> For the complete documentation index, see [llms.txt](https://docs.console.zenlayer.com/welcome/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.console.zenlayer.com/welcome/cn/elastic-compute/get-started/manage-instances/bind-an-elastic-ipv4-address.md).

# 绑定弹性 IPv4 地址

您可以将最多 4 个弹性 IPv4 地址绑定到一个内网 IP。

## 操作步骤

1. 单击实例名称，进入实例 **详情** > **信息** > **网卡**。
2. 选择您要绑定弹性 IPv4 的内网 IP，然后进入 **操作** > **绑定弹性 IPv4**。

   <figure><img src="/files/rShLXjK8QbDnKxtPhl26" alt=""><figcaption></figcaption></figure>
3. 选择一个所需的弹性 IPv4 地址并点击 **确认** 进行绑定。如果没有所需的弹性 IPv4 地址，点击 **新建弹性 IPv4** 创建一个新的 IPv4。\
   详细步骤请参见 [**创建弹性 IPv4**](/welcome/cn/elastic-compute/get-started/manage-networking/create-an-elastic-ipv4.md)。

   <div align="left"><figure><img src="/files/l1LBOKZr1u9pd7YuySo3" alt="" width="444"><figcaption></figcaption></figure></div>

{% hint style="info" %} <mark style="color:blue;">**注意**</mark>

<mark style="color:blue;">您也可以进入</mark> <mark style="color:blue;">**弹性 IPv4**</mark> <mark style="color:blue;">></mark> <mark style="color:blue;">**操作**</mark> <mark style="color:blue;">></mark> <mark style="color:blue;">**绑定内网 IP**</mark> <mark style="color:blue;">来绑定弹性 IPv4 地址。</mark>

<img src="/files/ryKGgZz8cZBVZWcMV64a" alt="" data-size="original">
{% endhint %}

## **Bypass 模式配置指南**

#### 1. 适用范围与前提条件

**1.1 适用场景**

* 仅支持**单网卡（NIC）环境**
* 支持多个 IP（最多 254 个）
* **所有 IP 必须为 Bypass 模式**

**1.2 支持的操作系统**

* Ubuntu：20.04 / 22.04 / 24.04
* Debian：10 / 11 / 12
* CentOS：7 / 9
* Rocky Linux：8.10 / 9.6

