### L3VPN Configuration Example

Source: https://bird.xmsl.dev/docs/user-guide/6-12-l3vpn

A complete configuration example demonstrating an L3VPN setup with BGP peering, kernel VRF integration, and MPLS domain configuration.

```bird2
# MPLS 基础配置
mpls domain mdom;
mpls table  mtab;

protocol kernel krt_mpls {
    mpls { table mtab; export all; };
}

vpn4 table vpntab4;
vpn6 table vpntab6;

# 通过 BGP 交换 VPN 路由
protocol bgp {
    vpn4 { table vpntab4; import all; export all; };
    vpn6 { table vpntab6; import all; export all; };
    mpls { label policy aggregate; };
    local 10.0.0.1 as 10;
    neighbor 10.0.0.2 as 10;
}

# VRF 0
ipv4 table vrf0v4;
ipv6 table vrf0v6;

protocol kernel kernel0v4 {
    vrf "vrf0";
    ipv4 { table vrf0v4; export all; };
    kernel table 100;
}

protocol kernel kernel0v6 {
    vrf "vrf0";
    ipv6 { table vrf0v6; export all; };
    kernel table 100;
}

protocol l3vpn l3vpn0 {
    vrf "vrf0";
    ipv4 { table vrf0v4; };
    ipv6 { table vrf0v6; };
    vpn4 { table vpntab4; };
    vpn6 { table vpntab6; };
    mpls { label policy vrf; };

    rd 10:12;
    import target [(rt, 10, 32..40)];
    export target [(rt, 10, 30), (rt, 10, 31)];
}
```

--------------------------------

### BGP Protocol Configuration Example

Source: https://bird.xmsl.dev/docs/user-guide/6-1-bgp

A complete BGP protocol block demonstrating multi-hop setup, TCP-AO authentication with key management, and protocol-specific export/import filters.

```bird2
protocol bgp {
    local 198.51.100.14 as 65000;        # 使用私有 AS 号
    neighbor 198.51.100.130 as 64496;    # 我们的邻居...
    multihop;                # ...间接连接
    authentication ao;           # 使用 TCP-AO 认证
    keys {
        key {
            id 0;
            secret "hello321";
            algorithm hmac sha256;
            preferred;
        };
        key {
            send id 2;
            recv id 1;
            secret "bye123";
            algorithm cmac aes128;
        };
    };
    ipv4 {
        export filter {              # 使用非平凡的 export 规则
            if source = RTS_STATIC then { # 仅导出静态路由
                # 分配我们的团体属性
                bgp_community.add((65000,64501));
                # 通过两次通告本地 AS 号
                # 人为增加路径长度
                if bgp_path ~ [= 65000 =] then
                    bgp_path.prepend(65000);
                accept;
            }
            reject;
        };
        import all;
        next hop self; # 将本路由器作为下一跳通告
        igp table myigptable4; # IPv4 下一跳的 IGP 表
        igp table myigptable6; # IPv6 下一跳的 IGP 表
    };
    ipv6 {
        export filter mylargefilter; # 使用命名过滤器
        import all;
        missing lladdr self;
        igp table myigptable4;
        igp table myigptable6;
    };
    ipv4 multicast {
        import all;
        export filter someotherfilter;
        table mymulticasttable4; # 另一个 IPv4 表，专用于组播
        igp table myigptable4;
    };
}
```

--------------------------------

### Enable and start BIRD service

Source: https://bird.xmsl.dev/docs/user-guide/1-2-installing

Reload systemd configuration and start the BIRD service.

```bash
systemctl daemon-reload
systemctl enable bird
systemctl start bird
```

--------------------------------

### Compile and install BIRD

Source: https://bird.xmsl.dev/docs/user-guide/1-2-installing

Generate the makefile, configure installation paths, and compile the source code.

```bash
cd BIRD-$_BIRD_VERSION

autoconf

./configure --prefix= --sysconfdir=/etc/bird --runstatedir=/var/run/bird

make && make install
```

