Paweł Szaga home page
How to permit traffic from KVM guest to KVM host with firewalld, for instance to access HTTP server running on KVM host form guest VMs. #permit traffic on firewall firewall-cmd --add-service=http --zone=libvirt firewall-cmd --add-service=http --zone=libvirt --permanent #verify firewall-cmd --list-all-zones
After upgrading Docker to version 20.10 on CentOS 8 and Fedora 33 we can see that it fails to start docker.service. In docker.service logs and firewalld.service logs we can see following message: ERROR: ZONE_CONFLICT: 'docker0' already bound to a zone Solution for this issue: sudo firewall-cmd --zone=trusted --remove-interface=docker0 sudo firewall-cmd --zone=trusted --remove-interface=docker0 --permanent
In Fedora 33 there is a systemd-resolved service enabled by default. Use following steps to make DSN working after establishing FortiSSL VPN connection using Network Manager (using NetworkManager-fortisslvpn-gnome plugin). Assuming that "ppp0" is you virtual network interface for VPN connection, you can set X.X.X.X and Y.Y.Y.Y as DNS servers: resolvectl dns ppp0 X.X.X.X Y.Y.Y.Y Add… Continue reading Fedora 33 - make DNS (systemd-resolved) working with NetworkManager's ForitSSL VPN connections
To work with kernel network namespaces created by Docker create necessary symbolic link: ln -s /var/run/docker/netns /var/run/netns List network namespaces: ip netns list Result will be similar to: # ip netns list 644c14147ad2 (id: 2) bb230cf5f65f (id: 1) e2772d19bfd0 (id: 0) Execute command inside network namespace: ip netns exec <namespace> <command> Example - listing network… Continue reading Working with kernel network namespaces created by Docker
Various useful commands for OpenWRT/LEDE devices: Show ethernet switch information: swconfig list swconfig dev switch0 show Updating packages: opkg update opkg list-upgradable opkg list-upgradable | awk '{ print $1 }' | xargs opkg upgrade Installing OpenVPN (with Easy-RSA) software: opkg install openvpn-openssl opkg install openvpn-easy-rsa Installing DynamicDNS client (with HTTPS nad LuCI support): opkg install… Continue reading OpenWRT - various useful commands