**1.3 注意事项**

* 执行脚本后必须重启，否则配置不会生效
* 不支持混合模式（Bypass 模式 + NAT 模式）

#### 2. 操作步骤

{% tabs %}
{% tab title="Console" %}

1. 创建命令：

路径：

> 控制台 → 编排服务 → 命令 → 创建命令

{% code expandable="true" %}

```shellscript
#!/bin/sh -e
# Task Description:
#   Used for initializing configuration in single NIC EIP full Bypass mode scenarios.
#   Supports from 1 public IP up to 254 public IPs.
#   Execute this task after external resource environment is ready.
#   Adapted for ubuntu20.04, 22.04, 24.04, debian10, 11, 12, centos7, centos9, rocky9.6, rocky8.10 (10 systems)

# ===== Global Variable Definitions =====
TASK_NAME=single_nic_bypass_init

META_CURL="curl -sf"
META_URL="http://169.254.169.254/latest/meta-data/network/interfaces/macs"

NIC_NAME=eth0
PRI_GW4=
PRI_IP4=
PRI_PREFIX=

SYSTEM=

DEFAULT_PUB_EIP4=
ALL_PUB_EIP4s=

NAME_SERVER1=8.8.8.8
NAME_SERVER2=1.1.1.1
# =======================

CheckSupportedOS() {
    if [ ! -f /etc/os-release ]; then
        echo "Error: Unsupported system: /etc/os-release not found"
        exit 1
    fi

    . /etc/os-release

    if [ "$ID" = "ubuntu" ]; then
        if [ "$VERSION_ID" = "20.04" ] || [ "$VERSION_ID" = "22.04" ] || [ "$VERSION_ID" = "24.04" ]; then
            echo "Supported OS: Ubuntu $VERSION_ID"
            SYSTEM=ubuntu
            return 0
        else
            echo "Error: Unsupported Ubuntu version: $VERSION_ID"
            exit 1
        fi
    elif [ "$ID" = "debian" ]; then
        if [ "$VERSION_ID" = "11" ] || [ "$VERSION_ID" = "10" ] || [ "$VERSION_ID" = "12" ]; then
            echo "Supported OS: Debian $VERSION_ID"
            SYSTEM=debian
            return 0
        else
            echo "Unsupported Debian version: $VERSION_ID"
            exit 1
        fi
    elif [ "$ID" = "centos" ] || [ "$ID" = "rhel" ]; then
        if [ "$VERSION_ID" = "7" ] && [ -f /etc/centos-release ]; then
            echo "Supported OS: CentOS $VERSION_ID"
            SYSTEM=centos
            return 0
        elif [ "$VERSION_ID" = "9" ] && [ -f /etc/centos-release ]; then
            echo "Supported OS: CentOS $VERSION_ID"
            SYSTEM=centos
            return 0
        else
            echo "Unsupported CentOS/RHEL version: $VERSION_ID"
            exit 1
        fi
    elif [ "$ID" = "rocky" ]; then
        if [ "$VERSION_ID" = "9.6" ] || [ "$VERSION_ID" = "8.10" ]; then
            echo "Supported OS: rocky $VERSION_ID"
            SYSTEM=rocky
            return 0
        else
            echo "Unsupported rocky version: $VERSION_ID"
            exit 1
        fi
    else
        echo "Unsupported OS: $ID $VERSION_ID"
        exit 1
    fi
}

ConfigUbuntuNetwork() {
    cat > /etc/netplan/50-cloud-init.yaml << EOF
network:
    version: 2
    ethernets:
        eth0:
            addresses:
                - ${PRI_IP4}/${PRI_PREFIX}
EOF

    for EIP in $ALL_PUB_EIP4s; do
        echo "                - ${EIP}/32" >> /etc/netplan/50-cloud-init.yaml
    done

    cat >> /etc/netplan/50-cloud-init.yaml << EOF
            nameservers:
                addresses:
                - ${NAME_SERVER1}
                - ${NAME_SERVER2}
EOF
    # Default route
    cat >> /etc/netplan/50-cloud-init.yaml << EOF
            routes:
                - to: default
                  via: ${PRI_GW4}
                  from: ${DEFAULT_PUB_EIP4}
EOF
}

ConfigCentOSNetwork() {
    rm -f /etc/sysconfig/network-scripts/ifcfg-eth0*
    cat << EOF > /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
BOOTPROTO=static
ONBOOT=yes
IPADDR=${PRI_IP4}
PREFIX=${PRI_PREFIX}
EOF

index=0

    for EIP in $ALL_PUB_EIP4s; do
        cat << EOF > /etc/sysconfig/network-scripts/ifcfg-eth0:$index
DEVICE=eth0:$index
BOOTPROTO=static
ONBOOT=yes
IPADDR=${EIP}
PREFIX=32
EOF
        index=$((index+1))
    done

    # Default route
    cat << EOF > /etc/sysconfig/network-scripts/route-eth0
default via ${PRI_GW4} dev eth0 src ${DEFAULT_PUB_EIP4}
EOF
    # Disable DHCP on eth2
    cat << EOF > /etc/sysconfig/network-scripts/ifcfg-eth2
DEVICE=eth2
BOOTPROTO=none
ONBOOT=yes
EOF
}

ConfigDebianNetwork() {
    cat > /etc/network/interfaces.d/50-cloud-init << EOF

auto lo
iface lo inet loopback
    dns-nameservers ${NAME_SERVER1} ${NAME_SERVER2}

auto eth0
iface eth0 inet static
    address ${PRI_IP4}/${PRI_PREFIX}

auto eth0:0
iface eth0:0 inet static
    address ${DEFAULT_PUB_EIP4}/32
    up ip route add default via ${PRI_GW4} dev eth0 src ${DEFAULT_PUB_EIP4}
    down ip route del default via ${PRI_GW4} dev eth0 src ${DEFAULT_PUB_EIP4}
EOF

    index=1

    for EIP in $ALL_PUB_EIP4s; do
        if [ "$EIP" = "$DEFAULT_PUB_EIP4" ]; then
            continue
        fi
        cat >> /etc/network/interfaces.d/50-cloud-init << EOF

auto eth0:$index
iface eth0:$index inet static
    address ${EIP}/32
EOF
       index=$((index+1))
    done
}

FetchMetaData() {
    pri_macs=$($META_CURL $META_URL/ | sed 's/\///g')

    nic_count=$(echo "$pri_macs" | wc -w | tr -d ' ')
    if [ "$nic_count" -ne 1 ]; then
        echo "[ERR] Expected exactly one nic, got $nic_count: $pri_macs" >&2
        exit 4
    fi

    PRI_IP4=$($META_CURL $META_URL/$pri_macs/primary-ip-address)
    pri_subnet_cidr=$($META_CURL $META_URL/$pri_macs/subnet-cidr-block)
    PRI_PREFIX=$(echo "$pri_subnet_cidr" | cut -d'/' -f2)
    PRI_GW4=$($META_CURL $META_URL/$pri_macs/gateway)
    DEFAULT_PUB_EIP4=$($META_CURL $META_URL/$pri_macs/public-ipv4)
    ALL_PUB_EIP4s=$($META_CURL $META_URL/$pri_macs/public-ipv4s | sed 's/\[//;s/\]//;s/"//g;s/,/ /g')

    if [ -z "$pri_macs" ] || [ -z "$PRI_IP4" ] || [ -z "$pri_subnet_cidr" ] || [ -z "$PRI_PREFIX" ] || [ -z "$PRI_GW4" ] || [ -z "$DEFAULT_PUB_EIP4" ] || [ -z "$ALL_PUB_EIP4s" ]; then
        echo "[ERR] Missing metadata, check EC2 metadata service." >&2
        exit 3
    fi

    echo "  Private MacAddr:     $pri_macs"
    echo "  Private IPv4:        $PRI_IP4"
    echo "  Private Prefix:      $PRI_PREFIX"
    echo "  Private GWv4:        $PRI_GW4"
    echo "  ALl Public IPv4:     $ALL_PUB_EIP4s"
    echo "  Default Public IPv4: $DEFAULT_PUB_EIP4"
}

ConfigNetwork() {
    # Disable RPF (Reverse Path Filtering)
    if ! grep -q "net.ipv4.conf.all.rp_filter=0" /etc/sysctl.conf; then
        echo "net.ipv4.conf.all.rp_filter=0" | tee -a /etc/sysctl.conf > /dev/null
        sysctl -p /etc/sysctl.conf
    fi

    # Disable cloud-init network configuration
    echo "network: {config: disabled}" > /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg

    if [ "$SYSTEM" = "ubuntu" ]; then
        ConfigUbuntuNetwork
    elif [ "$SYSTEM" = "centos" ]; then
        ConfigCentOSNetwork
    elif [ "$SYSTEM" = "debian" ]; then
        if [ "$VERSION_ID" = "11" ] || [ "$VERSION_ID" = "10" ]; then
            ConfigDebianNetwork
        elif [ "$VERSION_ID" = "12" ]; then
            ConfigUbuntuNetwork
        else
            echo "Unsupported Debian version: $VERSION_ID"
            exit 1
        fi
    elif [ "$SYSTEM" = "rocky" ]; then
        ConfigCentOSNetwork
    else
        echo "Unsupported OS for network config: $SYSTEM"
        exit 1
    fi
}

echo "1. Check OS..."
CheckSupportedOS

echo

echo "2. FetchMetaData..."
FetchMetaData

echo

echo "3. Configuring networks..."
ConfigNetwork

echo

echo
echo "Done."

sync

```

{% endcode %}

2. 运行命令：

路径：

> 控制台 → 云服务器 → 云服务器实例列表 → 操作 → 运维 → 执行命令 → 选择命令 → 确认

运行已创建的命令。

3. 重启实例：\
   执行完成后，必须手动重启实例。
4. 添加额外 IP（可选）：\
   如需绑定更多 IP，请重复以下步骤：

* 绑定 IP
* 执行命令
* 重启实例
  {% endtab %}

{% tab title="API" %}

1. 创建计算实例：\
   按照标准流程创建一个实例。
2. 创建并绑定 EIP：\
   创建一个弹性公网 IP（EIP）。\
   将其以 Bypass 模式绑定到实例上。
3. 通过 API 运行命令：\
   API 文档：\
   <https://docs.console.zenlayer.com/api-reference/security/zos/command/createcommand>\
   使用下方提供的脚本

{% code expandable="true" %}

```shellscript
#!/bin/sh -e
# Task Description:
#   Used for initializing configuration in single NIC EIP full Bypass mode scenarios.
#   Supports from 1 public IP up to 254 public IPs.
#   Execute this task after external resource environment is ready.
#   Adapted for ubuntu20.04, 22.04, 24.04, debian10, 11, 12, centos7, centos9, rocky9.6, rocky8.10 (10 systems)

# ===== Global Variable Definitions =====
TASK_NAME=single_nic_bypass_init

META_CURL="curl -sf"
META_URL="http://169.254.169.254/latest/meta-data/network/interfaces/macs"

NIC_NAME=eth0
PRI_GW4=
PRI_IP4=
PRI_PREFIX=

SYSTEM=

DEFAULT_PUB_EIP4=
ALL_PUB_EIP4s=

NAME_SERVER1=8.8.8.8
NAME_SERVER2=1.1.1.1
# =======================

CheckSupportedOS() {
    if [ ! -f /etc/os-release ]; then
        echo "Error: Unsupported system: /etc/os-release not found"
        exit 1
    fi

    . /etc/os-release

    if [ "$ID" = "ubuntu" ]; then
        if [ "$VERSION_ID" = "20.04" ] || [ "$VERSION_ID" = "22.04" ] || [ "$VERSION_ID" = "24.04" ]; then
            echo "Supported OS: Ubuntu $VERSION_ID"
            SYSTEM=ubuntu
            return 0
        else
            echo "Error: Unsupported Ubuntu version: $VERSION_ID"
            exit 1
        fi
    elif [ "$ID" = "debian" ]; then
        if [ "$VERSION_ID" = "11" ] || [ "$VERSION_ID" = "10" ] || [ "$VERSION_ID" = "12" ]; then
            echo "Supported OS: Debian $VERSION_ID"
            SYSTEM=debian
            return 0
        else
            echo "Unsupported Debian version: $VERSION_ID"
            exit 1
        fi
    elif [ "$ID" = "centos" ] || [ "$ID" = "rhel" ]; then
        if [ "$VERSION_ID" = "7" ] && [ -f /etc/centos-release ]; then
            echo "Supported OS: CentOS $VERSION_ID"
            SYSTEM=centos
            return 0
        elif [ "$VERSION_ID" = "9" ] && [ -f /etc/centos-release ]; then
            echo "Supported OS: CentOS $VERSION_ID"
            SYSTEM=centos
            return 0
        else
            echo "Unsupported CentOS/RHEL version: $VERSION_ID"
            exit 1
        fi
    elif [ "$ID" = "rocky" ]; then
        if [ "$VERSION_ID" = "9.6" ] || [ "$VERSION_ID" = "8.10" ]; then
            echo "Supported OS: rocky $VERSION_ID"
            SYSTEM=rocky
            return 0
        else
            echo "Unsupported rocky version: $VERSION_ID"
            exit 1
        fi
    else
        echo "Unsupported OS: $ID $VERSION_ID"
        exit 1
    fi
}

ConfigUbuntuNetwork() {
    cat > /etc/netplan/50-cloud-init.yaml << EOF
network:
    version: 2
    ethernets:
        eth0:
            addresses:
                - ${PRI_IP4}/${PRI_PREFIX}
EOF

    for EIP in $ALL_PUB_EIP4s; do
        echo "                - ${EIP}/32" >> /etc/netplan/50-cloud-init.yaml
    done

    cat >> /etc/netplan/50-cloud-init.yaml << EOF
            nameservers:
                addresses:
                - ${NAME_SERVER1}
                - ${NAME_SERVER2}
EOF
    # Default route
    cat >> /etc/netplan/50-cloud-init.yaml << EOF
            routes:
                - to: default
                  via: ${PRI_GW4}
                  from: ${DEFAULT_PUB_EIP4}
EOF
}

ConfigCentOSNetwork() {
    rm -f /etc/sysconfig/network-scripts/ifcfg-eth0*
    cat << EOF > /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
BOOTPROTO=static
ONBOOT=yes
IPADDR=${PRI_IP4}
PREFIX=${PRI_PREFIX}
EOF

index=0

    for EIP in $ALL_PUB_EIP4s; do
