IPCHAINS

[Duncan]

> On July 19, 2004 12:00 am, Duncan wrote:
> > Still this simple firewall is not allowing traffic from me ISP and the
> > CLIENT but traffic on the LAN is flowing , all i want to do is allowa
> > traffic from me to the client , the client has squid so there is no need
> > for masquarading .Hw do i do that with tis firewall.
> >
> > # Setting default to deny all
> >   /sbin/ipchains -P input   DENY
> >   /sbin/ipchains -P output  DENY
> >   /sbin/ipchains -P forward DENY
> >
> >
> > #allowing localhost
> >   /sbin/ipchains -A input  -j ACCEPT -p all -s localhost -d localhost -i
lo
> >   /sbin/ipchains -A output -j ACCEPT -p all -s localhost -d localhost -i
lo
> >
> > #Deny packets from internet claiming to be from localhost and log
> >   /sbin/ipchains -A input  -j REJECT -p all -s localhost  -i ppp0 -l
> >
> > #Deny packets that mimic internal IPs and log
> >   /sbin/ipchains -A input -j REJECT -p all -s clientLAN/24 -i ppp0 -l
> >
> > #Allow packets from ISP
> >   /sbin/ipchains -A input -j ACCEPT -p all -s ISPrange/24  -d
> > ientLAN/24   -i ppp0
> >
> > #Allow packets from LAN
> >   /sbin/ipchains -A output  -j ACCEPT -p all -s client/24 -d
ISPrange/24 -i
> > ppp0
> >
> > #Allow outgoing packets thru internal interface
> >    /sbin/ipchains -A input   -j ACCEPT -p all -s clientLAN/24 -i eth0
> >    /sbin/ipchains -A output  -j ACCEPT -p all -s clientLAN/24 -i eth0
> >
> >
>
> > > ----- Original Message -----
> > > From: "Duncan" <drack at mweb.co.zw>
> > > To: "General Red Hat Linux discussion list" <redhat-list at redhat.com>
> > > Sent: Friday, July 16, 2004 9:10 AM
> > > Subject: IPCHAINS
> > >
> > >
> > > would the following ipchains stop tcp connections from anyone else
other
> > > than iprange , the ips in LAN 195.167.2.0/24
> > >
> > > /sbin/ipchains -F
> > > /sbin/ipchains -P input -p tcp DENY
> > > /sbin/ipchains -A input -p tcp   -s  iprange/24  -d
5.167.2.0/24   -j
> > > ACCEPT
> > > /sbin/ipchains -A input -p udp   -s  iprange/24  -d
5.167.2.0/24   -j
> > > ACCEPT
> > > /sbin/ipchains -A input -p icmp  -s  iprange/24  -d
5.167.2.0/24   -j
> > > ACCEPT
> > >
> > > Please advice
>
> > > ---------------------------
> > > Duncan Rack
>
----- Original Message ----- 
From: "Pete Nesbitt" <pete at linux1.ca>
To: "Duncan" <drack at mweb.co.zw>; "General Red Hat Linux discussion list"
<redhat-list at redhat.com>
Sent: Tuesday, July 20, 2004 3:07 AM
Subject: Re: IPCHAINS
>
> Hi Duncan,
> I'm not sure I understand the whole layout, but if you're using both ppp
and
> Ethernet, you will also need to add FORWARD rules to connect traffic going
> between them (if needed). IPchains was a bit more involved than IPtables
is
> because instead of just having a forward rule for routed packets, IPchains
> requires you set an input->forward->output set of rules.
>
> You may be best to post the exact senario (who is on what interface and
who
> they need to talk to), as well as the whole rules script.
>
> Is there a reason you're using ipchains and not iptables?
> -- 
> Pete Nesbitt, rhce


Hi Pete,

Thanks , the box has RH6.2 , i gues i am kinda of more familiar with
ipchains. The whole idea is to allow the LAN to communicate thru the linux
box with the ISP thru any ports and vice versa and then disallow traffic
from ANY outsider .
1) The linux box already has squid and wat i dont know now is  if i put
forward rules , wont it mean there will be IP masquarading i.e every machine
will be able to browse and do anything and hence complicate the firewall ,
more rules ,port specifications etc...
2) is there anything amiss with the firewall though? its working  as far as
the LAN but when it comes to communicating with the ISP ....NOTHING !!!!

Please help!!!