Re: blocked address

From: *Vanguard* (no-email_at_no-spam.invalid)
Date: 02/25/04 

Date: Wed, 25 Feb 2004 16:44:25 -0600

"gorkin" said in news:c1ip32$23tk$1@bowmore.utu.fi:
> Hi! I got these port scans from ip 169.254.144.251 and when i tried
> to do traceroute it said assigned by IANA for use in private internets
> [blocked]...what the hell does this mean?...i also tried pinging
> whois etc etc using various sites online offerring this kind of
> stuff...all I found out is that they have their ports 80 and 53 (UDP)
> open...
>
> thanks.

APIPA

Short for Automatic Private IP Addressing, a feature of later Windows
operating systems. With APIPA, DHCP clients can automatically self-configure
an IP address and subnet mask when a DHCP server isn't available. When a
DHCP client boots up, it first looks for a DHCP server in order to obtain an
IP address and subnet mask. If the client is unable to find the information,
it uses APIPA to automatically configure itself with an IP address from a
range that has been reserved especially for Microsoft. The IP address range
is 169.254.0.1 through 169.254.255.254. The client also configures itself
with a default class B subnet mask of 255.255.0.0. A client uses the
self-configured IP address until a DHCP server becomes available.
The APIPA service also checks regularly for the presence of a DHCP server
(every five minutes, according to Microsoft). If it detects a DHCP server on
the network, APIPA stops, and the DHCP server replaces the APIPA networking
addresses with dynamically assigned addresses.

APIPA is meant for nonrouted small business environments, usually less than
25 clients. 

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