        cat << EOF > /etc/sysconfig/network-scripts/ifcfg-eth0:$index
DEVICE=eth0:$index
BOOTPROTO=static
ONBOOT=yes
IPADDR=${EIP}
PREFIX=32
EOF
        index=$((index+1))
    done

    # Default route
    cat << EOF > /etc/sysconfig/network-scripts/route-eth0
default via ${PRI_GW4} dev eth0 src ${DEFAULT_PUB_EIP4}
EOF
    # Disable DHCP on eth2
    cat << EOF > /etc/sysconfig/network-scripts/ifcfg-eth2
DEVICE=eth2
BOOTPROTO=none
ONBOOT=yes
EOF
}

ConfigDebianNetwork() {
    cat > /etc/network/interfaces.d/50-cloud-init << EOF

auto lo
iface lo inet loopback
    dns-nameservers ${NAME_SERVER1} ${NAME_SERVER2}

auto eth0
iface eth0 inet static
    address ${PRI_IP4}/${PRI_PREFIX}

auto eth0:0
iface eth0:0 inet static
    address ${DEFAULT_PUB_EIP4}/32
    up ip route add default via ${PRI_GW4} dev eth0 src ${DEFAULT_PUB_EIP4}
    down ip route del default via ${PRI_GW4} dev eth0 src ${DEFAULT_PUB_EIP4}
EOF

    index=1

    for EIP in $ALL_PUB_EIP4s; do
        if [ "$EIP" = "$DEFAULT_PUB_EIP4" ]; then
            continue
        fi
        cat >> /etc/network/interfaces.d/50-cloud-init << EOF

auto eth0:$index
iface eth0:$index inet static
    address ${EIP}/32
EOF
       index=$((index+1))
    done
}

FetchMetaData() {
    pri_macs=$($META_CURL $META_URL/ | sed 's/\///g')

    nic_count=$(echo "$pri_macs" | wc -w | tr -d ' ')
    if [ "$nic_count" -ne 1 ]; then
        echo "[ERR] Expected exactly one nic, got $nic_count: $pri_macs" >&2
        exit 4
    fi

    PRI_IP4=$($META_CURL $META_URL/$pri_macs/primary-ip-address)
    pri_subnet_cidr=$($META_CURL $META_URL/$pri_macs/subnet-cidr-block)
    PRI_PREFIX=$(echo "$pri_subnet_cidr" | cut -d'/' -f2)
    PRI_GW4=$($META_CURL $META_URL/$pri_macs/gateway)
    DEFAULT_PUB_EIP4=$($META_CURL $META_URL/$pri_macs/public-ipv4)
    ALL_PUB_EIP4s=$($META_CURL $META_URL/$pri_macs/public-ipv4s | sed 's/\[//;s/\]//;s/"//g;s/,/ /g')

    if [ -z "$pri_macs" ] || [ -z "$PRI_IP4" ] || [ -z "$pri_subnet_cidr" ] || [ -z "$PRI_PREFIX" ] || [ -z "$PRI_GW4" ] || [ -z "$DEFAULT_PUB_EIP4" ] || [ -z "$ALL_PUB_EIP4s" ]; then
        echo "[ERR] Missing metadata, check EC2 metadata service." >&2
        exit 3
    fi

    echo "  Private MacAddr:     $pri_macs"
    echo "  Private IPv4:        $PRI_IP4"
    echo "  Private Prefix:      $PRI_PREFIX"
    echo "  Private GWv4:        $PRI_GW4"
    echo "  ALl Public IPv4:     $ALL_PUB_EIP4s"
    echo "  Default Public IPv4: $DEFAULT_PUB_EIP4"
}

ConfigNetwork() {
    # Disable RPF (Reverse Path Filtering)
    if ! grep -q "net.ipv4.conf.all.rp_filter=0" /etc/sysctl.conf; then
        echo "net.ipv4.conf.all.rp_filter=0" | tee -a /etc/sysctl.conf > /dev/null
        sysctl -p /etc/sysctl.conf
    fi

    # Disable cloud-init network configuration
    echo "network: {config: disabled}" > /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg

    if [ "$SYSTEM" = "ubuntu" ]; then
        ConfigUbuntuNetwork
    elif [ "$SYSTEM" = "centos" ]; then
        ConfigCentOSNetwork
    elif [ "$SYSTEM" = "debian" ]; then
        if [ "$VERSION_ID" = "11" ] || [ "$VERSION_ID" = "10" ]; then
            ConfigDebianNetwork
        elif [ "$VERSION_ID" = "12" ]; then
            ConfigUbuntuNetwork
        else
            echo "Unsupported Debian version: $VERSION_ID"
            exit 1
        fi
    elif [ "$SYSTEM" = "rocky" ]; then
        ConfigCentOSNetwork
    else
        echo "Unsupported OS for network config: $SYSTEM"
        exit 1
    fi
}

echo "1. Check OS..."
CheckSupportedOS

echo

echo "2. FetchMetaData..."
FetchMetaData

echo

echo "3. Configuring networks..."
ConfigNetwork

echo

echo
echo "Done."

sync

```

{% endcode %}

4. 重启实例\
   调用 API 重启实例以使配置生效。
5. 添加更多 IP（可选）\
   如需绑定更多 IP，重复以下步骤：\
   \- 绑定 IP\
   \- 运行命令\
   \- 重启实例
   {% endtab %}
   {% endtabs %}

#### 3. 故障排查

**3.1 配置未生效**

**原因：** 未重启实例\
**解决方案：** 重启实例

**3.2 配置失败**

* 确保所有 IP 均为 Bypass 模式
* 确认操作系统在支持列表内