--------------------------------

### Install git and curl by distribution

Source: https://bird.xmsl.dev/docs/user-guide/1-2-installing

Install git and curl utilities required for downloading the BIRD source code.

```bash
apt install git curl
```

```bash
dnf install git curl
```

```bash
pacman -Syu --needed git curl
```

```bash
apk add git curl
```

--------------------------------

### Basic BIRD Configuration Example

Source: https://bird.xmsl.dev/docs/user-guide/3-1-introduction

A sample configuration enabling kernel route synchronization, device monitoring, and the RIP protocol.

```cs
protocol kernel {
    ipv4 {
        export all;     /* 在此配置下导出 `master4` 表的路由到内核，默认配置则是不导出路由 */
    };
    persist;            /* 在 BIRD 关闭时不收回路由 */
}

protocol device {
}

protocol rip {
    ipv4 {
        import all;
        export all;
    };
    interface "*";     /* 使用所有的网络接口 */
}
```

--------------------------------

### Install BIRD on Fedora/RHEL

Source: https://bird.xmsl.dev/docs/user-guide/1-2-installing

Installs BIRD using the dnf package manager.

```bash
dnf install bird
```

--------------------------------

### Install BIRD on Arch Linux

Source: https://bird.xmsl.dev/docs/user-guide/1-2-installing

Installs BIRD from the Extra repository using pacman.

```bash
pacman -Syu --needed --repository=extra bird
```

--------------------------------

### Start BIRD service on Alpine Linux

Source: https://bird.xmsl.dev/docs/user-guide/1-2-installing

Enables and starts the BIRD service using OpenRC.

```bash
# 启用并启动 BIRD 服务
rc-update add bird default
rc-service bird start
```

--------------------------------

### Install BIRD 2.x on Debian/Ubuntu via CZ.NIC

Source: https://bird.xmsl.dev/docs/user-guide/1-2-installing

Installs BIRD 2.x using the official CZ.NIC repository.

```bash
sudo apt update && sudo apt -y install apt-transport-https ca-certificates wget lsb-release
sudo wget -O /usr/share/keyrings/cznic-labs-pkg.gpg https://pkg.labs.nic.cz/gpg

echo "deb [signed-by=/usr/share/keyrings/cznic-labs-pkg.gpg] https://pkg.labs.nic.cz/bird2 $(lsb_release -sc) main" | sudo tee /etc/apt/sources.list.d/cznic-labs-bird2.list

sudo apt update && sudo apt install bird2
```

--------------------------------

### Install BIRD 3.x on Debian/Ubuntu via CZ.NIC

Source: https://bird.xmsl.dev/docs/user-guide/1-2-installing

Installs BIRD 3.x using the official CZ.NIC repository.

```bash
sudo apt update && sudo apt -y install apt-transport-https ca-certificates wget lsb-release
sudo wget -O /usr/share/keyrings/cznic-labs-pkg.gpg https://pkg.labs.nic.cz/gpg

echo "deb [signed-by=/usr/share/keyrings/cznic-labs-pkg.gpg] https://pkg.labs.nic.cz/bird3 $(lsb_release -sc) main" | sudo tee /etc/apt/sources.list.d/cznic-labs-bird3.list

sudo apt update && sudo apt install bird3
```

--------------------------------

### Install BIRD 2.x on Ubuntu via noble channel

Source: https://bird.xmsl.dev/docs/user-guide/1-2-installing

Installs BIRD 2.x by adding the noble repository channel.

```bash
echo "deb http://archive.ubuntu.com/ubuntu/ $(lsb_release -sc)-noble main contrib non-free" | tee -a /etc/apt/sources.list
apt update
apt install -t $(lsb_release -sc)-noble bird2
```

--------------------------------

### Install BIRD on Alpine Linux

Source: https://bird.xmsl.dev/docs/user-guide/1-2-installing

Commands to install BIRD on Alpine Linux from Edge or stable repositories.

```bash
# 添加 Edge 社区仓库
echo "https://dl-cdn.alpinelinux.org/alpine/edge/community" >> /etc/apk/repositories

# 更新包索引并安装 BIRD
apk update && apk add bird
```

```bash
# 启用社区仓库（如果尚未启用）
sed -i 's/#.*community//' /etc/apk/repositories

# 更新包索引并安装 BIRD
apk update && apk add bird
```

