Bridging

Overview

  • Bridging creates a virtual switch

  • A bridge can handle STP (be aware of it!)

  • Usually the bridge uses a physical interface like eth0 as uplink

Setup

  • Install bridge-utils

  • Add a new bridge interface

brctl addbr br0

  • Add uplink

brctl addif br0 eth0

  • Add other ports

  • Show config

brctl show

  • Remember to disable STP if you dont need it!

brctl stp br0 off

  • Switch of network-manager

  • Here how a bridge can be automatically configured with RHEL/CentOS/Fedora

DEVICE=br0
TYPE=Bridge
ONBOOT=yes
DELAY=0
BOOTPROTO=static
IPADDR=192.168.100.1
NETMASK=255.255.255.0
STP=off

  • And how to add eth0 as uplink

BRIDGE=br0
NM_CONTROLLED=no

Firewalling

  • To disable firewalling between bridge ports check /proc/sys/net/bridge/bridge-nf-call-*