Always set keepalive less than firewall timeout with intvl and probes tuned for your use case
Archive for the ‘Linux Solution’ Category
TCP Keepalive is a standard OS level mechanism for detecting dead connections by periodically sending probe packets on idle TCP connections – both Windows and Linux default to 2 hours (7.200 seconds) before sending the first keepalive probe
Freitag, September 19th, 2025Linux Parameter ‚tcp_keepalive_time‘ – sets the idle time (in seconds) a TCP connection must remain inactive before the kernel starts sending keepalive probes to check if the other end is still responsive and the default value is 7.200 seconds (2 hours)
Mittwoch, September 17th, 2025The tcp_keepalive_time is part of a three-parameter system:
tcp_keepalive_time – the initial idle time before the first probe is sent (default: 7.200 seconds)
tcp_keepalive_intvl – the interval (in seconds) between subsequent keepalive probes if the previous one doesn’t receive an acknowledgment (default: 75 seconds)
tcp_keepalive_probes – the number of failed probes after which the connection is considered broken and is closed (default: 9)
root@pve-ubuntu-01:~# sysctl net.ipv4.tcp_keepalive_time net.ipv4.tcp_keepalive_intvl net.ipv4.tcp_keepalive_probes
net.ipv4.tcp_keepalive_time = 7200
net.ipv4.tcp_keepalive_intvl = 75
net.ipv4.tcp_keepalive_probes = 9
root@pve-ubuntu-01:~#
Change temporarily for testing:
root@pve-ubuntu-01:~# sysctl -w net.ipv4.tcp_keepalive_time=900 # Sets the time to 15 minutes
root@pve-ubuntu-01:~# sysctl -a | grep keep
net.ipv4.tcp_keepalive_intvl = 75
net.ipv4.tcp_keepalive_probes = 9
net.ipv4.tcp_keepalive_time = 900
net.ipv6.conf.all.keep_addr_on_down = 0
net.ipv6.conf.default.keep_addr_on_down = 0
net.ipv6.conf.eth0.keep_addr_on_down = 0
net.ipv6.conf.lo.keep_addr_on_down = 0
Always set keepalive less than firewall timeout with intvl and probes tuned for your use case
Proxmox Datacenter Manager (PDM) 0.9 Beta 1 – introduces a central interface for managing Proxmox Virtual Environment (VE) nodes and clusters
Dienstag, September 16th, 2025
Proxmox Datacenter Manager (PDM) – Roadmap
You can use the official ISO image to install Proxmox Datacenter Manager (PDM) on a virtual machine or bare metal host
Home Assistant – Anker SOLIX Solarbank 2 AC & Anker Smart Meter endlich einbinden
Sonntag, September 14th, 2025Bastion Host JumpServer v4.0 – is an open source PAM tool that provides efficient and secure asset management and operation auditing capabilities
Samstag, September 13th, 2025
JumpServer – is an open source Privileged Access Management (PAM) platform that provides DevOps and IT teams with on demand and secure access to SSH RDP Kubernetes Database and RemoteApp endpoints through a web browser
Proxmox Virtual Environment (VE) 9.0.6 – how to remove a directory entry e.g. ‚BackupUSB‘
Samstag, September 13th, 2025
# grep -R -i /mnt/pve/BackupUSB /etc/
/etc/systemd/system/mnt-pve-BackupUSB.mount:Where=/mnt/pve/BackupUSB
/etc/systemd/system/multi-user.target.wants/mnt-pve-BackupUSB.mount:Where=/mnt/pve/BackupUSB
grep: /etc/systemd/system/multi-user.target.wants/mnt-pve-Backup\x2dpve\x2ds740\x2d04.mount: No such file or directory
/etc/mtab:/dev/sdc1 /mnt/pve/BackupUSB ext4 rw,relatime 0 0
/etc/pve/storage.cfg: path /mnt/pve/BackupUSB
# systemctl disable mnt-pve-BackupUSB.mount
# umount /mnt/pve/BackupUSB
# vi /proc/mounts
/dev/sdc1 /mnt/pve/BackupUSB ext4 rw,relatime 0 0
# rm /etc/systemd/system/mnt-pve-BackupUSB.mount
You have to also remove the „dir: BackupUSB“ section from /etc/pve/storage.cfg
# vi /etc/pve/storage.cfg
…
dir: BackupUSB
path /mnt/pve/BackupUSB
content images,rootdir,snippets,backup,iso,vztmpl
is_mountpoint 1
nodes pve-s740-04
Traefik – the cloud native application proxy
Samstag, September 13th, 2025Günstige vServer von allen Hostern z.B.: netcup VPS nano G11s – kommen wir zu den Tests
Freitag, September 12th, 2025Docker Setup – simple clean and easy to backup
Freitag, September 12th, 2025Thomas-Krenn.AG – OPNsense für Anwender
Donnerstag, September 11th, 2025Linux Tipp #10 – Dateioperationen
Donnerstag, September 11th, 2025Raspberry Pi 1 Model B (hergestellt in 2012) – upgrade to Syncthing v2.x
Samstag, September 6th, 2025
Syncthing Repository for apt-get
https://apt.syncthing.net/
root@rpi-iot-jsho-syncthing-01:~#
root@rpi-iot-jsho-syncthing-01:~# echo „deb [signed-by=/etc/apt/keyrings/syncthing-archive-keyring.gpg] https://apt.syncthing.net/ syncthing stable-v2“ | tee /etc/apt/sources.list.d/syncthing.list
root@rpi-iot-jsho-syncthing-01:~#
root@rpi-iot-jsho-syncthing-01:~# apt-get update -y
root@rpi-iot-jsho-syncthing-01:~# apt-get upgrade -y
