In an attempt to stack ALIX boards using their USB interfaces
(actually to emulate an MPLS core in the lab with three ALIX boards
connected in a triangle as P routers over 480 Mbit/s USB "core"
links), I picked up a USB to USB bridge at the local supermarket.
This 20$ USB bridge is branded "connection, ednet elecom Group, USB
Easy Datalink, USB 2.0 Link Cable A/A, Art.-No. 84256". I was gambling
that it has a chipset built-in which is supported by cdce(4), such as
the Prolific PL250x. It looks as if I am without luck and its OTi
chipset (OTi002108-G ?) is not (yet) supported.
On i386-current, it appears as a SCSI drive which holds an executable
file for Windows, much like 2G/3G adapters like umsm(4) do:
# dmesg
...
umass1 at uhub1 port 1 configuration 1 interface 0 "USB Transfer line"
rev 2.00/1.00 addr 3
umass1: using SCSI over Bulk-Only
scsibus2 at umass1: 2 targets, initiator 0
sd1 at scsibus2 targ 1 lun 0: <OTi, Thunderbird, 1.00> SCSI2 0/direct removable
sd1: 0MB, 512 bytes/sec, 992 sec total
...
# mount /dev/sd1i /mnt
# ls -al /mnt
-rwxr-xr-x 1 root wheel 409600 Nov 16 2005 EasySuite.exe
# usbdevs -v
...
port 1 addr 3: high speed, power 250 mA, config 1, Transfer
line(0x2108), USB(0x0ea0), rev 1.00
...
After manually adding the new device to usbdevs, it attaches to cdce0
in the freshly built kernel:
# dmesg
...
cdce0 at uhub0 port 1 configuration 1 interface 0 "USB Transfer line"
rev 2.00/1.00 addr 2
cdce0: address 2a:cb:05:b8:12:00
...
# ifconfig cdce0 10.8.0.11 netmask 255.255.255.0 up
# ifconfig cdce0
cdce0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
lladdr 2a:cb:05:b8:b3:00
priority: 0
inet6 fe80::28cb:5ff:feb8:b300%cdce0 prefixlen 64 scopeid 0x6
inet 10.8.0.11 netmask 0xffffff00 broadcast 10.8.0.255
But pinging the peer on the other end of the USB bridge fails, which
has got the link local address 2a:cb:05:b8:12:00 :
# dmesg
...
cdce0: usb error on rx: STALLED
...
Did eventually anyone tried to integrate this USB bridge into cdce(4)
before? Is there anything else I should try before giving up on this
particular USB bridge cable, and to stack ALIX boards using their USB
ports (in order to save the 3 Ethernet NICs to connect more ALIX
boards as PE routers to the MPLS core :-)?
Thanks for any hints,
Rolf
