with an etherboot boot disk fine.
>
> The fact that it cannot read the network neighbourhood can be due to
> your not having configured samba properly. No matter sofar.
> If you cannot telnet to it, that could be caused by security
> settings; I know that Debian 3.0 usually doesn't activate telnet but
> only the encrypted version, ssh.
> Can you ping the linux box? (Does the IP-address given by win95:
> winipcfg) for the dhcp server match what you configured?

For SAMBA, it is important to set the WORKGROUP = WHATEVER directive
in the smb.conf file, where WHATEVER is the workgroup the rest of your
win9x/nt office is on (Right-click Network Neighborhood, properties,
Identification). Also make sure they are on the same subnet.

> On the linux box, you need masquerading and a GOOD firewall for what
> you plan, for a start these rules should suffice (FOR A START!!!)
>
> echo "1" >/proc/sys/net/ipv4/ip_forward       to turn on forwarding
> iptables -t nat -A FORWARD -i eth0 -o ppp0 -j MASQUERADE
> iptables -A INPUT -i ppp0 -p tcp -m tcp --tcp-flags SYN,RST,ACK SYN
> -j DROP
>
> (from memory, countercheck with iptables man-page)

Here is my iptables setup (RH 7.2) on a stand alone machine between
the Internet and my LAN. I keep it in /etc/rc.d/rc.firewall which I
then run in /etc/rc.d/rc.local so it will be run if the server should
reboot:

-----
echo Setting up IP Forwarding ...
iptables -F; iptables -t nat -F; iptables -t mangle -F
iptables -t nat -A POSTROUTING -o eth1 -j SNAT --to 123.456.789.012
# Turn off pop3 from Internet
iptables -A INPUT -p tcp --destination-port 110 -i eth1 -j DROP
# Turn off MySQL from Internet
iptables -A INPUT -p tcp --destination-port 3306 -i eth1 -j DROP
# Turn off Time from Internet
iptables -A INPUT -p tcp --destination-port 37 -i eth1 -j DROP
echo Turning on IP Forwarding ...
echo 1 > /proc/sys/net/ipv4/ip_forward
-----

eth0 is my lan, and eth1 is my dsl connection.
123.456.789.012 is my static internet IP address.
I turn off ports that I don't want the Internet to have access to.

Although this is not a true firewall, it has worked well for me for
about 2 years. I think I got most of the configuration information
from this web page, but I'm not sure:
http://tldp.org/LDP/nag2/x-087-2-masq.configuration.html

> This is not a tight firewall, but just a quickstart, assuming you
> connect to the internet via ppp0 interface and localnet is eth0.
> At least better than nothing, no idea, what redhat has for default.
> In general, the recommendation to have a second PC as
> internet-gateway/firewall is pretty reasonable for me, but it is not
> always possible to spare a machine for that.
> You could look out, e.g. at etherboot.org Links or so I saw a
> netbootable firewall-Linux (a machine gets Linux from the net,
> readonly, and from then on is a firewall: Even if cracked, no data
> can be destroyed on that particular PC...)
>
> cs> Can someone point me in the direction of some docs that might
> give me some cs> direction, please?
>
> For this network/internet-relay stuff, you could look for a FAQ on
> www.tldp.org (The Linux Documentation Project), I seem to remember
> there was one with MASQUERADING in its name, in the networking
> section.
>
> cs> Also, is there anyone here who has a ltsp setup
> cs> running well in the Greater Cincinnati area, such as a school?
>
> Sorry, Greater Cologne area better fits the place I'm working at :-)
>
> Best regards,
>  Anselm
> mailto:[EMAIL PROTECTED]

I'm not so good at the ltsp stuff yet, but if you need help with
iptables and samba I may be able to assist.

Sincerely,
Ben Rousch






-------------------------------------------------------
This SF.net email is sponsored by: SlickEdit Inc. Develop an edge.
The most comprehensive and flexible code editor you can use.
Code faster. C/C++, C#, Java, HTML, XML, many more. FREE 30-Day Trial.
www.slickedit.com/sourceforge
_____________________________________________________________________
Ltsp-discuss mailing list.   To un-subscribe, or change prefs, goto:
      https://lists.sourceforge.net/lists/listinfo/ltsp-discuss
For additional LTSP help,   try #ltsp channel on irc.freenode.net

Reply via email to