Lost internet access on Trixie this morning.

Discussion:

(too old to reply)

Frank McCormick

2024-09-16 18:10:01 UTC

I am faced with a strange problem. I have no internet access on Trixie
on one of two partitions on my ssd.
I was attempting to solve a problem I am having with Vivaldi by
installing Seahorse. Apt quit halfway through downloading the necessary
files complaining it could not resolve a bunch of Debian repositories.
Ever since that I have no internet access in Trixie. It's not a hardware
problem as I have full access on the other partition which runs Opensuse
Tumbleweed. Earlier today I did an update of Trixie and it went fine.

Can someone help me diagnose the problem ?

This is my apt sources list

deb http://deb.debian.org/debian trixie main contrib non-free
non-free-firmware
deb-src http://deb.debian.org/debian trixie main contrib non-free
deb http://deb.debian.org/debian trixie-updates main contrib non-free
non-free-firmware
deb-src http://deb.debian.org/debian trixie-updates main contrib non-free

deb http://deb.debian.org/debian trixie-backports main contrib non-free
non-free-firmware
deb-src http://deb.debian.org/debian trixie-backports main contrib non-free
deb http://deb.debian.org/debian trixie-proposed-updates
non-free-firmware main contrib non-free

Thanks

Kent West

2024-09-16 18:30:01 UTC

Permalink

What happens if you try:

# systemctl restart networking

I've had to do that several times today on my sid box. I've not gotten
around to pursuing the problem, as the above solves my problem (at least
temporarily).

--
Kent West <")))><
IT Support / Client Support
Abilene Christian University
Westing Peacefully - http://kentwest.blogspot.com

Frank McCormick

2024-09-16 18:50:01 UTC

Permalink

Post by Kent West

# systemctl restart networking
I've had to do that several times today on my sid box. I've not gotten
around to pursuing the problem, as the above solves my problem (at least
temporarily).

I'll reboot and try that. Following a suggestion I found on the net
I did sudo /etc/init.d/networking restart and that **seems** to have
restarted the network, BUT browsers can't find any sites and Thunderbird
reports failures to connect. I think I am over my head here but could it
be a DNS problem ??

Michael Kjörling

2024-09-16 19:20:01 UTC

Permalink

Post by Kent West
# systemctl restart networking

I'll reboot and try that. Following a suggestion I found on the net I did
sudo /etc/init.d/networking restart and that **seems** to have restarted the
network, BUT browsers can't find any sites and Thunderbird reports failures
to connect. I think I am over my head here but could it be a DNS problem ??

That certainly seems plausible.

Check your /etc/resolv.conf. Is it there? Is it sane? Also check
/etc/nsswitch.conf, particularly the hosts: entry.

The old-style sysvinit /etc/init.d scripts should be just wrappers
around the corresponding systemctl commands if you are running
systemd, which you almost certainly do unless you've gone out of your
way to do otherwise.

Confirm that you have IP (assuming IPv4 here; adjust as necessary if
you are in an IPv6-only world):

$ systemctl status networking
$ ip sh a
$ ip -N route
$ sudo traceroute -In 8.8.8.8
$ host www.example.com

(That last will likely fail to return anything useful if you have IP
but not DNS, possibly as a result of a DHCP failure or a broken
/etc/resolv.conf. A traceroute to Google's multicast public DNS
resolver should get you _something_ out of your local network. -I is
use ICMP which requires elevated privileges, hence sudo.)

Particularly, look for your network interface having an IP address on
the expected subnet from `ip sh a`, and look for a meaningful
`default` route in the output of `ip -N route`. If you have an IP
address in the 169.254.x.x range, then you have a DHCP issue.

You mention that you did a system upgrade earlier in the day, which
finished successfully. What exactly was updated then, and from what
and to what? The most recent apt log might very well be instructive.

--
Michael Kjörling 🔗 https://michael.kjorling.se
“Remember when, on the Internet, nobody cared that you were a dog?”

Dan Ritter

2024-09-16 18:40:02 UTC

Permalink

We can rule out the ISP, the router, any switches in the way,
any cables and the NIC because another OS works on the same
hardware.

What's left?

- firmware for the NIC loaded at boot time
- kernel recognition of the NIC
- IP address (via DHCP? static?)
- routing
- DNS

Testing some of these will rule out others if they succeed. Skip
to the ping check at the end, and if it doesn't work, let's go from the bottom up:

ip link show

If this gets you your NIC, then the firmware is OK and the
kernel recognizes it. Show us the output, please.

ip address show

If this gets you the correct (or a correct) IP address, then
DHCP or static address configuration is good. Again, show us the
output.

ping 8.8.8.8

If this gets through, then your machine can contact the
outside world. At that point, it's probably a DNS issue, and you
should report the contents of /etc/resolv.conf to us.

-dsr-

Frank McCormick

2024-09-16 19:20:01 UTC

Permalink

Post by Dan Ritter

Post by Frank McCormick
Ever since that I have no internet access in Trixie. It's not a hardware
problem as I have full access on the other partition which runs Opensuse
Tumbleweed. Earlier today I did an update of Trixie and it went fine.

We can rule out the ISP, the router, any switches in the way,
any cables and the NIC because another OS works on the same
hardware.
What's left?
- firmware for the NIC loaded at boot time
- kernel recognition of the NIC
- IP address (via DHCP? static?)
- routing
- DNS
Testing some of these will rule out others if they succeed. Skip
ip link show
If this gets you your NIC, then the firmware is OK and the
kernel recognizes it. Show us the output, please.
ip address show
If this gets you the correct (or a correct) IP address, then
DHCP or static address configuration is good. Again, show us the
output.
ping 8.8.8.8
If this gets through, then your machine can contact the
outside world. At that point, it's probably a DNS issue, and you
should report the contents of /etc/resolv.conf to us.

I'll reboot into Trixie and be back soon.
Thanks

Frank McCormick

2024-09-16 19:30:02 UTC

Permalink

It's not a hardware

Post by Dan Ritter

Post by Frank McCormick
problem as I have full access on the other partition which runs Opensuse
Tumbleweed. Earlier today I did an update of Trixie and it went fine.

franklin:/home/frank#
ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
mode DEFAULT group default qlen 1000 link/loopback 00:00:00:00:00:00
brd 00:00:00:00:00:00
2: eno1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode
DEFAULT group default qlen 1000
link/ether 44:87:fc:d8:3b:53 brd ff:ff:ff:ff:ff:ff
altname enp0s25
franklin:/home/frank#

ip address show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
group default qlen 1000 link/loopback 00:00:00:00:00:00 brd
00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft
forever
inet6 ::1/128 scope host noprefixroute
valid_lft forever preferred_lft forever
2: eno1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group
default qlen 1000
link/ether 44:87:fc:d8:3b:53 brd ff:ff:ff:ff:ff:ff altname enp0s25

ping: connect: Network is unreachable

franklin:/etc#
cat resolv.conf
# Generated by NetworkManager
nameserver 24.201.245.77
nameserver 24.200.243.189
nameserver 2607:fa48:2:f000::1 # NOTE: the libc resolver may not support
more than 3 nameservers.
# The nameservers listed below may not be recognized.
nameserver 2607:fa48:2:f008::1

I am no expert but it seems to look good. Firefox can't find any site,
Thunderbird still reports no connectionss.

Tom Furie

2024-09-16 19:40:01 UTC

Permalink

Post by Dan Ritter
ip address show
2: eno1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default
qlen 1000
link/ether 44:87:fc:d8:3b:53 brd ff:ff:ff:ff:ff:ff altname enp0s25
I am no expert but it seems to look good. Firefox can't find any site,
Thunderbird still reports no connectionss.

Actually, it doesn't look good - you don't have any ip addresses on eno1,
the interface is down. You're going to have to find out why that is.

