Re: [PATCH v2] add stealth mode

From: Matteo Croce
Date: Sun Jul 12 2015 - 19:14:29 EST


2015-07-08 15:32 GMT+02:00 Austin S Hemmelgarn <ahferroin7@xxxxxxxxx>:
> On 2015-07-06 15:44, Matteo Croce wrote:
> Just to name a few that I know of off the top of my head:
> 1. IP packets with any protocol number not supported by your current kernel
> (these return a special ICMP message).

Right, I'll handle them

> 2. SCTP INIT and COOKIE_ECHO chunks when you have SCTP enabled in the
> kernel.

Well, I've never played with SCTP before

> 3. Theoretically, some IGMP messages.
> 4. NDP messages.
> 5. ARP queries looking for the machine's IP addresses.

Yes I know, but it's unlikely to receive this packets from WAN, right?
My flag is intended to be used mostly on WAN interfaces,
machines in LAN should be easily discoverable IMHO

> 6. Certain odd flag combinations on single TCP packets (check the
> documentation for Nmap for more info regarding these), which I believe
> (although I may be reading the code wrong) you aren't accounting for.

I've tried many TCP flags combination with hping3, NUL, SYN/ACK, ACK,
SYN/FIN, etc.
They doesn't get any response when the flag is set

> 7. DAD queries.

Never looked at this packets, are a subset of NDP?

> 8. ICMP address mask queries (which you also don't appear to account for).

It's deprecated and actually it doesn't get any response already

> This is by no means an exhaustive list, but all of them really should be
> addressed if you want to do this properly.
>
>

Thank you,
--
Matteo Croce
OpenWrt Developer
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