--------------------------------

### Install build dependencies by distribution

Source: https://bird.xmsl.dev/docs/user-guide/1-2-installing

Install necessary build tools and libraries required for compiling BIRD on various Linux distributions.

```bash
apt install gcc make binutils m4 flex bison libncurses-dev libreadline-dev autoconf
```

```bash
dnf install gcc make binutils m4 flex bison ncurses-devel readline-devel autoconf
```

```bash
pacman -Syu --needed gcc make binutils m4 flex bison ncurses readline autoconf
```

```bash
apk add gcc make binutils m4 flex bison ncurses-dev readline-dev autoconf
```

--------------------------------

### Multi-Table Kernel Protocol Configuration

Source: https://bird.xmsl.dev/docs/user-guide/6-5-kernel

An example demonstrating how to configure multiple kernel protocol instances for different routing tables, including learning and persistence settings.

```bird2
protocol kernel {       # 主路由表
    learn;          # 从内核学习外来路由
    persist;        # BIRD 关闭时不删除路由
    scan time 10;       # 每 10 秒扫描内核路由表
    ipv4 {
        import all;
        export all;
    };
}

protocol kernel {       # 辅路由表
    kernel table 100;
    ipv4 {
        table auxtable;
        export all;
    };
}
```

--------------------------------

### Install BIRD 2.x on Debian via Backports

Source: https://bird.xmsl.dev/docs/user-guide/1-2-installing

Installs BIRD 2.x using the Debian Backports channel.

```bash
echo "deb http://deb.debian.org/debian $(lsb_release -sc)-backports main" > tee -a /etc/apt/sources.list
apt update
apt install -t $(lsb_release -sc)-backports bird2
```

--------------------------------

### Direct Protocol Configuration Example

Source: https://bird.xmsl.dev/docs/user-guide/6-7-direct

A standard configuration for the Direct protocol, enabling both IPv4 and IPv6, filtering interfaces, and enabling link state checks.

```bird2
protocol direct {
    ipv4;                           # 自动生成 IPv4 路由
    ipv6;                           # 自动生成 IPv6 路由
    interface "-arc*", "*";         # 排除 ARCnets
    check link yes;                 # 检查链路状态
}
```

--------------------------------

### BIRD 2 BGP Configuration Example

Source: https://bird.xmsl.dev/docs/collections/bird-bgp-kickstart-moesoha

A comprehensive configuration file for BIRD 2, implementing static routes, BGP templates, and specific import/export filters for transit and peer sessions.

```bird2
log syslog all;

router id 10.0.0.1;
define LOCAL_ASN = 65550;

protocol device {}

protocol kernel {
    ipv6 { export all; };
}

# 公网上约定俗成的最小前缀长度是 24（IPv4）和 48（IPv6），所以要在导出的时候过滤
function net_len_too_long(){
    case net.type {
        NET_IP4: return net.len > 24; # IPv4 CIDR 大于 /24 为太长
        NET_IP6: return net.len > 48; # IPv6 CIDR 大于 /48 为太长
        else: print "net_len_too_long: unexpected net.type ", net.type, " ", net; return false;
    }
}

# 目标 1
function bgp_export() {
    if net_len_too_long() then return false;
    if source != RTS_STATIC then return false;
    if net !~ [2001:db8:1000::/44{44,46}] then return false;
    return true;
}

# 目标 2
protocol static {
    ipv6;
    route 2001:db8:1000::/44 reject;
}

# 目标 8
protocol static {
    ipv6;
    route 2001:db8:100a::/48 via "tun-a";
}

# 使用模板减少重复代码
template bgp tpl_bgp {
    graceful restart;
    local as LOCAL_ASN;
    ipv6 {
        import where !net_len_too_long();
        export where bgp_export();
    };
}
template bgp tpl_ibgp from tpl_bgp {
    med metric;
    direct;
    ipv6 {
        next hop self;
        gateway direct;
        import all;
        export all;
    };
}

# 目标 3
protocol bgp bgp_as64501 from tpl_bgp {
    source address 2001:db8:ffff:1::6:5550;
    neighbor 2001:db8:ffff:1::6:4501 as 64501;
    ipv6 {
        import filter {
            if net_len_too_long() then reject;
            if (64501, 1, 65511) ~ bgp_large_community then reject; # 目标 5
            accept;
        };
        export filter {
            if !bgp_export() then reject;
            bgp_community.add((0, 65510)); # 目标 4
            accept;
        }
    };
}

# 目标 6
protocol bgp bgp_as64502 from tpl_bgp {
    source address 2001:db8:ffff:2::6:5550;
    neighbor 2001:db8:ffff:2::6:4502 as 64502;
    ipv6 {
        import filter {
            if net_len_too_long() then reject;
            bgp_local_pref = 1000; # 目标 7
            accept;
        };
        # export 使用了 template 中的默认值
    };
}

# 目标 9
protocol bgp ibgp_b from tpl_ibgp {
    source address 2001:db8:eeee:b::1;
    neighbor 2001:db8:eeee:b::b as LOCAL_ASN;
}
```