Cheers,
Tom

--
Boucher's Observation:
He who blows his own horn always plays the music
several octaves higher than originally written.

Dan Ritter

2024-09-16 20:10:01 UTC

Permalink

Post by Tom Furie

Actually, it doesn't look good - you don't have any ip addresses on eno1,
the interface is down. You're going to have to find out why that is.

Since it's recognized, it was probably not configured.

Easiest: edit /etc/network/interfaces to include these lines for
eno1:

--
iface eno1 auto
iface eno1 inet dhcp
--

And then run

sudo ifup eno1

to get it running.

-dsr-

Greg Wooledge

2024-09-16 20:10:01 UTC

Permalink

Post by Dan Ritter

Post by Tom Furie
Actually, it doesn't look good - you don't have any ip addresses on eno1,
the interface is down. You're going to have to find out why that is.

Since it's recognized, it was probably not configured.
Easiest: edit /etc/network/interfaces to include these lines for
--
iface eno1 auto
iface eno1 inet dhcp
--
And then run
sudo ifup eno1
to get it running.

Didn't the initial message say that the Internet *was* working, and then
suddenly *stopped* working, right in the middle of a download?

That, together with the interface not being UP, points to the
configuration being OK, but something going wrong at the hardware or
kernel level, I think.

(Unless of course a configuration change was made during that download.)

Frank McCormick

2024-09-16 20:30:01 UTC

Permalink

Another user here made a comment that clued me into what the problem
really was. I had done an update of Trixie which went fine. Then I
started to do something which I had been planning for a while - remove
the Cinnamon desktop. I was doing it piecemeal when seemingly the
internet dropped out. It did, because part of the removal process at
that point was to remove network-manager. Long story shorter, I
downloaded network-manager and it's dependencies, copied them over to
Debian and installed them . The net popped up .

Sorry for the noise all caused by operator error. Thanks to all who
responded. If I had kept my eyes open to what I was doing, there would
not have been
a problem.

Post by Greg Wooledge

Post by Dan Ritter

Post by Tom Furie
Actually, it doesn't look good - you don't have any ip addresses on eno1,
the interface is down. You're going to have to find out why that is.

Didn't the initial message say that the Internet *was* working, and then
suddenly *stopped* working, right in the middle of a download?
That, together with the interface not being UP, points to the
configuration being OK, but something going wrong at the hardware or
kernel level, I think.
(Unless of course a configuration change was made during that download.)

--
Frank McCormick

Dan Ritter

2024-09-16 20:50:01 UTC

Permalink

Post by Greg Wooledge
Didn't the initial message say that the Internet *was* working, and then
suddenly *stopped* working, right in the middle of a download?
That, together with the interface not being UP, points to the
configuration being OK, but something going wrong at the hardware or
kernel level, I think.
(Unless of course a configuration change was made during that download.)

People sometimes say "download" when what they mean is "apt
upgrade which downloaded several packages".

-dsr-

Charles Curley

2024-09-16 20:30:01 UTC

Permalink

On Mon, 16 Sep 2024 15:24:22 -0400

Post by Dan Ritter
ip address show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
group default qlen 1000 link/loopback 00:00:00:00:00:00 brd
00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft
forever
inet6 ::1/128 scope host noprefixroute
valid_lft forever preferred_lft forever
2: eno1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group
default qlen 1000
link/ether 44:87:fc:d8:3b:53 brd ff:ff:ff:ff:ff:ff altname enp0s25

The interface at eno1 is DOWN. That's your problem; it either never got
initialized or went AWOL since.

For your education, here are three interfaces on one of my machines, two
initialized, the other not. This should give you an idea of what to
look for. lo you can ignore.

