I agree with Ken, the setup does sound confusing. Before modifying your 
firewall scripts, are you sure that you need a firewall at all? I would 
guess that if your server and terminals are all on a private network 
(10.0.0.0) then you probably gain access to the internet (or other 
network) via some other router - which probably has it's own firewall. Is 
your intention to use the LTSP server to act as a gateway/firewall as 
well? If so, I'm not sure I would run both things on the same server. I'd 
probably set up a separate box to act as a gateway/firewall to the 
internet (there are many great and cheap ways to accomplish this).
Cheers

>>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<<

On 11/27/01, 9:57:03 AM, "Ken Godee" <[EMAIL PROTECTED]> wrote 
regarding Re: [Ltsp-discuss] Blocked by firewall:


> Your set up seems confusing.....
> A firewall is usally set up to block external untrusted networks, ie.
> the internet. Which would appear to be on your eth0. Then
> normally you would have a second nic installed for trusted/internal
> networks on ie. eth1 and your server would be the gateway/firewall.
> Right now your firewall is doing its job correctly, it's
> blocking/dropping what appears to be a 'spoofed' address.
> It thinks its a spoofed address because the address of 10.0.0.50
> is a non-routable address that is not orginating from your machine
> or internal net. This is how spoofing is done. sending packets to
> someones machine trying to fake that it orginally came from
> them in the first place.
> I'm not sure what you can do to make this work like you want
> except to punch holes in your firewall (bad idea).
> You should be able to find a file in your /etc or /etc/rc.d or where
> ever named "rc.firewall" or something like that. This will be a script
> that is run at boot up that loads the firewall rules for iptables.
> Once you find it you should be able to find a section that is
> headed with something like #SPOOFING etc with a few iptables
> rules that block spoofing attacks, comment them out to set off
> protection for spoofing. Most rc.firewall scripts contain a default
> set of ip spoofing rules.
> I would expect you'll run into more problems thou, you'll probally
> have to punch several more holes in your firewall to get it to
> work like your trying to get it to.
> I'm not an expert by any means on this. Most firewalls start with
> deny all except what is explicitly permitted.
> With all that said maybe you could add a couple of iptables rule
> to just allow 10.0.0.50 only?
> My choice would be to serve ltsp on trusted networks only.

> Also the only searchable email archive for ltsp I know of.....
> http://www.mail-archive.com/[email protected]/







> > Hello,
> >
> > I am trying to setup an X-terminal connected to a SuSE linux 7.1
> > server.  On the server I have a firewall set up using SuSEfirewall2
> > which, to the best of my knowledge, is just a front end for iptables.
> > If I turn the firewall off then the terminal boots up with no
> > problems.  However, with the firewall on it stops and the following
> > appears in the /var/log/messages file on the server:
> >
> > Nov 25 17:50:54 kipling dhcpd: DHCPDISCOVER from 00:20:af:20:f7:4f via
> > eth0 Nov 25 17:50:54 kipling dhcpd: DHCPOFFER on 10.0.0.50 to
> > 00:20:af:20:f7:4f via eth0 Nov 25 17:50:54 kipling kernel:
> > SuSE-FW-DROP-ANTI-SPOOFINGIN=eth0 OUT= MAC= SRC=10.0.0.2
> > DST=255.255.255.255 LEN=328 TOS=0x00 PREC=0x00 TTL=64 ID=0 DF
> > PROTO=UDP SPT=67 DPT=68 LEN=308
> >
> > The server has ip address 10.0.0.2 and the terminal is allocated the
> > address 10.0.0.50.  Any ideas how I can get round this?  Any pointers
> > would be useful and then I could then try messing around with the
> > firewall configuration file.
> >
> > Also, is there a searchable version of the archives for this mailing
> > list?  I have some other questions which I'm sure will already have
> > been answered.
> >
> > Thanks,
> >
> > Joe
> >
> >
> > _____________________________________________________________________
> > 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.openprojects.net
> >



> _____________________________________________________________________
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