Subject: kern/21633: packets originate from previous IP address after changing it
To: None <>
From: None <>
List: netbsd-bugs
Date: 05/21/2003 16:08:58
>Number:         21633
>Category:       kern
>Synopsis:       packets originate from previous IP address after changing it
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed May 21 06:10:01 UTC 2003
>Originator:     grant beattie
>Release:        NetBSD 1.6T
NetBSD u10 1.6T NetBSD 1.6T (GENERIC) #0: Sun May 18 20:52:48 EST 2003  autobuild@mofo:/data1/netbsd/autobuild/current/obj.sparc64/sys/arch/sparc64/compile/GENERIC sparc64
Architecture: sparc64
Machine: sparc64
after killing dhclient and changing the IP address of the hme0 interface,
I noticed packets still continue to originate from the old address.
unsurprisingly, those connections fail. connections to the new address
work fine.

the machine has been left in this state overnight and the problem still

tcpdump shows packets originating from the old address, ifconfig reports
the new address correctly.

15:46:14.523970 >  53701+ AAAA? (34)
15:46:19.530169 >  53701+ AAAA? (34)
15:46:29.540147 >  53701+ AAAA? (34)
15:46:49.550272 >  53701+ AAAA? (34)

u10: {71} ifconfig hme0
        address: 08:00:20:9f:0f:17
        media: Ethernet autoselect (100baseTX full-duplex)
        status: active
        inet netmask 0xffff0000 broadcast
        inet6 fe80::a00:20ff:fe9f:f17%hme0 prefixlen 64 scopeid 0x1

the workaround is to reboot.

change the IP address of an interface, notice that packets originate
from the old address.