Bridge
- networking/bridge
- 工作类似 Switch
- L2 learning and forwarding
- STP
- 让多路能正常工作
auto eth0
iface eth0 inet manual
auto br0
iface br0 inet dhcp
bridge-ports eth0
bridge-stp on
# 自定义 mac 确保 dhcp 稳定
# bridge-hw 00:00:00:00:00:00
# ip link set dev $IFACE type bridge ageing_time $IF_BRIDGE_AGEING
# brctl setageing
# ip link set dev $IFACE type bridge priority $IF_BRIDGE_BRIDGEPRIO
# brctl setbridgeprio
# ip link set dev $IFACE type bridge forward_delay $IF_BRIDGE_FD
# brctl setfd
# ip link set dev $IFACE type bridge hello_time $IF_BRIDGE_HELLO
# brctl sethello
# ip link set dev $IFACE type bridge max_age $IF_BRIDGE_MAXAGE
# brctl setmaxage
# bridge link set dev $IFACE cost $IF_BRIDGE_PATHCOST
# brctl setpathcost
# bridge link set dev $IFACE priority $IF_BRIDGE_PORTPRIO
# brctl setportprio
# ip link set dev $IFACE type bridge stp $(yesno $IF_BRIDGE_STP)
brctl stp br0 off
# vlan
# ip link set dev $IFACE type bridge vlan_filtering $(yesno $IF_BRIDGE_VLAN_AWARE)
#
brctl showmacs br0
brctl showstp br0
| brctl setATTR br val | for |
|---|---|
| setageing bridge time | Set ageing time |
| setbridgeprio bridge prio | Set bridge priority (between 0 and 65535) |
| setfd bridge time | Set bridge forward delay |
| sethello bridge time | Set hello time |
| setmaxage bridge time | Set max message age |
| setgcint bridge time | Set garbage collection interval in seconds |
| sethashel bridge int | Set hash elasticity |
| sethashmax bridge int | Set hash max |
| setmclmc bridge int | Set multicast last member count |
| setmcrouter bridge int | Set multicast router |
| setmcsnoop bridge int | Set multicast snooping |
| setmcsqc bridge int | Set multicast startup query count |
| setmclmi bridge time | Set multicast last member interval |
| setmcmi bridge time | Set multicast membership interval |
| setmcqpi bridge time | Set multicast querier interval |
| setmcqi bridge time | Set multicast query interval |
| setmcqri bridge time | Set multicast query response interval |
| setmcqri bridge time | Set multicast startup query interval |
| setpathcost bridge port cost | Set path cost |
| setportprio bridge port prio | Set port priority (between 0 and 255) |
| setportmcrouter bridge port int | Set port multicast router |
| sethashel bridge int | Set hash elasticity value |
bridge
- bridge.8
- fdb - Forwarding Database
- mdb - Multicast group database
- BPDU
- link
- hwmode
- vepa
- veb - 硬件 bridge
- hwmode
bridge li # link show
bridge fdb # fdb show
bridge mdb # mdb show
bridge vlan # vlan show
bridge monitor
STP
- master 每 2s 发送一次 “心跳”/hello 包
0180c2000000 - slave 接收到包
- 20s 内没收到，则认为 master down
- 30s 内建立好新的 stp - 作为 master
- BPDU - Bridge Protocol Data Unit
角色
| Role | Name | Chinese | Desc |
|---|---|---|---|
| RB | Root Bridge | 根桥 | ID 最小桥 |
| RP | Root Port | 根端口 | 最佳路径端口 |
| DP | Designated Port | 指定端口 | 每一个网段选择到根桥最近的网桥作为指定网桥, 该网桥到这一网段的端口为指定端口 |
| AP | Alternated Port | 可选端口 | 即阻塞端口, 既不是指定端口, 也不是根端口的端口 |
端口状态
| Status | Data | BPDU | Learn Address |
|---|---|---|---|
| Disabled | no | no | no |
| Blocking | no | recv | no |
| Listening | no | yes | no |
| Learning | no | yes | start |
| Forwarding | yes | yes | yes |
- Blocking(20s) –> Listening(15s) –> Learning(15s) –> Forwarding
- 参考
- mstpd/mstpd - Multiple Spanning Tree Protocol Daemon
- wikipedia Spanning Tree Protocol
- wikipedia 生成树协议
- Linux STP 介绍
- Linux BRIDGE-STP-HOWTO
- Spanning Tree Protocol
- Linux: bridges, VLANs and RSTP
FAQ
bridge vs bonding active-backup
- bonding - 用于聚合链路
- 聚合 - 使用同质的链路
- 多个链路并行工作
- active-backup - 可能使用非同质链路 - wlan0+eth0 - eth0 作为 primary
- 检测链路状态 - 切换时间短
- 聚合 - 使用同质的链路
- bridge - 用于学习和转发
- members 可以是虚拟链路，可以是物理链路
- STP - 学习需要时间 - 默认前后加起来 50s - 可能更长
- 理论上来说也能实现 bonding active-backup 的效果
桥接网卡不使用实际网卡 Mac 地址
桥接网卡 MAC 地址会变导致 dhcp 获取的地址不稳定
默认选择最低 mac - 排序最前，一般虚拟网卡的 mac 会比实际的更低，导致被优先选择。
brctl addif 添加 slave 的时候也会变
- 添加 slave 的时候记录 mac 再设置回去
- 将虚拟网卡的 mac 设置高一点
- 推荐
# 方法 1
mac=$(cat /etc/tinc/br0/address)
ip li set $IFACE master br0
ip li set br0 address $mac
# 方法 2
ip link set $IFACE address fe:12:34:56:78:9a
tinc 节点避免 mac 冲突
设置高 mac
ip li set $INTERFACE address fe:fe:12:34:56:78
ip li set $INTERFACE master br0
ip li set $INTERFACE up
ip addr add 10.10.1.1/16 dev br0
received packet on bond0 with own address as source address
影响不大的 log 信息
bridge: filtering via arp/ip/ip6tables is no longer available by default
- 只是 info log，以前 modprobe bridge 会提供的功能现在需要 modprobe br_netfilter
bridge: filtering via arp/ip/ip6tables is no longer available by default. Update your scripts to load br_netfilter if you need this.