martian source messages in the kernel log

My log is showing me these messages....


Oct 23 12:24:07 fw kernel: martian source aaa.bbb.ccc.106 from aaa.bbb.ccc.255, on dev eth1
Oct 23 12:24:07 fw kernel: ll header: 00:03:47:71:87:44:00:90:1a:41:04:60:08:00
Oct 23 12:24:07 fw kernel: martian source aaa.bbb.ccc.107 from aaa.bbb.ccc.255, on dev eth1
Oct 23 12:24:07 fw kernel: ll header: 00:03:47:71:87:44:00:90:1a:41:04:60:08:00

where aaa.bbb.ccc.106 is my main systems ip address and
aaa.bbb.ccc.107 is an IP Alias for my main box.
eth1 is my DSL link.... and 00:03:47:71:87:44 is my mac address for eth1.

Is this telling me that it is hearing my IP Addresses on eth1 on
00:90:1a:41:04:60:08:00 - and why is that an 8 byte mac address not 6?

jack

--
D.A.M. - Mothers Against Dyslexia

see http://www.jacksnodgrass.com for my contact info.

jack - Grapevine/Richardson

Jack Snodgrass wrote:
> My log is showing me these messages....
>
>
> Oct 23 12:24:07 fw kernel: martian source aaa.bbb.ccc.106 from aaa.bbb.ccc.255, on dev eth1
> Oct 23 12:24:07 fw kernel: ll header: 00:03:47:71:87:44:00:90:1a:41:04:60:08:00
> Oct 23 12:24:07 fw kernel: martian source aaa.bbb.ccc.107 from aaa.bbb.ccc.255, on dev eth1
> Oct 23 12:24:07 fw kernel: ll header: 00:03:47:71:87:44:00:90:1a:41:04:60:08:00
>
> where aaa.bbb.ccc.106 is my main systems ip address and
> aaa.bbb.ccc.107 is an IP Alias for my main box.
> eth1 is my DSL link.... and 00:03:47:71:87:44 is my mac address for eth1.
>
> Is this telling me that it is hearing my IP Addresses on eth1 on
> 00:90:1a:41:04:60:08:00 - and why is that an 8 byte mac address not 6?
>
> jack
>

The ll header (logical link, Ethernet here) is split to 6,6,2 bytes:

00:03:47:71:87:44:00:90:1a:41:04:60:08:00

parses to

00:03:47:71:87:44 destination MAC
00:90:1a:41:04:60 source MAC
08:00 payload type (IP)

--

Tauno Voipio
tauno voipio (at) iki fi