水文警告

背景#

从朋友那里弄到一台深港IEPL机器，有两个网卡eth0和eth1，但是默认都走eth0，eth1没有配置路由。
我打算通过metric实现粗略的分流再通过PBR实现按照规则的路由配置。

配置#

机器默认由cloudinit配置了网卡：

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# This file is generated from information provided by the datasource.  Changes
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# to it will not persist across an instance reboot.  To disable cloud-init's
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# network configuration capabilities, write a file
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# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
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# network: {config: disabled}
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network:
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    version: 2
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    ethernets:
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        eth0:
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            addresses:
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            - 10.10.1.31/16
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            gateway4: 10.10.0.1
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            match:
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                macaddress: bc:24:11:f8:42:7a
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            nameservers:
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                addresses:
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                - 223.5.5.5
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                - 119.29.29.29
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                search:
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                - [数据删除]
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            set-name: eth0
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        eth1:
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            addresses:
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            - 10.20.1.31/16
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            - [数据删除]/64
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            gateway4: 10.20.0.1
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            gateway6: fe80::be24:11ff:fe80:66bb
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            match:
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                macaddress: bc:24:11:50:96:0a
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            nameservers:
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                addresses:
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                - 223.5.5.5
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                - 119.29.29.29
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                search:
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                - [数据删除]
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            set-name: eth1

备份一份配置之后加上metric：

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# This file is generated from information provided by the datasource.  Changes
2
# to it will not persist across an instance reboot.  To disable cloud-init's
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# network configuration capabilities, write a file
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# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
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# network: {config: disabled}
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network:
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    version: 2
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    ethernets:
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        eth0:
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            addresses:
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            - 10.10.1.31/16
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            gateway4: 10.10.0.1
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            match:
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                macaddress: bc:24:11:f8:42:7a
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            nameservers:
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                addresses:
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                - 223.5.5.5
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                - 119.29.29.29
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                search:
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                - [数据删除]
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            set-name: eth0
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           routes:
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             - to: "default"
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               via: "10.10.0.1"
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               # 设置 metric=50，作为备选出口
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               metric: 50
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        eth1:
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            addresses:
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            - 10.20.1.31/16
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            - [数据删除]/64
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            gateway4: 10.20.0.1
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            gateway6: fe80::be24:11ff:fe80:66bb
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            match:
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                macaddress: bc:24:11:50:96:0a
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            nameservers:
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                addresses:
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                - 223.5.5.5
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                - 119.29.29.29
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                search:
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                - [数据删除]
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            set-name: eth1
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           routes:
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             - to: "default"
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               via: "10.20.0.1"
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               # 设置 metric=25，作为优先出口
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               metric: 25

编写PBR配置：

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network:
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  version: 2
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  ethernets:
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    eth0:
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      routes:
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        - to: default
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          via: 10.10.0.1
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          table: 10
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      routing-policy:
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        - from: 10.10.0.0/16
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          table: 10
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        - to: 202.46.[数据删除]/32
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          table: 10
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    eth1:
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      routes:
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        - to: default
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          via: 10.20.0.1
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          table: 20
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      routing-policy:
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        - from: 10.20.0.0/16
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          table: 20
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        - to: 38.47.[数据删除]/32
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          table: 20
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        - to: 23.149.[数据删除]/32
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          table: 20

对于需要指定出口访问的IP为其加上to类型的规则并绑定对应路由表即可。

完成后运行

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netplan apply

更新配置