Create and manage kernel layer-2 bridges with the iproute2 bridge tool to connect interfaces and virtual machines. 19.06.2026 | reading time: 2 min The `bridge` command from iproute2 configures kernel layer-2 bridges so that multiple interfaces behave like a single switch; this guide shows practical, repeatable steps to create a bridge, add interfaces and inspect forwarding behavior. Quick hands-on example Create a simple bridge, move a NIC into it and bring it up with these commands and check status: ```$ sudo ip link add name br0 type bridge; $ sudo ip link set dev eth1 master br0; $ sudo ip link set dev br0 up; $ sudo ip addr add 192.168.100.1/24 dev br0; $ ip -d link show br0``` The output will report br0 with state UP and list eth1 as a port, confirming the bridge is active. Beyond the basics Use `bridge` to inspect and tune forwarding with `bridge fdb show`, manage VLAN membership with `bridge vlan`, and control STP and ageing; combine with `ip link` to set MTU or promiscuous mode and with firewalling (ebtables or nftables bridge family) to filter at layer 2. Tools that complement bridging Although `bridge` is the modern tool, older systems still have `brctl`, and complex deployments often use Open vSwitch with `ovs-vsctl`; network managers and systemd-networkd can automate bridge creation during boot or by central configuration. Wrap-up and next steps Bridges glue interfaces into a virtual switch inside the kernel; he who practices creating, inspecting and VLAN-tagging bridges will quickly master common virtualization and container networking patterns, and pursuing further Linux certification such as CompTIA Linux+ or LPIC-1 with intensive exam preparation at bitsandbytes.academy is a practical next step. Join Bits & Bytes Academy First class LINUX exam preparation. network utilities virtualization infrastructure
