2nd mac address not showing up

2nd mac address not showing up

Post by System Gu » Sun, 09 Aug 1998 04:00:00



we have three systems on a network that each have a default
interface (le0) and an addtional 100BT card on the Sbus (hme0).
in trying to troubleshoot a problem related to*, etc we
started to look at the 100BT interface as the potential trouble
maker.

we discovered that the 100BT card doesn't really show up
anywhere.  when the system boots it only shows the Ethernet
address of the default card in messages or when we look at
dmesg.  the strangest thing is that we totally disabled the
default interface and only brought up the 100BT.  then using
snoop we saw that the MAC address being passed was that of
the default interface even though it wasn't even physically
connected to the network.

does solaris somehow map additional nic cards back to the
default interface mac address no matter what?  it sounds
strange but we checked it several times and this is the
behavior we see.  even when we bring both interfaces up
on unique addresses, the outgoing mac address always seems
to be that of the default interface.  

has anyone seen this before or does anyone have an explanation?

thanks

 
 
 

2nd mac address not showing up

Post by Casper H.S. Dik - Network Security Engine » Sun, 09 Aug 1998 04:00:00


[[ PLEASE DON'T SEND ME EMAIL COPIES OF POSTINGS ]]


>we have three systems on a network that each have a default
>interface (le0) and an addtional 100BT card on the Sbus (hme0).
>in trying to troubleshoot a problem related to*, etc we
>started to look at the 100BT interface as the potential trouble
>maker.

Dd you plug both interfaces into the same net?

You shouldn't, unless you set the MAC address.

Quote:>we discovered that the 100BT card doesn't really show up
>anywhere.  when the system boots it only shows the Ethernet
>address of the default card in messages or when we look at
>dmesg.  the strangest thing is that we totally disabled the
>default interface and only brought up the 100BT.  then using
>snoop we saw that the MAC address being passed was that of
>the default interface even though it wasn't even physically
>connected to the network.

There is no "interface" MAC address, there's a system MAC
address.  All interfaces have the same MAC address, per
the Ethernet spec.

Casper
--
Expressed in this posting are my opinions.  They are in no way related
to opinions held by my employer, Sun Microsystems.
Statements on Sun products included here are not gospel and may
be fiction rather than truth.

 
 
 

2nd mac address not showing up

Post by Michael Busell » Mon, 10 Aug 1998 04:00:00




Quote:>>we discovered that the 100BT card doesn't really show up
>>anywhere.  when the system boots it only shows the Ethernet
>>address of the default card in messages or when we look at
>>dmesg.  the strangest thing is that we totally disabled the
>>default interface and only brought up the 100BT.  then using
>>snoop we saw that the MAC address being passed was that of
>>the default interface even though it wasn't even physically
>>connected to the network.

>There is no "interface" MAC address, there's a system MAC
>address.  All interfaces have the same MAC address, per
>the Ethernet spec.

As stated, all interfaces have the same MAC address by default.  If you
are plugging them both into the same net, you need to set the MAC
address on one of the other interfaces to be something different than
the default.  This can be done with ifconfig, so read the man page on
that for details.

T\_/T\_/T

 
 
 

1. MAC address does not show up on the telco's ARP table caches

// __ 20050915 14:15
 Hi,

 I am using as ISP that uses the telephone/DSL network from the local
telco to provide their clients with broadband/DSL access (they do
provide a better/marginally cheaper service).

 The thing is that I am repeatedly (and way too often) kicked off the
net in ways that even my ISP tech suppost considers to be "very
strange"

 I know I am connected to the Net because if I run ethereal setting my
card on promiscuos mode (I am connecting to the Net directly), I can
see the whole traffic of what is going on on my domain. I must be a
heck of a guesser to make up an ethereal ethernet traffic log.

 They have told me things like:

 ._ your MAC address does not show on the telco's cache.

 ._ your MAC does temporarily show on their ARP table cache
sometimes(?!), but as an imcomplete address

 ._ their ARP tables also show lots of different MAC addresses assigned
to you that are actually not yours

 Also my ISP has a procedure to refresh your NIC's MAC addresses that I
have used to no avail. I have even tried using dirrent NICs on X86
boxes and even a Mac.

 What could be the 'technical' reasons why this could be happening?

 Thanks
 dennishartman

2. This is why RH 6.0 really sucks!

3. showing same mac address for two NIC

4. GPG key-signing parties (again...)

5. ifconfig le0 and ifconfig le1 show same MAC address

6. Q: Audio CODECS & Linux

7. why ifconfig shows two identical MAC address for two different NIC

8. ARP shows client is given wrong MAC Address for system with 2 NICs

9. Adding 2nd NIC - not showing up (3c509b)

10. 2nd IDE channel not showing

11. 2nd NIS server not used when resolving IP addresses

12. Last -l not showing IP addresses