On Thu, 4 Oct 2001, Pekka Savola wrote:
> Hi,
>
> With 2.2.18 I noticed something that looked interesting:
>
> # /sbin/ip a l dev eth4
> 7: eth4: <BROADCAST,MULTICAST,PROMISC> mtu 1500 qdisc pfifo_fast qlen 100
> link/ether 00:80:c8:c9:b8:14 brd ff:ff:ff:ff:ff:ff
> inet x.y.7.252/24 brd x.y.7.255 scope global eth4
>
> Note that the interface is not UP. Whether it's promisc or not does not
> affect this.
True. Any address on the system will be responded to by any interface. I
use this all the time to assign addresses to dummy that are not advertised
but are available.
> However, the address is still pingable from outside, through eth0!
>
> Also noticed the same behaviour in 2.4.10.
>
> Is this the intended behaviour, probably?
>
> One could argue that if interface isn't UP, it shouldn't be able to send
> or receive packets at all. I wonder what changing this would break..
>
> --
> Pekka Savola "Tell me of difficulties surmounted,
> Netcore Oy not those you stumble over and fall"
> Systems. Networks. Security. -- Robert Jordan: A Crown of Swords
>
>
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Matthew G. Marsh, President
Paktronix Systems LLC
1506 North 59th Street
Omaha NE 68104
Phone: (402) 932-7250 x101
Email: mgm@xxxxxxxxxxxxx
WWW: http://www.paktronix.com
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