--------------------------------

### Configure RAdv Protocol in BIRD 2

Source: https://bird.xmsl.dev/docs/user-guide/6-15-radv

Example configuration demonstrating static route propagation, interface-specific settings, and RDNSS/DNSSL options.

```bird2
ipv6 table radv_routes;         # 手动配置的路由放到这里

protocol static {
    ipv6 { table radv_routes; };

    route 2001:0DB8:4000::/48 unreachable;
    route 2001:0DB8:4010::/48 unreachable;

    route 2001:0DB8:4020::/48 unreachable {
        ra_preference = RA_PREF_HIGH;
        ra_lifetime = 3600;
    };
}

protocol radv {
    propagate routes yes;       # 传播来自 radv_routes 表的路由
    ipv6 { table radv_routes; export all; };

    interface "eth2" {
        max ra interval 5;  # 多路由器场景下的快速故障切换
        managed yes;        # 在 eth2 上使用 DHCPv6
        prefix ::/0 {
            autonomous off; # 因此不自动配置任何 IP
        };
    };

    interface "eth*";       # 其他接口无需任何选项

    prefix 2001:0DB8:1234::/48 {
        preferred lifetime 0;   # 已弃用的地址范围
    };

    prefix 2001:0DB8:2000::/48 {
        autonomous off;     # 不进行自动配置
    };

    rdnss 2001:0DB8:1234::10;   # RDNSS 简写形式

    rdnss {
        lifetime mult 10;
        ns 2001:0DB8:1234::11;
        ns 2001:0DB8:1234::12;
    };

    dnssl {
        lifetime 3600;
        domain "abc.com";
        domain "xyz.com";
    };
}
```

--------------------------------

### Configure Static Routes in BIRD

Source: https://bird.xmsl.dev/docs/user-guide/6-4-static

Examples of static protocol blocks for IPv4 and IPv6, demonstrating various route types, next-hop configurations, and attribute settings.

```bird2
protocol static {
    ipv4 { table testable; };   # 连接到非默认路由表
    check link;         # 仅在链路正常时宣告路由
    route 0.0.0.0/0 via 198.51.100.130; # 默认路由
    route 10.0.0.0/8        # 多路径路由
        via 198.51.100.10 weight 2
        via 198.51.100.20 bfd   # BFD 控制的下一跳
        via 192.0.2.1;
    route 203.0.113.0/24 blackhole; # 沉没路由
    route 10.2.0.0/24 via "arc0";   # 直连路由
    route 10.2.2.0/24 via 192.0.2.1 dev "eth0" onlink; # 同时指定下一跳和接口
    route 192.168.10.0/24 via 198.51.100.100 {
        ospf_metric1 = 20;  # 设置扩展属性
    };
    route 192.168.11.0/24 via 198.51.100.100 {
        ospf_metric2 = 100; # 设置扩展属性
        ospf_tag = 2;       # 设置扩展属性
    };
    route 192.168.12.0/24 via 198.51.100.100 {
        bgp_community.add((65535, 65281));  # 设置扩展 BGP 属性
        bgp_large_community.add((64512, 1, 1)); # 设置扩展 BGP 属性
    };
}
```

```bird2
protocol static {
    ipv6;                       # 通道是必选的
    route 2001:db8:10::/48 via 2001:db8:1::1;   # 全局下一跳路由
    route 2001:db8:20::/48 via fe80::10%eth0;   # 链路本地下一跳路由
    route 2001:db8:30::/48 via fe80::20%'eth1.60';  # 含特殊字符的接口
    route 2001:db8:40::/48 via fe80::30 dev "eth1"; # 另一种链路本地下一跳
    route 2001:db8:50::/48 via "eth2";      # 指向 eth2 的直连路由
    route 2001:db8::/32 unreachable;        # 不可达路由
    route ::/0 via 2001:db8:1::1 bfd;       # BFD 控制的默认路由
}
```

--------------------------------

### Configure Protocol Channels

Source: https://bird.xmsl.dev/docs/collections/bird-bgp-kickstart-moesoha

Example of configuring import/export filters and route limits within a protocol channel.

```bird2
protocol some_proto {
    /* 略 */
    ipv6 {
        export filter some_filter1;
        import filter some_filter2;
        # 下面这两个是可选项，默认是不做限制的
        export limit 100 action disable; # 导出的路由数量多于 100 后自动停止该协议，避免传出过多路由（往往这个时候是漏路由了）
        import limit 100 action restart; # 导入的路由数量多于 100 后自动重启该协议，限制对端传入的路由数
    };
}
```

--------------------------------

### Check BIRD version

Source: https://bird.xmsl.dev/docs/user-guide/1-2-installing

Command to verify the currently installed version of BIRD.

```bash
birdc -v
```

--------------------------------

### Configure BIRD Device Protocol

Source: https://bird.xmsl.dev/docs/user-guide/6-6-device

Example configuration for the device protocol, including scan interval settings and preferred IP address definitions for specific interfaces.

```bird2
protocol device {
    scan time 10;                    #扫描间隔 10 秒
    interface "eth0" {               #指定网卡 eth0
        preferred 192.168.1.1;       #选择优先的 IPv4 地址
        preferred 2001:db8:1:10::1;  #选择优先的 IPv6 地址
        preferred fd00::1;           #选择优先的 IPv6 本地链路地址
    };
}
```

--------------------------------

### OSPF Protocol Configuration

Source: https://bird.xmsl.dev/docs/user-guide/6-2-ospf

Example configuration for an OSPF protocol instance, including export filters, area definitions, interface settings, and authentication methods.

```bird2
protocol ospf MyOSPF {
    ipv4 {
        export filter {
            if source = RTS_BGP then {
                ospf_metric1 = 100;
                accept;
            }
            reject;
        };
    };
    area 0.0.0.0 {
        interface "eth*" {
            cost 11;
            hello 15;
            priority 100;
            retransmit 7;
            authentication simple;
            password "aaa";
        };
        interface "ppp*" {
            cost 100;
            authentication cryptographic;
            password "abc" {
                id 1;
                generate to "2023-04-22 11:00:06";
                accept from "2021-01-17 12:01:05";
                algorithm hmac sha384;
            };
            password "def" {
                id 2;
                generate to "2025-07-22";
                accept from "2021-02-22";
                algorithm hmac sha512;
            };
        };
        interface "arc0" {
            cost 10;
            stub yes;
        };
        interface "arc1";
    };
    area 120 {
        stub yes;
        networks {
            172.16.1.0/24;
            172.16.2.0/24 hidden;
        };
        interface "-arc0" , "arc*" {
            type nonbroadcast;
            authentication none;
            strict nonbroadcast yes;
            wait 120;
            poll 40;
            dead count 8;
            neighbors {
                192.168.120.1 eligible;
                192.168.120.2;
                192.168.120.10;
            };
        };
    };
}
```

