DPAA Ethernet traffice troubles with Linux kernel

mad skateman madskateman at gmail.com
Wed Jan 17 05:44:41 AEDT 2018


Hi,

I have been looking deeper into my wireshark packet captures and found
something that could be helpfull.

I can see that the Ethernet NIC at least does something. ARP BROADCAST
traffic is seen.
But i also found some packets...which have LG BITs set to 1 .. when i think
0 should be the correct value..something with Octets.

*"the first 3 octets/first-half of a MAC-48/EUI-48 Address, correspond to
the OUI (e.g.: MAC = 06:00:00:xx:xx:xx, OUI = 06:00:00), and the 2nd least
significant bit of its first octet is used to differentiate "Universally"
and "Locally" administered addresses). In other words, if we convert 06
(Hex) to 00000110 (Binary), we can see that the U/L bit is set to one,
which means that it a locally administered address.*

*Given this if we disable that bit, we get the matching "Universally
Administered Address" 00000100 (Binary), 04 (Hex) -> "04:00:00", hence my
question:"*

This has something to do with the MAC adresses being locally administered
.. and since whe can use Uboot and choose any Mac addr we want, this could
make sense..

These types of Logs also apear in my Wireshark Capture files... ( these are
not my org. logs)

Ethernet II, Src: Microchi_8f:c6:a8 (d8:80:39:8f:c6:a8), Dst: Broadcast
(ff:ff:ff:ff:ff:ff)
Destination: Broadcast (ff:ff:ff:ff:ff:ff)
Address: Broadcast (ff:ff:ff:ff:ff:ff)
.... ..1. .... .... .... .... = LG bit: Locally administered address (this
is NOT the factory default)
.... ...1 .... .... .... .... = IG bit: Group address (multicast/broadcast)
Source: Microchi_8f:c6:a8 (d8:80:39:8f:c6:a8)
Address: Microchi_8f:c6:a8 (d8:80:39:8f:c6:a8)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory
default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Type: IP (0x0800)
Internet Protocol Version 4, Src: 0.0.0.0 (0.0.0.0), Dst: 255.255.255.255
(255.255.255.255)

In the link below some similair Logs and problems regarding DHCP for
example.

Dave
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