Old problem still present on 11-ALPHA1 - Pi2

[Hans Petter Selasky]

On 07/11/16 18:15, Karl Denninger wrote:
> I have two PI2s on the same switch here doing quite-different things.
>
> One never shows network problems.  The other one does this:
>
> ....
>
> ukphy0:  none, 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
> ue0: <USB Ethernet> on smsc0
> ue0: Ethernet address: b8:27:eb:08:12:1c
> ugen0.4: <Inateck> at usbus0
> umass0: <Inateck product 0x5136, class 0/0, rev 2.10/0.01, addr 4> on usbus0
> umass0:  SCSI over Bulk-Only; quirks = 0x0100
> umass0:0:0: Attached to scbus0
> da0 at umass-sim0 bus 0 scbus0 target 0 lun 0
> da0: <Inateck  0> Fixed Direct Access SPC-4 SCSI device
> da0: Serial Number 00000000000000000000
> da0: 40.000MB/s transfers
> da0: 476940MB (976773168 512 byte sectors)
> da0: quirks=0x2<NO_6_BYTE>
> random: unblocking device.
> smsc0: chip 0xec00, rev. 0002
> ue0: link state changed to DOWN
> ue0: link state changed to UP
> ue0.2: link state changed to UP
> ue0.3: link state changed to UP
> ue0: link state changed to DOWN
> ue0.2: link state changed to DOWN
> ue0.3: link state changed to DOWN
> ue0: link state changed to UP
> ue0.2: link state changed to UP
> ue0.3: link state changed to UP
> ue0: link state changed to DOWN
> ue0.2: link state changed to DOWN
> ue0.3: link state changed to DOWN
> ue0: link state changed to UP
> ue0.2: link state changed to UP
> ue0.3: link state changed to UP
> ue0: link state changed to DOWN
> ue0.2: link state changed to DOWN
> ue0.3: link state changed to DOWN
> ue0: link state changed to UP
> ue0.2: link state changed to UP
> ue0.3: link state changed to UP
>
> Every now and then (every hour or so) the interface flaps.  If I plug a
> USB interface in and use two network cords I *still* get the flapping.
> This unit has very low (but non-zero) traffic on the network, while the
> other actually has *more* traffic on the network yet is completely
> stable.  Since both are plugged into the same physical switch I doubt
> the switch itself or its firmware is involved in this.
>
> The only difference I can see is that the one that flaps is using
> vlans.  Specifically, that machine is the network's dhcp server, and it
> is on three different vlans (untagged and two tagged) so it can provide
> addresses (and DNS services via unbound) to those VLAN interfaces.
>
> This appears to be somehow linked to the ue interface driver, because
> another machine (Intel based) that is also on multiple vLANs via the em
> driver does *not* flap.
>
> I don't know if this is actually arm related or not; it might not be if
> Intel machines also use the "ue" driver, but it's very consistent on the
> PI2 if I want to use vlan tags whether I have one or two interfaces (the
> second via a USB adapter of course) in use or not.
>
> Other than the flapping the box appears to run fine; the flaps do,
> however, sometimes stop reporting from the snmpd daemon so I have had to
> stick a cron job out there to restart that on a schedule to prevent it
> from interrupting reporting to my traffic management tools.  Whether the
> two are related is not known with certainty (but I suspect it is.)
>

Did you try to set any media options, like 10MBps instead of 100Mbps ?

What does ifconfig say?

--HPS