Baslinux mailing list

[sindi keesan <keesan AT sdf.lonestar.org>]

On Thu, 7 Dec 2006, sindi keesan wrote:

> > ---------------------------------------------
> > ipchains -P forward DENY
> > ipchains -A forward -s 192.168.1.0/24 -j MASQ
> > ---------------------------------------------
> >
> > You will also probably need to set IP forwarding:
> > ----------------------------------------
> > echo "1" > /proc/sys/net/ipv4/ip_forward
> > ----------------------------------------

Don't need  " " - ipchains told me to type the above line when I forgot 
to.

> Computer on left (BL3 with standard kernel, probably P1)
> insmod 3c59x, ifconfig eth0 192.168.1.1, route add default gw 192.168.1.2
>
> Computer on right (dialed in now) (BL3 with 'big' kernel)
> insmod 3c59x, ifconfig eth0 192.168.1.2, ipchains as above
> echo 1 as above

> What next?  The BL sshd thread petered out, someone was told to compile
> their own, and I would need a password package for BL3 (not for BL2).
>
> I found /bin/telnetd symlinked to the BL3 busybox but if I type telnetd
> it lists busybox functions and it is not included.
>
> It is in my busybox 1.1.10 package and in 1.0.1 compiled by another list
> member (might be glibc version).   No useful help on this.  I used kill to
> unload it.  With the ipchains firewall is telnetd safe to run?  (I can try
> first offline).  How would I use it?  I recall it was complicated via
> serial nullmodem cable.
>
> If I try to telnet to 192.168.1.2 after running telnetd there:
> Connection closed by foreign host.  This is BL3 without a login package.
> I will try BL2.
>
> Sindi

Tried BL2 with bare.i kernel offline first.

insmod 3c59x (ethernet) and ifconfig eth0 192.168.1.1 (computer on left) 
and 192.168.1.2 (computer on right = gateway, dialup connection via it)

busybox 1.1.0 telnetd on the gateway computer
On the other computer, telnet 192.168.1.2, logged in without asking for a 
password (which means I should not be running this telnetd online)
and I could run CLI programs on the gateway computer.

(Please remind me again how to run X programs this way).

On the gateway computer I typed the ipchains lines (three of them 
including echo) to set up a firewall.  On the other computer I typed
route add default gw 192.168.1.2 so I could use the gateway computer to go 
on the internet.  (Neither was needed to telnet between my computers).

I noted the process number of telnetd (48), and dialed in with the 
gateway computer.  While still telnetted with busybox telnet, I could ping 
www.grex.org with the gateway computer and also with the other computer, 
which means both computers were online (via a telnetd that requires no 
password).  My securetty allows root to login via tth1-4, ttyp0-4, ttyS)-3 
ad pts/0 and pts/1.  I may have edited it.  Should I change this so root 
cannot log in via ttypN or is the firewall enough protection?


I typed kill 48 right after testing ping.  How would I know if someone 
tried to access my gateway via telnet in this 10 seconds when telnetd was 
still running after it connected to the internet?

Last time I tried this (with a serial telnet connection) I was not 
vandalized, using some other telnetd and no firewall.

If I use sshd do I need to ssh to the gateway as user rather than root?
Or is this firewall sufficient?