***@chaffee:~# ip ad
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: enp0s13: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
link/ether 00:01:c0:03:f8:44 brd ff:ff:ff:ff:ff:ff
inet 192.168.100.30/24 brd 192.168.100.255 scope global enp0s13
valid_lft forever preferred_lft forever
inet6 fe80::201:c0ff:fe03:f844/64 scope link
valid_lft forever preferred_lft forever
3: enp0s14: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether 00:01:c0:03:d3:b6 brd ff:ff:ff:ff:ff:ff
***@chaffee:~#

What you want to see is that UP in between the less than and greater
than signs. Note also the "state DOWN" for enp0s14, the same as your
eno1. enp0s13 is UP, and has an IPv4 address. It also has an IPv6, but
I don't use IPv6.

--
Does anybody read signatures any more?

https://charlescurley.com
https://charlescurley.com/blog/

t***@posteo.de

2024-09-16 18:50:01 UTC

Permalink

Post by Frank McCormick
I am faced with a strange problem. I have no internet access on Trixie
on one of two partitions on my ssd.
I was attempting to solve a problem I am having with Vivaldi by
installing Seahorse. Apt quit halfway through downloading the necessary
files complaining it could not resolve a bunch of Debian repositories.
Ever since that I have no internet access in Trixie. It's not a hardware
problem as I have full access on the other partition which runs Opensuse
Tumbleweed. Earlier today I did an update of Trixie and it went fine.
Can someone help me diagnose the problem ?
This is my apt sources list
deb http://deb.debian.org/debian trixie main contrib non-free
non-free-firmware
deb-src http://deb.debian.org/debian trixie main contrib non-free
deb http://deb.debian.org/debian trixie-updates main contrib non-free
non-free-firmware
deb-src http://deb.debian.org/debian trixie-updates main contrib non-free
deb http://deb.debian.org/debian trixie-backports main contrib non-free
non-free-firmware
deb-src http://deb.debian.org/debian trixie-backports main contrib non-free
deb http://deb.debian.org/debian trixie-proposed-updates
non-free-firmware main contrib non-free
Thanks

Hi!

I'm having similar random disconnect issues where even DHCP would stop working
since very recently.
Can you check if DHCP is broken for you too when this happens? Just pull the
reconnect ethernet and see if it's able to get an IP address at all.

Tuxifan

Frank McCormick

2024-09-16 19:40:01 UTC

Permalink

Post by t***@posteo.de

Post by Frank McCormick
I am faced with a strange problem. I have no internet access on Trixie
on one of two partitions on my ssd.

Hi!
I'm having similar random disconnect issues where even DHCP would stop working
since very recently.
Can you check if DHCP is broken for you too when this happens? Just pull the
reconnect ethernet and see if it's able to get an IP address at all.

I haven't had any DHCP problems at all. But I'll check.

Hans

2024-09-16 20:30:01 UTC

Permalink

What does

ifconfig -a

(eecute as root) tell?

Is it really enp0 or enp0s25?

--------------------

Second question:

If you give the network interface a hard ip, does it work?

In /etc/network/interfaces edit these lines like the example

------

auto lo enp0s10

iface lo inet loopback
address 127.0.0.1
netmask 255.0.0.0

iface enp0s10 inet static
address 192.168.3.2
netmask 255.255.255.0
broadcast 192.168.178.255
gateway 192.168.3.2

--------

Check the correct name of your ethernet device! See above.

--------------------

Also create (if not eistent) a file /etc/resolv.conf and enter DNS IPs like this example.

----
# Generated by NetworkManager
nameserver 208.67.222.222
nameserver 208.67.220.220
nameserver fd00::de39:6fff:fe2a:6101
# NOTE: the libc resolver may not support more than 3 nameservers.
# The nameservers listed below may not be recognized.
nameserver 2a02:560:58ad:b300:de39:6fff:fe2a:6101

-------

PLEASE NOTE: This is only for testing purposes! If you are using networ-manager, it will wuse
its own configuration files.

If this above is working, check, what is the difference to networ-manager.

If you now the ethernet device name (like enp0s10 in my eample), you can also try

dhclient enp0s10

as root. Of course you have to use the name of your ethernet device. (Besides, these names
are called "predicted names", but I think, you now this already).

Good luck!

Hans