Re: Allow ICMP on external interface
- From: "William Robertson" <robertson.william@xxxxxxxxxxxxxx>
- To: "'[ISAserver.org Discussion List]'" <isalist@xxxxxxxxxxxxx>
- Date: Wed, 1 Oct 2003 07:56:43 +0200
Hi Han
I would agree with you that PING is a very handy tool when trying to verify
connectivity etc, but after the last spate of DoS attacks with the Nachi
worm etc, I am sure that you would concede that it is not the wisest thing
these days to actually allow inbound ICMP willy-nilly.
My suggestion to you is to do what I do, and that is to create the ICMP
Inbound packet filters for each of your interfaces, but then to leave them
in a disabled state. And only when you need to verify some connectivity
issue, then enable the packet filters for that limited time period.
This mode of operation has proved very useful for me and I would strongly
recommend that you heed Jim's warning about "allowing the simplest of DoS
attacks.
Cheers
William R.
-----Original Message-----
From: Han Valk [mailto:Han.Valk@xxxxxxxxxxxxxxx]
Sent: 01 October 2003 06:43 AM
To: [ISAserver.org Discussion List]
Subject: [isalist] Re: Allow ICMP on external interface
http://www.ISAserver.org
> -----Original Message-----
> From: Jim Harrison [mailto:jim@xxxxxxxxxxxx]
> Sent: Wednesday, October 01, 2003 01:50
> To: [ISAserver.org Discussion List]
> Subject: [isalist] Re: Allow ICMP on external interface
>
>
> http://www.ISAserver.org
>
>
> Why do folks always want to allow the simplest of DoS attacks?
> <sigh>
>
Hi Jim,
I'm sorry to hear that your opinion is to block ICMP. I know there are other
people that have the same opninion but I also know a lot of people who don't
agree with you. PING is a very handy tool.
Best regards,
Han Valk.
------------------------------------------------------
List Archives: http://www.webelists.com/cgi/lyris.pl?enter=isalist
ISA Server Newsletter: http://www.isaserver.org/pages/newsletter.asp
ISA Server FAQ: http://www.isaserver.org/pages/larticle.asp?type=FAQ
------------------------------------------------------
Other Internet Software Marketing Sites:
Leading Network Software Directory: http://www.serverfiles.com
No.1 Exchange Server Resource Site: http://www.msexchange.org
Windows Security Resource Site: http://www.windowsecurity.com/
Network Security Library: http://www.secinf.net/
Windows 2000/NT Fax Solutions: http://www.ntfaxfaq.com
------------------------------------------------------
You are currently subscribed to this ISAserver.org Discussion List as:
robertson.william@xxxxxxxxxxxxxx
To unsubscribe send a blank email to $subst('Email.Unsub')
---------------------------------------------------------------------
Everything in this e-mail and attachments relating to the official
business of Columbus Stainless is proprietary to the company. It is
confidential, legally privileged and protected by law. Columbus
Stainless does not own and endorse any other content. Views and
opinions are those of the sender unless clearly stated as being that
of Columbus Stainless. The person addressed in the e-mail is the sole
authorised recipient. Please notify the sender immediately if it has
unintentionally reached you and do not read, disclose or use the
content in any way. Whilst all reasonable steps are taken to ensure
the accuracy and integrity of information and data transmitted
electronically and to preserve the confidentiality thereof, no
liability or responsibility whatsoever is accepted if information or
data is,for whatever reason, corrupted or does not reach its intended
destination.
---------------------------------------------------------------------
Other related posts:
