>Number:         7489
>Category:       kern
>Synopsis:       "permanent" ARP entries can be overwritten
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people (Kernel Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Apr 28 13:35:00 1999
>Last-Modified:
>Originator:     Rhialto
>Organization:
	
>Release:        1.3.3
>Environment:
	
System: NetBSD polder 1.3.3 NetBSD 1.3.3 (ROUTER) #13: Sun Apr 25 17:56:09 CEST 1999 rhialto@polder:/usr/src/sys/arch/i386/compile/ROUTER i386


>Description:
	
	I had configured a gateway to respond to several IP addresses
	for purposes of NAT. To do that I needed to add ARP entries
	for these IP addresses corresponding to the appropriate
	Ethernet address.

	Then an incorrectly configured machine came along, set to one
	of the same IP adresses. The "permanent" ARP entry for this IP
	address was overwritten and of course never restored.

	Lossage ensued.
>How-To-Repeat:
	
	# arp -s ipaddr etheraddr pub
	configure another machine to use the same ip addr
	watch the "permanent" ARP entry get overwritten.

	
>Fix:
	
	None supplied.
>Audit-Trail:
>Unformatted: