Bug 21299

Summary:	Primary IP receives datagrams addressed to alias IP address
Product:	Base System	Reporter:	Ronald F. Guilmette <rfg>
Component:	kern	Assignee:	freebsd-bugs (Nobody) <bugs>
Status:	Closed FIXED
Severity:	Affects Only Me
Priority:	Normal
Version:	3.3-RELEASE
Hardware:	Any
OS:	Any

Description Ronald F. Guilmette 2000-09-15 21:50:00 UTC

	Please see detailed bug description at:
	http://www.monkeys.com/bugs/freebsd/2000-09-15.txt

Fix: 

a) None known.
	b) Avoid using ``alias'' IP addresses.
	c) Buy more ethernet cards.
How-To-Repeat: 
	Assign one IP address to an interface, then assign one ``alias'' IP
	address to the same interface.  Run a program which listens for
	incoming UDP datagrams on [xxx.xxx.xxx.xxx].ppppp where the IP
	address xxx.xxx.xxx.xxx is the ``real'' address of the interface,
	and ppppp is some specific port number.  Then send some UDP packets
	(from the outside) to [yyy.yyy.yyy.yyy].ppppp where yyy.yyy.yyy.yyy
	is the alias IP address.  The program that is (ostensibly) listening
	ONLY to [xxx.xxx.xxx.xxx].ppppp will (improperly) receive the packets.

Comment 1 ru freebsd_committer

2000-09-18 10:15:38 UTC

State Changed
From-To: open->closed

Originator writes (http://www.monkeys.com/bugs/freebsd/2000-09-15.txt): 
The bug turned out to be NOT a bug in the FreeBSD kernel at all, but 
merely a misunderstanding on my part relating to BIND 8.2.2 configuration 
directives.