Arp-poisoning help!

zaheer · 07-22-2007, 02:16 PM

Hi allz,

I am client of a LAN network and our gateway is a Linux Machine.Some one locally is arp-poisoning our network and our network admin (dumb***)don't know what to do.He only gave us a windows self made service file which when windows boots starts.Now for my linux machine I have two more computer's behind a smoothwall firewall and for this he said to type arp - s {Ip Of Server} {Mac Address Of Server}.Now what can I do to avoid this arp poisoning on our network and how can I add a scipt to smoothwall which on boot get run this command.I know in redhat it rc.local but in smoothwall I can't find rc.local

macemoneta · 07-22-2007, 11:27 PM

Set the values in /etc/ethers; 'man ethers':

Quote:

/etc/ethers contains 48 bit Ethernet addresses and their corresponding
IP numbers, one line for each IP number:

Ethernet-address IP-number

The two items are separated by any number of SPACE and/or TAB char
acters. A # at the beginning of a line starts a comment which extends
to the end of the line. The Ethernet-address is written as
x:x:x:x:x:x, where x is a hexadecimal number between 0 and ff which
represents one byte of the address, which is in network byte order
(big-endian). The IP-number may be a hostname which can be resolved by
DNS or a dot separated number.

zaheer · 07-23-2007, 12:38 AM

What values should i set in this file
etc/ethers ???

macemoneta · 07-23-2007, 12:44 AM

Take the command your admin sent:

arp - s {Ip Of Server} {Mac Address Of Server}

And put in the file:

{Mac Address Of Server} {Ip Of Server}

zaheer · 07-23-2007, 12:49 AM

Ok,Should I have to remove arp -s before putting it in /etc/ethers ?

macemoneta · 07-25-2007, 10:34 PM

The two do the same thing. You can either change the local init file to run the command or add the MAC/IP to the ether file.