[unisog] Port 0

Ken Connelly Ken.Connelly at uni.edu
Thu Oct 27 15:46:00 GMT 2005

ICMP doesn't have a port associated with it.  ICMP packets have a type 
and often a code, but not a port.  See 
http://www.iana.org/assignments/icmp-parameters for details.

And it wouldn't be a good thing to simply block all ICMP packets.

- ken

Christensen, Eric wrote:

>I was reviewing my firewall logs this morning and found a few packets going
>to and from port 0.  Apparently they were ICMP packets.  I think that is
>probably legitimate but I'm thinking that many computers might accept these
>packets thinking they are legit when they are really attacks.  If they are
>just ICMP packets you could just block them.  Right?
>Eric Christensen
>Technology Support Specialist
>ECU Police Department
>608C E 10th St
>Greenville NC 27858-4353
>(252)328-1155 - Office
>(252)328-6787 - 911 Communications
>(252)328-6965 - Fax
>unisog mailing list
>unisog at lists.sans.org

- Ken
Ken Connelly Systems and Operations Manager, ITS Network Services
University of Northern Iowa           Cedar Falls, IA  50614-0121
email: Ken.Connelly at uni.edu
phone: (319) 273-5850   fax: (319) 273-7373

It's much more important to know what you don't know than what you do know!

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