Security Basics mailing list archives
RE: what's the meaning of the 0.0.0.0?
From: "David Gillett" <gillettdavid () fhda edu>
Date: Mon, 28 Jul 2003 10:10:59 -0700
Just as 255.255.255.255 is interpreted as "the broadcast address of whatever network I'm on", 0.0.0.0 should usually mean "the network address of whatever network I'm on". Which raises the questions of: 1. If I have more than one interface, which one should I send this to? 2. How do I translate this layer 3 destination (IP address) into a layer 2 destination (MAC address)? Network addresses are reserved, but their useful implementation has not really been defined. So question #1 means that routing this traffic to the loopback interface is defensible, and question #2 means that sending it as a local broadcast is defensible. (0.0.0.0 might also be set/reported as the source address in a DHCP request, because the station does not yet have an assigned IP address. Note that in this case it is the source, and it's the destination address that determines how the questions above get answered.) David Gillett
-----Original Message----- From: Fernando Gont [mailto:fernando () gont com ar] Sent: July 25, 2003 12:35 To: security-basics () securityfocus com Subject: RE: what's the meaning of the 0.0.0.0? At 15:42 24/07/2003 -0400, you wrote:In linux machines when you try to connect to 0.0.0.0 it goes to localhost ...A bug, perhaps?And in my last email i said that its a broadcast because it is going to "all" ips in this "broadcast domain*"...The 0.0.0.0 is *not* the broadcast address. I think this could only be possible on old BSD systems, that used zero's instead of one's for broadcast addresses. -- Fernando Gont e-mail: fernando () gont com ar || fgont () acm org -------------------------------------------------------------- ------------- -------------------------------------------------------------- --------------
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Current thread:
- RE: what's the meaning of the 0.0.0.0? Fernando Gont (Jul 24)
- <Possible follow-ups>
- RE: what's the meaning of the 0.0.0.0? Dave Killion (Jul 24)
- RE: what's the meaning of the 0.0.0.0? Daniel B. Cid (Jul 24)
- RE: what's the meaning of the 0.0.0.0? Fernando Gont (Jul 28)
- RE: what's the meaning of the 0.0.0.0? David Gillett (Jul 28)
- RE: what's the meaning of the 0.0.0.0? stephen at unix dot za dot net (Jul 30)
- RE: what's the meaning of the 0.0.0.0? David Gillett (Jul 30)