2:13 p.m.
I was surprised recently when I tried xsane and discovered that
it actually worked these days on my Epson Artisan 725 connected
via the network.
But I tried to use it again today, and found that xsane claims
it can't find any scanners.
I cranked up the Windows virtual machine and it talked to
it just fine.
Was fedora just teasing me the other day?
Any way to build in the known scanner IP addr instead of
relying on it scanning for devices?
I tried adding the IP addr to /etc/sane.d/net.conf, but nothing
changed.
2:22 p.m.
On Tue, 27 Jul 2021 15:13:03 -0400
Tom Horsley wrote:
I tried adding the IP addr to /etc/sane.d/net.conf, but nothing
changed.
Never mind. I rebooted the router and it works now. I've noticed
a lot of weirdness with this router (Netgear Nighthawk RAX200)
and routing between wired and wireless devices on my local network.
You'd think a top of the line router could get that right :-(.
6:08 p.m.
On 27Jul2021 15:22, Tom Horsley <horsley1953(a)gmail.com> wrote:
Never mind. I rebooted the router and it works now. I've noticed
a lot of weirdness with this router (Netgear Nighthawk RAX200)
and routing between wired and wireless devices on my local network.
You'd think a top of the line router could get that right :-(.
We've got a few unmanaged netgear switches here and have had some
weirdness ourselves. I have lossely discovered that having my Mac on
both ethernet and wifi at once causes the LAN to go sour.
I imagine a Linux system might do similar stuff (I know from bitter
experience that the Linux IP stack default behaviour answers on any
interface for any of its IP addresses, causing hard to debug pain if you
plugged in multiple ethernets to the wrong ports.)
My theory (unverified as yet, but supported by "did you just plug in
your ethernet? the internet's gone away!" complaints) is that the Mac
answers ARP requests on both the wifi and the LAN, suggesting to the
switches watching traffic that (say) its ethernet address is also
available on the wifi, and/or vice versa.
The local network topology is like this:
fw ---- desk-switch ----living-room-switch ---- airport-wifi
|
+--- secondary-switch ---- mac-ethernet
This might confuse the desk switch about where to send packets for the
Mac and seemed to have secondary effects for other users of the LAN
(loss of local connectivity). I'm imagining the MAC<->port tables in the
switches became insane.
Now I run my Mac in wifi only or LAN only, and the problem has gone.
Cheers,
Cameron Simpson <cs(a)cskk.id.au>
6:37 p.m.
On Mon, 2 Aug 2021 09:08:30 +1000
Cameron Simpson wrote:
Now I run my Mac in wifi only or LAN only, and the problem has gone.
I've always had the wireless turned off in my desktop, which is
the only system I have that might possibly try to enable both.
Just checked "ip addr" and there is a wlan, but it has no assigned
IP. I did get a new RAX 200 firmware just a couple of days ago, and
I haven't noticed a problem yet, but I don't have a very big
sample size either.
9:37 p.m.
On Mon, 2021-08-02 at 09:08 +1000, Cameron Simpson wrote:
We've got a few unmanaged netgear switches here and have had
some
weirdness ourselves. I have lossely discovered that having my Mac on
both ethernet and wifi at once causes the LAN to go sour.
This might confuse the desk switch about where to send packets for
the Mac and seemed to have secondary effects for other users of the
LAN (loss of local connectivity). I'm imagining the MAC<->port tables
in the switches became insane.
Though, this shouldn't really be a problem (in a perfect world
scenario).
A device with multiple connections ought to be prioritising them in
some way (and I'd certainly rank wired interfaces above wireless). Then
trying to use that interface in preference. Or in some cases, you
might want to have plugging in the wired interface automatically
disconnecting the wireless interface.
Your two interfaces should (nay must) have different MACs, likewise
with numerical IPs. Any routers and switches should be aiming return
traffic back at the same interface.
--
uname -rsvp
Linux 5.11.22-100.fc32.x86_64 #1 SMP Wed May 19 18:58:25 UTC 2021 x86_64
Boilerplate: All unexpected mail to my mailbox is automatically deleted.
I will only get to see the messages that are posted to the mailing list.
1:04 a.m.