--------------------------------

### Configure BIRD Pipe Protocol for Policy Routing

Source: https://bird.xmsl.dev/docs/user-guide/6-11-pipe

Example demonstrating the use of two routing tables (as1 and as2) with kernel synchronization, BGP protocols, and a pipe protocol to exchange routes with modified preferences and BGP paths.

```bird2
ipv4 table as1;             # 定义路由表
ipv4 table as2;

protocol kernel kern1 {         # 与内核同步
    ipv4 { table as1; export all; };
    kernel table 1;
}

protocol kernel kern2 {
    ipv4 { table as2; export all; };
    kernel table 2;
}

protocol bgp bgp1 {         # 外部连接
    ipv4 { table as1; import all; export all; };
    local as 1;
    neighbor 192.168.0.1 as 1001;
}

protocol bgp bgp2 {
    ipv4 { table as2; import all; export all; };
    local as 2;
    neighbor 10.0.0.1 as 1002;
}

protocol pipe {             # 管道协议
    table as1;
    peer table as2;
    export filter {
        if net ~ [ 1.0.0.0/8+] then {   # 仅 AS1 网络
            if preference>10 then preference = preference-10;
            if source=RTS_BGP then bgp_path.prepend(1);
            accept;
        }
        reject;
    };
    import filter {
        if net ~ [ 2.0.0.0/8+] then {   # 仅 AS2 网络
            if preference>10 then preference = preference-10;
            if source=RTS_BGP then bgp_path.prepend(2);
            accept;
        }
        reject;
    };
}
```

--------------------------------

### Specify Configuration and Socket Paths

Source: https://bird.xmsl.dev/docs/user-guide/1-3-running

Use -c to define the configuration file path and -s to define the control socket path.

```bash
$ bird -c /path/to/bird.conf
```

```bash
$ bird -s /path/to/bird.ctl
```

--------------------------------

### Display Help Information

Source: https://bird.xmsl.dev/docs/user-guide/1-3-running

Shows command-line help for BIRD.

```bash
$ bird -h
```

```bash
$ bird --help
```

--------------------------------

### Run in Foreground

Source: https://bird.xmsl.dev/docs/user-guide/1-3-running

Starts BIRD in the foreground without outputting debug information.

```bash
$ bird -f
```

--------------------------------

### Run in Debug Mode

Source: https://bird.xmsl.dev/docs/user-guide/1-3-running

Starts BIRD in the foreground with verbose debugging output.

```bash
$ bird -d
```

--------------------------------

### Define Bytestring

Source: https://bird.xmsl.dev/docs/user-guide/5-2-data-types

Examples of defining bytestrings using hexadecimal sequences or the from_hex function.

```text
01:23:45:67:89:ab:cd:ef:01:23:45:67:89:ab:cd:ef
0123456789abcdef0123456789abcdef
hex:
hex:12:34:56
hex:12345678
from_hex(" 12.34 56:78 ab-cd-ef ")
```

--------------------------------

### Protocol Instance Syntax

Source: https://bird.xmsl.dev/docs/collections/bird-bgp-kickstart-moesoha

The general structure for defining a protocol instance in BIRD configuration.

```bird2
protocol <协议> [实例名] {
    /* 参数们 */
    <频道> {
        /* 频道参数 */
    }
}
```

--------------------------------

### Define a BIRD Function

Source: https://bird.xmsl.dev/docs/collections/bird-bgp-kickstart-moesoha

A function example showing parameter definition, local variables, and the use of 'case' statements for network type checking.

```bird2
function net_len_too_long(int hello)
# 这里定义的参数 hello 没啥意义，只是让大家知道可以定义参数，不定义括号内留空即可
int world; {
# ^ 这里的变量定义没啥意义，只是让大家知道可以定义局部变量
    case net.type {
        NET_IP4: return net.len > 24; # IPv4 CIDR 大于 /24 为太长
        NET_IP6: return net.len > 48; # IPv6 CIDR 大于 /48 为太长
        else: print "net_len_too_long: unexpected net.type ", net.type, " ", net; return false;
    }
}
```

