[Dnsmasq-discuss] --script-arp question

[0zl]

On 4/12/23 09:09, 0zl wrote:
> On 4/12/23 08:19, Geert Stappers wrote:
>> On Wed, Apr 12, 2023 at 02:03:22AM +0300, 0zl wrote:
>>> On 4/12/23 01:59, 0zl wrote:
>>>> Second I don't understand how this works exactly, I intend to create a
>>>> script that adds a permanent arp entry to make me more resilient to ARP
>>>> spoofing attacks, should I create the entry on arp add/old and remove on
>>>> del; OR use these arp-add and arp-del actions to do the same.
>>> Replying to myself because I made a typo in this paragraph. I meant to say:
>>> "should I create the ARP entry on the add/old action and remove on del"
>> Experiment
>>
>>
>> Groeten
>> Geert Stappers
>
> This dhcp-script seems to work just fine, not sure what the point of 
> arp-add/arp-del is though:
>
> #!/bin/sh
> action=$1 hw_addr=$2 hostname=$3
> case $action in
> 	add|old) arp -s $hostname $hw_addr ;;
> 	del)     arp -d $hostname          ;;
> esac
>
>
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UPDATE: `--script-arp` is ABSOLUTELY not what you want in this case. 
What it does is execute the dhcp-script with arp-add/del action whenever 
a new entry to the ARP table is added, that includes those spoofed/not 
authorized by the DHCP server (I've just tested it). What is needed in 
this case is the add/old and del events, DO NOT use --script-arp in this 
case.

Best regards
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