On 2021-08-01 7:37 p.m., Tim via users wrote:
A device with multiple connections ought to be prioritising them in
some way (and I'd certainly rank wired interfaces above wireless). Then
trying to use that interface in preference. Or in some cases, you
might want to have plugging in the wired interface automatically
disconnecting the wireless interface.
Your two interfaces should (nay must) have different MACs, likewise
with numerical IPs. Any routers and switches should be aiming return
traffic back at the same interface.
I usually configure dhcp to give the same IP address to both the
ethernet and wifi interfaces. This lets you disconnect the ethernet and
move around without losing connections. And makes it easy to find the
device remotely however it's connected. Many years ago this did
sometimes have issues, but for at least several years this has been
working perfectly. The ethernet connection has priority, so connections
will use it if it's connected.
7:09 a.m.
On Mon, 2 Aug 2021 at 03:04, Samuel Sieb <samuel(a)sieb.net> wrote:
On 2021-08-01 7:37 p.m., Tim via users wrote:
> A device with multiple connections ought to be prioritising them in
> some way (and I'd certainly rank wired interfaces above wireless). Then
> trying to use that interface in preference. Or in some cases, you
> might want to have plugging in the wired interface automatically
> disconnecting the wireless interface.
My desktop has both wifi and ethernet active, with different IP's. I use it
with a wifi to ethernet bridge for connecting gear that doesn't have wifi
(easier than figuring out how to have a temporary long cable that won't get
tangled up with dogs).
>
> Your two interfaces should (nay must) have different MACs, likewise
> with numerical IPs. Any routers and switches should be aiming return
> traffic back at the same interface.
I usually configure dhcp to give the same IP address to both the
ethernet and wifi interfaces. This lets you disconnect the ethernet and
move around without losing connections. And makes it easy to find the
device remotely however it's connected. Many years ago this did
sometimes have issues, but for at least several years this has been
working perfectly. The ethernet connection has priority, so connections
will use it if it's connected.
My POE switch stopped providing POE to the access points
(except the one in the master bedroom, which lit up a 2AM).
This happened a few weeks past the 3-year warranty period,
corresponding to the start of the Olympics! Given that power
went off and came back for one AP, I suspect software rather
than a hardware failure, but the vendor's tech people couldn't
find a way to get the POE back, so the switch was replaced.
I tried providing wifi with a couple old Apple Airport Extremes (AAE,
normally
used with wifi off as ethernet bridges). This worked for a few hours, then
devices were reporting no internet access, and the AAE's had 169.254
addresses.
The replacement POE switch (different maker) worked fine except that TV
set-side
boxes wouldn't work. Fortunately, it was easy to move them to the ISP's
router.
All this reminds me of
https://www.alfredtong.com/cisco/cisco-switch-causes-duplicate-ip-address...
which once caused headaches for a workshop I was teaching.
--
George N. White III
8:47 a.m.
On Sun, 2021-08-01 at 23:04 -0700, Samuel Sieb wrote:
I usually configure dhcp to give the same IP address to both the
ethernet and wifi interfaces. This lets you disconnect the ethernet
and move around without losing connections. And makes it easy to
find the device remotely however it's connected. Many years ago this
did sometimes have issues, but for at least several years this has
been working perfectly. The ethernet connection has priority, so
connections will use it if it's connected.
I did try that long ago, and found it caused problems trying to give
the same IP to two different ports.
Even on things that really should be able to handle that kind of thing,
such as a mobile phone using WiFi around premises with two access
points, using the same SSIDs and passphrases, both connected to the
same DNS and DHCP server by cable, they wouldn't do the desired thing.
They'd always try to keep using the same access point. And on the few
times they'd flip over, all traffic got halted and had to be manually
restarted.
--
uname -rsvp
Linux 3.10.0-1160.36.2.el7.x86_64 #1 SMP Wed Jul 21 11:57:15 UTC 2021 x86_64
Boilerplate: All unexpected mail to my mailbox is automatically deleted.
I will only get to see the messages that are posted to the mailing list.
10:30 a.m.
On Mon, 2 Aug 2021 at 10:47, Tim via users <users(a)lists.fedoraproject.org wrote:
which made moving around seamless, even when streaming video.
