Re: Blocking Port scans

["Ivan ." <ivanhec () gmail com>]

hey

what about the "emb_limit" used with the "static" command?

http://www.cisco.com/en/US/products/sw/secursw/ps2120/products_command_reference_chapter09186a00801cd841.html#wp1026694
The embryonic connection limit lets you prevent a type of attack where
processes are started without being completed. When the embryonic
limit is surpassed, the TCP intercept feature intercepts TCP
synchronization (SYN) packets from clients to servers on a higher
security level.

cheers
Ivan

On 10/24/05, BSK <bishan4u () yahoo co uk> wrote:
> Hello Everyone,
>
> Just wanted some feedback from you people. I'm doing a
> Firewall Assessment for a CISCO PIX firewall. The
> firewall allows SYN, FIN, NULL and XMAS scans but
> blocks ACK scans (largely means its a stateful
> firewall).
>
> Now what do we do to block the scans that are allowed.
> I think it should be easy to block FIN, NULL and XMAS
> scans but how do we block or limit or workaround a SYN
> scan. 1 way that I think is probably blocking or
> limiting  the packets from the source (using IDS/IPS)
>
> Looking ahead to some ideas, thoughts, hints.
>
> thns bshan
>
>
>
>
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