Re: Filtering incoming IP Protocols doesn't work ?

From: Steven L Umbach (n9rou_at_nospam-comcast.net)
Date: 08/21/05 

Date: Sun, 21 Aug 2005 10:54:03 -0500

Tcp/Ip filtering has its uses but is not well understood. For instance as I
mentioned it does not work with ICMP, it blocks inbound only, and it is
stateful for TCP only - not UDP which trips up a lot of users because dns
uses UDP. As Roger said consider ipsec filtering. Ipsec became available in
Windows 2000. Ipsec filtering however should not be considered a full
feature firewall and it is NOT stateful but it is built into the operating
system, can filer ICMP, and can also manage outbound traffic. See the links
below if you are interested in ipsec filtering or ipsec in general. FYI the
main purpose of ipsec is to authenticated computers for network
communications via Security Association and secure traffic with ESP/AH which
can encrypt and insure the integrity on network traffic. --- Steve

http://support.microsoft.com/default.aspx?scid=kb;en-us;313190
http://www.securityfocus.com/infocus/1559
http://www.microsoft.com/windows2000/technologies/communications/ipsec/default.mspx

"Steve" <news_svaardt@hotmail_NOSPAM_.com> wrote in message
news:%23%23N46JkpFHA.1372@TK2MSFTNGP10.phx.gbl...
> Hi Steven
>
> Good article, thanks.
>
> Though the more I encounter these "nuiances" the more I draw parallels to
> buying a used car & finding out the bad news later on... and of course,
> the ubiquitious fine print on the contract says I can't take it back or
> get it fixed.
>
>
> Steve
>
> "Steven L Umbach" <n9rou@nospam-comcast.net> wrote in message
> news:eBMLL5cpFHA.2472@tk2msftngp13.phx.gbl...
>> Tcp/Ip filtering can not block ICMP. See the link below for more
>> ails. -- Steve
>>
>> http://support.microsoft.com/kb/309798
>>
>> "Steve" <news_svaardt@hotmail_NOSPAM_.com> wrote in message
>> news:uwV9MqYpFHA.2976@TK2MSFTNGP12.phx.gbl...
>>> Hello,
>>>
>>> I've setup the "Enable TCP/IP filtering" on my W2K box to only permit IP
>>> Protocols 6 & 17. However my Sygate firewall is still logging incoming
>>> ICMP... why would that be the case ?
>>>
>>> Steve
>>>
>>
>>
>
>

Relevant Pages

  • Re: TCP/IP Filtering Question
    ... For what you are doing you might want to try ipsec filtering policy using ... permit and block fitter actions instead on that router computer. ...
    (microsoft.public.win2000.networking)
  • Re: IPSec for Packet Filtering
    ... Another thing theat IPsec filtering lacks is any protection against IP ... Really, IPSec is OK if used in addition to a firewall, but is ...
    (microsoft.public.security)
  • IPSec Filtering
    ... filters,..port filtering and Ipsec filtering. ... I am running Win2000 advanced servers in an Active ... The Port filtering is fine has I only need to allow Port ... When setting up IPSec filtering on these servers, ...
    (microsoft.public.win2000.security)
  • Re: blocking ip address only one
    ... You need a firewall that can filter inbound traffic more granularly than the ... below has example of ipsec filtering. ... "I'm american not japanese!!!" ...
    (microsoft.public.security)
  • Re: IPSEC firewall
    ... > The IPSec filters will only set filters regarding secure ... You can set the ICMP ... that uses rras filtering driver without actual rras service) ...
    (microsoft.public.win2000.security)
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