Now there is
a significant delay when moving to a part of the house where the AP I was
using
has a weak signal. My wife spends a lot of time in zoom meetings and
sometimes
needs to change location to during meetings, so
The original 802.11r <https://en.wikipedia.org/wiki/IEEE_802.11r-2008> has
a flawed protocol. I'm not sure if 802.11r has been disabled or changed
in some
way that my devices don't support.
There is a site that collects vendor responses to the 802.11r problems, but
my
AP vendor had not responded last time I checked. <
https://github.com/WLAN-Pi/profiler can check
devices for 802.11r support
--
George N. White III
Even on things that really should be able to handle that kind of thing,
such as a mobile phone using WiFi around premises with two access
points, using the same SSIDs and passphrases, both connected to the
same DNS and DHCP server by cable, they wouldn't do the desired thing.
They'd always try to keep using the same access point. And on the few
times they'd flip over, all traffic got halted and had to be manually
restarted.
Until recently, my AP's supported 802.11r <
https://www.networkcomputing.com/wireless-infrastructure/wifi-fast-roamin...
8:04 a.m.
On 2021-08-01 7:08 p.m., Cameron Simpson wrote:
On 27Jul2021 15:22, Tom Horsley <horsley1953(a)gmail.com> wrote:
> Never mind. I rebooted the router and it works now. I've noticed
> a lot of weirdness with this router (Netgear Nighthawk RAX200)
> and routing between wired and wireless devices on my local network.
> You'd think a top of the line router could get that right :-(.
We've got a few unmanaged netgear switches here and have had some
weirdness ourselves. I have lossely discovered that having my Mac on
both ethernet and wifi at once causes the LAN to go sour.
. . .
Huh? Am I misinterpreting? The MAC is supposed to be world-wide unique
to each interface. There are a couple of situations where this can
accidentally happen, like VMware using the same poorly-chosen random MAC
for two VMs that breaks everything on that vSwitch, but that's the only
one that I've ever encountered. Having the same MAC on two interfaces is
not legal, so you should expect to break something on any router or
machine that I can think of. If it works, then that router is broken.
--
John Mellor
8:20 a.m.
On Mon, 2021-08-02 at 09:04 -0400, John Mellor wrote:
On 2021-08-01 7:08 p.m., Cameron Simpson wrote:
> On 27Jul2021 15:22, Tom Horsley <horsley1953(a)gmail.com> wrote:
> > Never mind. I rebooted the router and it works now. I've noticed
> > a lot of weirdness with this router (Netgear Nighthawk RAX200)
> > and routing between wired and wireless devices on my local
> > network.
> > You'd think a top of the line router could get that right :-(.
> We've got a few unmanaged netgear switches here and have had some
> weirdness ourselves. I have lossely discovered that having my Mac
> on
> both ethernet and wifi at once causes the LAN to go sour.
>
> . . .
Huh? Am I misinterpreting? The MAC is supposed to be world-wide
unique
to each interface. There are a couple of situations where this can
accidentally happen, like VMware using the same poorly-chosen random
MAC
for two VMs that breaks everything on that vSwitch, but that's the
only
one that I've ever encountered. Having the same MAC on two interfaces
is
not legal, so you should expect to break something on any router or
machine that I can think of. If it works, then that router is
broken.
Mac=Macintosh rather than MAC=Medium Access Control?
poc
5:50 p.m.
On 02Aug2021 09:04, John Mellor <john.mellor(a)gmail.com> wrote:
On 2021-08-01 7:08 p.m., Cameron Simpson wrote:
>We've got a few unmanaged netgear switches here and have had some
>weirdness ourselves. I have lossely discovered that having my Mac on
>both ethernet and wifi at once causes the LAN to go sour.
>. . .
Huh? Am I misinterpreting? The MAC is supposed to be world-wide
unique to each interface.
As I said, the actual meachanism is unverified. We have strong
circumstantial evidence that if my Mac has wifi on and I activate the
ethernet as well, sometimes the local LAN wigs out. There's no router
stuff here - access to other hosts on the same LAN stops working.
Unmanaged switches involved, and power cycling a switch has sometimes
brought order again.
I conjecture stuff like ARP requests getting answered from the wrong
interface, or something. I'd have to experiment with tcpdump some time.
