On Thu, 4 Oct 2001, Matthew G. Marsh wrote:
> 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.
Sorry, I should have articulated this better. There are two issues here:
1) interface eth4 answers from eth0 (known weak host behaviour, nothing
new here)
2) interface address answers to ping etc. even if the interface has been
brought down.
I should have focused more on 2) in my statement. I believe you answered
to 1).
>
> > 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
> >
> >
>
> --------------------------------------------------
> 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
> --------------------------------------------------
>
--
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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