Lost internet connection within 1 hour after install

Verrain

New Member
Dec 1, 2022
14
1
3
Dear Proxmox Commuinity,

I'm new to proxmox. After install everything looks fine with my network settings, but I lost the internet connection within 1 hour after install. I've checked the /etc/network/interface and every thing looks fine.

It is interesting, that I can access the proxmoxVE-"server" due to another computer that is connected by a switch and stand next to the proxmoxVE furthermore. But each ping to local dns server or the google dns server 8.8.8.8 ends in lost packages.

After fresh install of Proxmox the internet connections works again for about 1hour. So I copied the syslog for you. Maybe you can help me, what happens within this hour.

Thank you very much!
Verrain

Code:
Dec 01 10:08:21 seo007 pvescheduler[1391]: starting server
Dec 01 10:08:21 seo007 systemd[1]: Started Proxmox VE scheduler.
Dec 01 10:08:25 seo007 chronyd[1155]: Selected source 62.149.0.30 (2.debian.pool.ntp.org)
Dec 01 10:08:25 seo007 chronyd[1155]: System clock TAI offset set to 37 seconds
Dec 01 10:08:26 seo007 smartd[1025]: Device: /dev/sdb [SAT], SMART Usage Attribute: 190 Airflow_Temperature_Cel changed from 66 to 65
Dec 01 10:08:26 seo007 smartd[1025]: Device: /dev/sdb [SAT], SMART Usage Attribute: 194 Temperature_Celsius changed from 34 to 35
Dec 01 10:08:31 seo007 smartd[1025]: Device: /dev/sdc [SAT], SMART Usage Attribute: 190 Airflow_Temperature_Cel changed from 64 to 63
Dec 01 10:08:31 seo007 smartd[1025]: Device: /dev/sdc [SAT], SMART Usage Attribute: 194 Temperature_Celsius changed from 36 to 37
Dec 01 10:08:37 seo007 smartd[1025]: Device: /dev/sda [SAT], state written to /var/lib/smartmontools/smartd.ST4000NM000A_2HZ100-WS23TELB.ata.state
Dec 01 10:08:37 seo007 smartd[1025]: Device: /dev/sdb [SAT], state written to /var/lib/smartmontools/smartd.ST4000NM000A_2HZ100-WS23SVDF.ata.state
Dec 01 10:08:37 seo007 smartd[1025]: Device: /dev/sdc [SAT], state written to /var/lib/smartmontools/smartd.ST4000NM000A_2HZ100-WS22MA5E.ata.state
Dec 01 10:08:37 seo007 smartd[1025]: Device: /dev/sdd [SAT], state written to /var/lib/smartmontools/smartd.ST4000NM000A_2HZ100-WS22MK4N.ata.state
Dec 01 10:08:37 seo007 smartd[1025]: Device: /dev/nvme0, state written to /var/lib/smartmontools/smartd.WDC_PC_SN730_SDBPNTY_1T00_1016-21415X800114.nvme.state
Dec 01 10:08:37 seo007 systemd[1]: Started Self Monitoring and Reporting Technology (SMART) Daemon.
Dec 01 10:08:37 seo007 systemd[1]: Reached target Multi-User System.
Dec 01 10:08:37 seo007 systemd[1]: Reached target Graphical Interface.
Dec 01 10:08:37 seo007 systemd[1]: Starting Update UTMP about System Runlevel Changes...
Dec 01 10:08:37 seo007 systemd[1]: systemd-update-utmp-runlevel.service: Succeeded.
Dec 01 10:08:37 seo007 systemd[1]: Finished Update UTMP about System Runlevel Changes.
Dec 01 10:08:37 seo007 systemd[1]: Startup finished in 18min 52.125s (firmware) + 6.714s (loader) + 4.507s (kernel) + 23.230s (userspace) = 19min 26.578s.
Dec 01 10:08:44 seo007 systemd[1]: systemd-fsckd.service: Succeeded.
Dec 01 10:09:05 seo007 pvedaemon[1372]: <root@pam> successful auth for user 'root@pam'
Dec 01 10:09:05 seo007 pvedaemon[1370]: update new package list: /var/lib/pve-manager/pkgupdates
Dec 01 10:09:15 seo007 pvedaemon[1526]: starting termproxy UPID:seo007:000005F6:000019A4:63886F3B:vncshell::root@pam:
Dec 01 10:09:15 seo007 pvedaemon[1371]: <root@pam> starting task UPID:seo007:000005F6:000019A4:63886F3B:vncshell::root@pam:
Dec 01 10:09:15 seo007 pvedaemon[1372]: <root@pam> successful auth for user 'root@pam'
Dec 01 10:09:15 seo007 login[1533]: pam_unix(login:session): session opened for user root(uid=0) by (uid=0)
