bridge
Create and manage network bridge devices
TLDR
List all bridges and their interfaces
Show port vlan information
Assign a VLAN to a port
Remove a VLAN from a port
Watch for changes in bridge interfaces
Display help
SYNOPSIS
bridge [OPTIONS] OBJECT { COMMAND | help }
PARAMETERS
-V, --version
Print version and exit.
-s, --statistics
Output more statistics.
-d, --details
Show detailed information.
-t, --timestamp
Print timestamps.
-n, --no-nl-pid
Disable netlink PID reporting.
-c, --config
Use config mode (experimental).
-a, --all
Dump information on all objects.
-f, --force
Force execution.
-4, --ipv4
IPv4 addresses only.
-6, --ipv6
IPv6 addresses only.
-F, --fid-netlink
Use FID netlink protocol.
-j[key], --json[=key]
JSON output format.
FILE
Read from configuration file.
DESCRIPTION
The bridge command from the iproute2 suite configures and queries Ethernet bridge devices in the Linux kernel. It handles bridge ports (links), forwarding database (fdb), multicast database (mdb), VLAN filtering, and monitoring. This tool enables creation of virtual layer-2 switches by bridging interfaces, supporting features like Spanning Tree Protocol (STP) options, MAC learning control, flooding, proxy ARP, multicast handling, VLAN tunneling, port isolation, and backlog queues.
Used in virtualization (e.g., KVM, containers), SDN setups, or multi-homed servers, it communicates via netlink for efficient kernel interaction. Output can be in JSON for automation. It largely replaces the older brctl tool, offering more options and better performance.
Requires kernel bridge module loaded (CONFIG_BRIDGE). Common tasks include adding/removing ports, setting costs/priorities, enabling fast-leave for IGMP/MLD, or dumping FDB entries for debugging.
CAVEATS
Requires root privileges or CAP_NET_ADMIN.
Feature availability depends on kernel config (e.g., CONFIG_BRIDGE_VLAN_FILTERING).
Some options experimental or kernel-version specific.
MAIN OBJECTS
link: port management.
fdb: MAC forwarding DB.
mdb: multicast group DB.
vlan: VLAN filtering.
monitor: all events.
EXAMPLES
bridge link show
bridge fdb show
bridge vlan add dev eth1 vid 100 pvid untagged
bridge link set dev eth0 master br0 cost 100 learning off
HISTORY
Added to iproute2 in version 3.16 (2014) for netlink-based bridge control, evolving from ioctl-based brctl (bridge-utils, 2000s). Fully integrated by iproute2 5.x with VLAN/MDB support matching kernel 4.x+ advancements.
