ip allmulti oddity (was: promiscuous mode)
Hi,
This might be just marginally security related, but here it goes.
Got curious about this and looked around. Checked ifconfig and ip
(iproute2).
,----
| # ifconfig eth1
| eth1 Link encap:Ethernet HWaddr 00:80:c8:ca:4e:96
| UP BROADCAST RUNNING MTU:1500 Metric:1
`----
Yes, I switch off multicast using either:
# ifconfig eth1 -multicast
or
# ip link set eth1 multicast off
,----
| # ip link show eth1
| 3: eth1: <BROADCAST,ALLMULTI,UP> mtu 1500 qdisc pfifo_fast qlen 100
| link/ether 00:80:c8:ca:4e:96 brd ff:ff:ff:ff:ff:ff
`----
Notice the ALLMULTI flag here above.
I can manipulate the flag using ifconfig, but I found out I can't do that
using the distributed ip. Although ip shows the flag (even when ifconfig
doesn't), it can't handle it :(
,----
| # ip link help
| Usage: ip link set DEVICE { up | down | arp { on | off } |
| dynamic { on | off } |
| multicast { on | off } | txqueuelen PACKETS |
| name NEWNAME |
| address LLADDR | broadcast LLADDR |
| mtu MTU }
| ip link show [ DEVICE ]
`----
This is the sid distributed package:
,----
| Package: iproute
| Maintainer: Juan Cespedes <cespedes@debian.org>
| Version: 20010824-9
`----
which is old, and I suspect this is an ip bug. Newer version(s) which
document support for ALLMULTI:
,----
| ip link set DEVICE { up | down | arp { on | off } |
| promisc { on | off } |
| allmulti { on | off } |
| dynamic { on | off } |
| multicast { on | off } |
| txqueuelen PACKETS |
| name NEWNAME |
| address LLADDR | broadcast LLADDR |
| mtu MTU }
`----
are available.
Does anyone know of any particular reason why the iproute package is not
yet updated (to a less buggy version)?
Cheers,
Cristian
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