[THIN] Re: Port Scanning
- From: Henry Sieff <hsieff@xxxxxxxxxxxx>
- To: "'thin@xxxxxxxxxxxxx'" <thin@xxxxxxxxxxxxx>
- Date: Mon, 29 Mar 2004 15:30:03 -0600
If its the same issue I am thinking of, its not actually a caveat, but does
require tuning of the small memory buffers. FWIW, there are also chances
that portscanners can have an effect on cisco equipment; there was a great
one where if you did the sU scan and inclused port 514, a 2600 running
12.0(2) would simply reload.
In almost all cases that I am familiar with, the issue arises not when hosts
are scanned through a router/layer3 switch, but when the device itself is
scanned. Usually, there are specific actions which can be taken to mitigate.
Henry
> -----Original Message-----
> From: Timothy Mangan [mailto:tmangan@xxxxxxxxxxxx]
> Sent: Monday, March 29, 2004 3:09 PM
> To: thin@xxxxxxxxxxxxx
> Subject: [THIN] Re: Port Scanning
>
>
> They really should fix that - it has been a problem for many
> years now.
> It's really a packet rate thing. You can pound it with any
> small packets to
> hose up the router. I've seen it done with both bisync and
> icmp traffic.
>
> tim
>
> -----Original Message-----
> From: thin-bounce@xxxxxxxxxxxxx
> [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
> Of Ryan Lambert
> Sent: Monday, March 29, 2004 3:13 PM
> To: thin@xxxxxxxxxxxxx
> Subject: [THIN] Re: Port Scanning
>
> Hi James,
>
> UDP scanning with nmap (-sU) has been known to crash Cisco IOS version
> 12.0T, 12.0S, etc.
>
> -----Original Message-----
> From: James A. Hayes [mailto:jhayes@xxxxxxxxxxxxxxxxxx]=20
> Sent: Monday, March 29, 2004 2:10 PM
> To: thin@xxxxxxxxxxxxx
> Subject: [THIN] Port Scanning
>
> Has anyone seen where port scanning caused major network issues? Our
> security officer runs port scans on our network when ever she wants to
> and
> it never fails that our network then chugs down to a complete halt and
> we
> have to reboot our core switch to correct the problem. Any ideas or
> suggestions?
> =20
>
> James A. Hayes
>
> Network Operations Manager & Assistant Vice-President
>
> The Peoples Bank & Trust Company
>
> =20
>
> (work) 662.680.1667
>
> (mobile) 662.401.0750
>
> (fax) 662.680.1502
>
> =20
>
> =20
>
>
>
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