Dec 01 10:09:15 seo007 systemd[1]: Created slice User Slice of UID 0.
Dec 01 10:09:15 seo007 systemd[1]: Starting User Runtime Directory /run/user/0...
Dec 01 10:09:15 seo007 systemd-logind[1036]: New session 1 of user root.
Dec 01 10:09:15 seo007 systemd[1]: Finished User Runtime Directory /run/user/0.
Dec 01 10:09:15 seo007 systemd[1]: Starting User Manager for UID 0...
Dec 01 10:09:15 seo007 systemd[1539]: pam_unix(systemd-user:session): session opened for user root(uid=0) by (uid=0)
Dec 01 10:09:15 seo007 systemd[1539]: Queued start job for default target Main User Target.
Dec 01 10:09:15 seo007 systemd[1539]: Created slice User Application Slice.
Dec 01 10:09:15 seo007 systemd[1539]: Reached target Paths.
Dec 01 10:09:15 seo007 systemd[1539]: Reached target Timers.
Dec 01 10:09:15 seo007 systemd[1539]: Listening on GnuPG network certificate management daemon.
Dec 01 10:09:15 seo007 systemd[1539]: Listening on GnuPG cryptographic agent and passphrase cache (access for web browsers).
Dec 01 10:09:15 seo007 systemd[1539]: Listening on GnuPG cryptographic agent and passphrase cache (restricted).
Dec 01 10:09:15 seo007 systemd[1539]: Listening on GnuPG cryptographic agent (ssh-agent emulation).
Dec 01 10:09:15 seo007 systemd[1539]: Listening on GnuPG cryptographic agent and passphrase cache.
Dec 01 10:09:15 seo007 systemd[1539]: Reached target Sockets.
Dec 01 10:09:15 seo007 systemd[1539]: Reached target Basic System.
Dec 01 10:09:15 seo007 systemd[1539]: Reached target Main User Target.
Dec 01 10:09:15 seo007 systemd[1539]: Startup finished in 73ms.
Dec 01 10:09:15 seo007 systemd[1]: Started User Manager for UID 0.
Dec 01 10:09:15 seo007 systemd[1]: Started Session 1 of user root.
Dec 01 10:09:15 seo007 login[1553]: ROOT LOGIN  on '/dev/pts/0'
Dec 01 10:17:01 seo007 CRON[3950]: pam_unix(cron:session): session opened for user root(uid=0) by (uid=0)
Dec 01 10:17:01 seo007 CRON[3951]: (root) CMD (   cd / && run-parts --report /etc/cron.hourly)
Dec 01 10:17:01 seo007 CRON[3950]: pam_unix(cron:session): session closed for user root
Dec 01 10:23:17 seo007 systemd[1]: Starting Cleanup of Temporary Directories...
Dec 01 10:23:17 seo007 systemd[1]: systemd-tmpfiles-clean.service: Succeeded.
Dec 01 10:23:17 seo007 systemd[1]: Finished Cleanup of Temporary Directories.
Dec 01 10:24:05 seo007 pvedaemon[1372]: <root@pam> successful auth for user 'root@pam'
Dec 01 10:34:00 seo007 pveproxy[1378]: worker 1381 finished
Dec 01 10:34:00 seo007 pveproxy[1378]: starting 1 worker(s)
Dec 01 10:34:00 seo007 pveproxy[1378]: worker 8939 started
Dec 01 10:34:04 seo007 pveproxy[8934]: got inotify poll request in wrong process - disabling inotify
Dec 01 10:38:47 seo007 smartd[1025]: Device: /dev/sdb [SAT], SMART Usage Attribute: 190 Airflow_Temperature_Cel changed from 65 to 66
Dec 01 10:38:47 seo007 smartd[1025]: Device: /dev/sdb [SAT], SMART Usage Attribute: 194 Temperature_Celsius changed from 35 to 34
Dec 01 10:38:52 seo007 smartd[1025]: Device: /dev/sdc [SAT], SMART Usage Attribute: 190 Airflow_Temperature_Cel changed from 63 to 64
Dec 01 10:38:52 seo007 smartd[1025]: Device: /dev/sdc [SAT], SMART Usage Attribute: 194 Temperature_Celsius changed from 37 to 36
Dec 01 10:39:06 seo007 pvedaemon[1372]: <root@pam> successful auth for user 'root@pam'
Dec 01 10:43:56 seo007 pveproxy[1380]: worker exit
Dec 01 10:43:56 seo007 pveproxy[1378]: worker 1380 finished
Dec 01 10:43:56 seo007 pveproxy[1378]: starting 1 worker(s)
Dec 01 10:43:56 seo007 pveproxy[1378]: worker 11825 started
Dec 01 10:45:43 seo007 pveproxy[1379]: worker exit
Dec 01 10:45:43 seo007 pveproxy[1378]: worker 1379 finished