I don't have the same MAC on two interfeaces, but other confusion may
abound. I know the firewall complains constantly about this:
arp info overwritten for 172.16.3.17 by 00:f7:6f:d5:2d:d4 on vr2
arp info overwritten for 172.16.3.17 by 68:d9:3c:8a:bd:dd on vr2
I'm actually unsure what's using that address :-(
Cheers,
Cameron Simpson <cs(a)cskk.id.au>
12:29 a.m.
On 03Aug2021 08:50, Cameron Simpson <cs(a)cskk.id.au> wrote:
I know the firewall complains constantly about this:
arp info overwritten for 172.16.3.17 by 00:f7:6f:d5:2d:d4 on vr2
arp info overwritten for 172.16.3.17 by 68:d9:3c:8a:bd:dd on vr2
It's the Apple TV. It has both wifi and ethernet and the same static
address for each. Normal, like Samuel's setup.
Cheers,
Cameron Simpson <cs(a)cskk.id.au>
8:17 a.m.
On 2021-08-02 6:50 p.m., Cameron Simpson wrote:
On 02Aug2021 09:04, John Mellor <john.mellor(a)gmail.com> wrote:
> On 2021-08-01 7:08 p.m., Cameron Simpson wrote:
>> We've got a few unmanaged netgear switches here and have had some
>> weirdness ourselves. I have lossely discovered that having my Mac on
>> both ethernet and wifi at once causes the LAN to go sour.
>> . . .
> Huh? Am I misinterpreting? The MAC is supposed to be world-wide
> unique to each interface.
As I said, the actual meachanism is unverified. We have strong
circumstantial evidence that if my Mac has wifi on and I activate the
ethernet as well, sometimes the local LAN wigs out. There's no router
stuff here - access to other hosts on the same LAN stops working.
Unmanaged switches involved, and power cycling a switch has sometimes
brought order again.
I conjecture stuff like ARP requests getting answered from the wrong
interface, or something. I'd have to experiment with tcpdump some time.
I don't have the same MAC on two interfeaces, but other confusion may
abound. I know the firewall complains constantly about this:
arp info overwritten for 172.16.3.17 by 00:f7:6f:d5:2d:d4 on vr2
arp info overwritten for 172.16.3.17 by 68:d9:3c:8a:bd:dd on vr2
I'm actually unsure what's using that address :-(
The only interfaces that I'm aware of that did that were the E1000 chips
that Intel made. They would once in a long while use the MAC in some
ARP packet from another machine as their own, breaking routing for the
whole network. There was no fix short of replacing all your Intel
ethernet cards and/or machines, as the error is in hardware.
If your Apple is using a USB-connected ethernet, maybe it has the
totally broken Intel chip?
--
John Mellor
6:16 a.m.
On Mon, 2 Aug 2021 09:04:03 -0400
John Mellor <john.mellor(a)gmail.com> wrote:
On 2021-08-01 7:08 p.m., Cameron Simpson wrote:
> On 27Jul2021 15:22, Tom Horsley <horsley1953(a)gmail.com> wrote:
>> Never mind. I rebooted the router and it works now. I've noticed
>> a lot of weirdness with this router (Netgear Nighthawk RAX200)
>> and routing between wired and wireless devices on my local network.
>> You'd think a top of the line router could get that right :-(.
> We've got a few unmanaged netgear switches here and have had some
> weirdness ourselves. I have lossely discovered that having my Mac on
> both ethernet and wifi at once causes the LAN to go sour.
>
> . . .
Huh? Am I misinterpreting? The MAC is supposed to be world-wide unique to each
interface. There are a couple of situations where this can accidentally happen, like
VMware using the same poorly-chosen random MAC for two VMs that breaks everything on that
vSwitch, but that's the only one that I've ever encountered. Having the same MAC
on two interfaces is not legal, so you should expect to break something on any router or
machine that I can think of. If it works, then that router is broken.
--
John Mellor
_______________________________________________
Many years ago we have a problem with the Cisco gear.
Two of their boxes had a identical MAC.
The MAC is supposed to be world-wide unique to each interface. :-)
BR, Bob
990
days inactive
997
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14 comments
8 participants
participants (8)
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Bob Marcan -
Cameron Simpson -
George N. White III -
John Mellor -
Patrick O'Callaghan -
Samuel Sieb -
Tim -
Tom Horsley