--------------------------------

### configure

Source: https://bird.xmsl.dev/docs/user-guide/4-command-line-interface

Commands for reloading, checking, and rolling back BIRD configurations.

```APIDOC
## configure [soft] ["config file"] [timeout [num]]

### Description
Reloads the configuration from a file. Supports soft reloads to avoid protocol restarts and timed rollbacks for safety.

## configure confirm

### Description
Confirms a configuration change and disables the rollback timer.

## configure undo

### Description
Rolls back to the previously saved configuration.

## configure check ["config file"]

### Description
Parses and validates the specified configuration file without applying it.
```

--------------------------------

### BIRD 文档翻译计划邮件模板

Source: https://bird.xmsl.dev/pages/join-us

用于申请加入 git 组织或直接提交文档翻译内容的邮件格式模板。

```txt
To: join-bird@xmsl.dev
Subject: 申请加入 BIRD 中文文档翻译计划

我是 {昵称}，我希望加入 BIRD 中文文档翻译计划，我 Email 地址为 {你的邮箱地址}。

我同意遵守 BIRD 中文文档翻译计划的所有规定，我将尽我所能为 BIRD 中文文档翻译计划做出贡献。

我已阅读并同意 CC BY-NC-SA 4.0 协议。
```

```txt
To: bird@xmsl.dev
Subject: BIRD-CN 文档投稿 / {翻译文档名称}

我是 {昵称}，我希望投稿 BIRD 中文文档翻译计划，我 Email 地址为 {你的邮箱地址}。

[markdown 文档内容附件]
```

--------------------------------

### Display Version Information

Source: https://bird.xmsl.dev/docs/user-guide/1-3-running

Outputs the current version of BIRD.

```bash
$ bird --version
```

--------------------------------

### Define ROA entries in JSON

Source: https://bird.xmsl.dev/docs/user-guide/2-2-routes-and-network-types

Example structure for defining ROA (Route Origin Authorization) entries for IPv4 and IPv6 to validate BGP route origins.

```json
{
  "roa4": [
    {
      // [!code focus]
      "prefix": "198.18.0.0/16", // [!code focus]
      "maxLength": 24, // [!code focus]
      "asn": 123456 // [!code focus]
    }
  ],
  "roa6": [
    {
      // [!code focus]
      "prefix": "2001:db8::/32", // [!code focus]
      "maxLength": 48, // [!code focus]
      "asn": 123456 // [!code focus]
    }
  ]
}
```

--------------------------------

### 引入配置文件

Source: https://bird.xmsl.dev/docs/user-guide/3-2-global-options

使用 include 语句在配置文件中引入其他文件，必须位于行首。

```shell
ipv6 table
include "tablename.conf";; # include 位于所在行的开头
```

--------------------------------

### 调试 BIRD 过滤器命令行示例

Source: https://bird.xmsl.dev/docs/user-guide/5-1-introduction

通过 birdc 客户端与 BIRD 交互，使用 show route 命令测试过滤器逻辑。

```bash
$ birdc -s bird.ctl
```

```bash
bird> show route
10.0.0.0/8         dev eth0 [direct1 23:21] (240)
195.113.30.2/32    dev tunl1 [direct1 23:21] (240)
127.0.0.0/8        dev lo [direct1 23:21] (240)
```

```bash
bird> show route ?
show route [<prefix>] [table <t>] [filter <f>] [all] [primary]...
```

```bash
bird> show route filter { if 127.0.0.5 ~ net then accept; }
127.0.0.0/8        dev lo [direct1 23:21] (240)
```

--------------------------------

### Create systemd service file

Source: https://bird.xmsl.dev/docs/user-guide/1-2-installing

Define the systemd unit file for managing the BIRD daemon.

```ini
# /etc/systemd/system/bird.service

[Unit]
Description="BIRD Internet Routing Daemon"
After=network.target

[Service]
Type=simple
ExecStartPre=/usr/sbin/bird -p
ExecReload=/usr/sbin/birdc configure
ExecStart=/usr/sbin/bird -f -u bird -g bird
Restart=on-abort

[Install]
WantedBy=multi-user.target
```