Dec 01 10:45:43 seo007 pveproxy[1378]: starting 1 worker(s)
Dec 01 10:45:43 seo007 pveproxy[1378]: worker 12387 started
Dec 01 10:54:06 seo007 pvedaemon[1372]: <root@pam> successful auth for user 'root@pam'
Dec 01 10:57:54 seo007 pvedaemon[1372]: worker exit
Dec 01 10:57:54 seo007 pvedaemon[1369]: worker 1372 finished
Dec 01 10:57:54 seo007 pvedaemon[1369]: starting 1 worker(s)
Dec 01 10:57:54 seo007 pvedaemon[1369]: worker 16022 started
Dec 01 11:06:23 seo007 pvedaemon[1370]: worker exit
Dec 01 11:06:23 seo007 pvedaemon[1369]: worker 1370 finished
Dec 01 11:06:23 seo007 pvedaemon[1369]: starting 1 worker(s)
Dec 01 11:06:23 seo007 pvedaemon[1369]: worker 18547 started
Dec 01 11:09:07 seo007 pvedaemon[1371]: <root@pam> successful auth for user 'root@pam'
Dec 01 11:10:32 seo007 pvedaemon[1371]: worker exit
Dec 01 11:10:32 seo007 pvedaemon[1369]: worker 1371 finished
Dec 01 11:10:32 seo007 pvedaemon[1369]: starting 1 worker(s)
Dec 01 11:10:32 seo007 pvedaemon[1369]: worker 19734 started
Dec 01 11:12:24 seo007 pveproxy[8939]: worker exit
Dec 01 11:12:24 seo007 pveproxy[1378]: worker 8939 finished
Dec 01 11:12:24 seo007 pveproxy[1378]: starting 1 worker(s)
Dec 01 11:12:24 seo007 pveproxy[1378]: worker 20268 started
Dec 01 11:17:01 seo007 CRON[21539]: pam_unix(cron:session): session opened for user root(uid=0) by (uid=0)
Dec 01 11:17:01 seo007 CRON[21540]: (root) CMD (   cd / && run-parts --report /etc/cron.hourly)
Dec 01 11:17:01 seo007 CRON[21539]: pam_unix(cron:session): session closed for user root
Dec 01 11:24:08 seo007 pvedaemon[16022]: <root@pam> successful auth for user 'root@pam'
Dec 01 11:27:07 seo007 pveproxy[1378]: worker 12387 finished
Dec 01 11:27:07 seo007 pveproxy[1378]: starting 1 worker(s)
Dec 01 11:27:07 seo007 pveproxy[1378]: worker 24249 started
Dec 01 11:27:08 seo007 pveproxy[24246]: got inotify poll request in wrong process - disabling inotify
Dec 01 11:27:08 seo007 pveproxy[24246]: worker exit
Dec 01 11:29:15 seo007 pveproxy[11825]: worker exit
Dec 01 11:29:15 seo007 pveproxy[1378]: worker 11825 finished
Dec 01 11:29:15 seo007 pveproxy[1378]: starting 1 worker(s)
Dec 01 11:29:15 seo007 pveproxy[1378]: worker 24871 started
Dec 01 11:39:08 seo007 pvedaemon[16022]: <root@pam> successful auth for user 'root@pam'
Dec 01 11:41:34 seo007 pvedaemon[28105]: starting termproxy UPID:seo007:00006DC9:00088D93:638884DE:vncshell::root@pam:
Dec 01 11:41:34 seo007 pvedaemon[16022]: <root@pam> starting task UPID:seo007:00006DC9:00088D93:638884DE:vncshell::root@pam:
Dec 01 11:41:34 seo007 pvedaemon[18547]: <root@pam> successful auth for user 'root@pam'
Dec 01 11:41:47 seo007 pvedaemon[16022]: <root@pam> end task UPID:seo007:00006DC9:00088D93:638884DE:vncshell::root@pam: OK
Dec 01 11:41:50 seo007 pvedaemon[16022]: <root@pam> starting task UPID:seo007:00006E00:000893A9:638884EE:aptupdate::root@pam:
Dec 01 11:42:00 seo007 pvedaemon[28160]: command 'apt-get update' failed: received interrupt
Dec 01 11:42:00 seo007 pvedaemon[16022]: <root@pam> end task UPID:seo007:00006E00:000893A9:638884EE:aptupdate::root@pam: command 'apt-get update' failed: received interrupt
Dec 01 11:53:59 seo007 pveproxy[20268]: worker exit
Dec 01 11:53:59 seo007 pveproxy[1378]: worker 20268 finished
Dec 01 11:53:59 seo007 pveproxy[1378]: starting 1 worker(s)
Dec 01 11:53:59 seo007 pveproxy[1378]: worker 31175 started
Dec 01 11:54:09 seo007 pvedaemon[16022]: <root@pam> successful auth for user 'root@pam'
Dec 01 11:56:02 seo007 pvedaemon[16022]: worker exit
Dec 01 11:56:02 seo007 pvedaemon[1369]: worker 16022 finished
Dec 01 11:56:02 seo007 pvedaemon[1369]: starting 1 worker(s)
Dec 01 11:56:02 seo007 pvedaemon[1369]: worker 31775 started
 
Last edited:
Please provide the output of pveversion -v, cat /etc/network/interfaces, cat /etc/pve/firewall/cluster.fw and cat /etc/pve/firewall/host.fw
 
pveversion -v
Code:
root@seo007:~# pveversion -v
proxmox-ve: 7.3-1 (running kernel: 5.15.74-1-pve)
pve-manager: 7.3-3 (running version: 7.3-3/c3928077)
pve-kernel-5.15: 7.2-14
pve-kernel-helper: 7.2-14
pve-kernel-5.15.74-1-pve: 5.15.74-1
pve-kernel-5.15.30-2-pve: 5.15.30-3
ceph-fuse: 15.2.16-pve1
corosync: 3.1.7-pve1
criu: 3.15-1+pve-1
glusterfs-client: 9.2-1
ifupdown2: 3.1.0-1+pmx3
ksm-control-daemon: 1.4-1
libjs-extjs: 7.0.0-1
libknet1: 1.24-pve2
libproxmox-acme-perl: 1.4.2
libproxmox-backup-qemu0: 1.3.1-1
libpve-access-control: 7.2-5
libpve-apiclient-perl: 3.2-1
libpve-common-perl: 7.3-1
libpve-guest-common-perl: 4.2-3
libpve-http-server-perl: 4.1-5
libpve-storage-perl: 7.3-1
libspice-server1: 0.14.3-2.1
lvm2: 2.03.11-2.1
lxc-pve: 5.0.0-3
lxcfs: 4.0.12-pve1
novnc-pve: 1.3.0-3
proxmox-backup-client: 2.3.1-1
proxmox-backup-file-restore: 2.3.1-1
proxmox-mini-journalreader: 1.3-1
proxmox-offline-mirror-helper: 0.5.0-1
proxmox-widget-toolkit: 3.5.3
pve-cluster: 7.3-1
pve-container: 4.4-2
pve-docs: 7.3-1
pve-edk2-firmware: 3.20220526-1
pve-firewall: 4.2-7
pve-firmware: 3.5-6
pve-ha-manager: 3.5.1
pve-i18n: 2.8-1
pve-qemu-kvm: 7.1.0-4
pve-xtermjs: 4.16.0-1
qemu-server: 7.3-1
smartmontools: 7.2-pve3
spiceterm: 3.2-2
swtpm: 0.8.0~bpo11+2
vncterm: 1.7-1
zfsutils-linux: 2.1.6-pve1

interface
Code:
root@seo007:~# cat /etc/network/interfaces
auto lo
iface lo inet loopback

iface eno2 inet manual

auto vmbr0
iface vmbr0 inet static
        address 172.26.28.60/22
        hwaddress 68:84:7e:79:fb:7f
        gateway 172.26.31.254
        bridge-ports eno2
        bridge-stp off
        bridge-fd 0

iface eno1 inet manual

I didn't setup a Firewall until now:
Code:
root@seo007:~# cat /etc/pve/firewall/cluster.fw
cat: /etc/pve/firewall/cluster.fw: No such file or directory
root@seo007:~# cat /etc/pve/firewall/host.fw
cat: /etc/pve/firewall/host.fw: No such file or directory

I have to say, that the workstation ist connected to the network of a university. But I can make entries on the DHCP-Server by myself and registered both networkcards. How I wrote, after installation, everything is fine, so I think the network settings (Gateway, DNS-Server, etc.) are correctly.

Regards and much thanks for your advice!
Verrain
 
Last edited:
Can you still ping the gateway once you lose connection to the outside?
If so, the issue might be on the gateway or somewhere else in the network.
 
No I can't even ping the gateway anymore after the network connection is lost :/
 
Last edited:
I have checked the exaxt moment of connection lost, but at this moment nothing appears as new in the syslog. The first entrance after that is (few minutes later):
Code:
Dec 07 16:29:31 seo007 pveproxy[7892]: worker exit
Dec 07 16:29:31 seo007 pveproxy[1405]: worker 7892 finished
Dec 07 16:29:31 seo007 pveproxy[1405]: starting 1 worker(s)
Dec 07 16:29:31 seo007 pveproxy[1405]: worker 18519 started
 
What I could think of in this case is either a duplicate IP or a duplicate MAC address in the network.
Have you checked for this?
 
I solved the problem in an acceptable way:

I setup the google dns server as a second dnsserver in
/etc/resolv.conv

by adding the line
nameserver 8.8.8.8

After that the network connection works fine again.

So it must have something to do with the dns server of the university, that doesn't connect me anymore.

Regards
Ricardo Rose

edit: Now I've lost the connection again... But I've seen, that the dhcp server have a lease time of 1h. I think that could be the problem and I will ask our computer center...
 
Last edited:
What I could think of in this case is either a duplicate IP or a duplicate MAC address in the network.
Have you checked for this?

The Bridge have the same IP and the same MAC (see upside in the posted interface) as the real Networkinterface eno2. Can this cause a problem with doubled IPs?
 
Last edited:
Okay, I recogonise, that the problem has definitely something to do with the DHCP Server. The computer centre of the university said, that the handshake between my workstation and the DHCP server fails and when the lease time is over, my network connection is lost
.
 
Last edited:
This time I solved it really. The problem was this line in the interfaces file:
iface vmbr0 inet static

It has to be set from static to dhcp even the dhcp server gives me a static IP. That is a bit confusing to me, but at my normal office PC I also have not set a static ip. So it makes sense. Then I also applied another network configuration, to route all network traffic from the VMs through one real interface (I deactivated the second NIC, that was listed in the interfaces above). You can find the configuration here:
https://pve.proxmox.com/wiki/Network_Configuration

Code:
root@seo007:~# cat /etc/network/interfaces
auto lo
iface lo inet loopback

auto eno1
iface eno1 inet dhcp
        post-up echo 1 > /proc/sys/net/ipv4/ip_forward
        post-up echo 1 > /proc/sys/net/ipv4/conf/eno1/proxy_arp


auto vmbr0
iface vmbr0 inet static
        address  10.10.10.1/28
        bridge-ports none
        bridge-stp off
        bridge-fd 0

Be aware of that this to system variables has to be set (you can find how to do that in the internet):
ip_forward = 1
proxy_arp = 1

So we have the "real" NIC eno1 that get his IP from the DHCP server of the university and we have the bridge, that act as a virtual switch for the VMs.

Best regards
Verrain
 
Last edited:
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