proxmoxの虚拟机无法ping通外网的解决办法

使用proxmox创建的虚拟机，无法访问外网的解决办法：

1、配置/etc/network/interfaces文件

添加如下信息：

auto vmbr2
iface vmbr2 inet static
        address 10.0.0.254/24
        bridge-ports none
        bridge-stp off
        bridge-fd 0
        post-up echo 1 > /proc/sys/net/ipv4/ip_forward
        post-up iptables -t nat -A POSTROUTING -s '10.0.0.0/24' -o vmbr0 -j MASQUERADE
        post-down iptables -t nat -D POSTROUTING -s '10.0.0.0/24' -o vmbr0 -j MASQUERADE
        post-up iptables -t nat -A PREROUTING -i vmbr0 -p tcp --dport 8888 -j DNAT --to 10.0.0.102:8888
        post-down iptables -t nat -D PREROUTING -i vmbr0 -p tcp --dport 8888 -j DNAT --to 10.0.0.102:8888
        post-up iptables -t nat -A PREROUTING -i vmbr0 -p tcp --dport 3389 -j DNAT --to 10.0.0.102:3389
        post-down iptables -t nat -D PREROUTING -i vmbr0 -p tcp --dport 3389 -j DNAT --to 10.0.0.102:3389
        post-up iptables -t nat -A PREROUTING -i vmbr0 -p tcp --dport 10022 -j DNAT --to 10.0.0.102:22
        post-down iptables -t nat -D PREROUTING -i vmbr0 -p tcp --dport 10022 -j DNAT --to 10.0.0.102:22
        post-up iptables -t nat -A PREROUTING -i vmbr0 -p tcp --dport 80 -j DNAT --to 10.0.0.102:80
        post-down iptables -t nat -D PREROUTING -i vmbr0 -p tcp --dport 80 -j DNAT --to 10.0.0.102:80
        post-up iptables -t nat -A PREROUTING -i vmbr0 -p tcp --dport 443 -j DNAT --to 10.0.0.102:443
        post-down iptables -t nat -D PREROUTING -i vmbr0 -p tcp --dport 443 -j DNAT --to 10.0.0.102:443
以下为新增，增加回流，这样就可以在nat通过公网IP访问服务：
        post-up iptables -t nat -A PREROUTING -s 10.0.0.0/24 -d 公网/32 -p tcp -m tcp --dport 80 -j DNAT --to-destination 10.0.0.102
        post-up iptables -t nat -A POSTROUTING -s 10.0.0.0/24 -d 10.0.0.0/24 -j SNAT --to-source 10.0.0.254
        post-down iptables -t nat -A PREROUTING -s 10.0.0.0/24 -d 公网/32 -p tcp -m tcp --dport 80 -j DNAT --to-destination 10.0.0.102
        post-down iptables -t nat -A POSTROUTING -s 10.0.0.0/24 -d 10.0.0.102 -j SNAT --to-source 10.0.0.254
说明：
        PREROUTING -s 私网网段 -d 公网IP -j DNAT –to-destination 私网服务器地址
        POSTROUTING -s 私网网段 -d 私网服务器地址 -j SNAT –to-source 私网网关

配置后，文件内容大致如下：

auto lo
iface lo inet loopback

iface enp1s0 inet manual

auto vmbr0
iface vmbr0 inet static
        address 公网IP地址/32
        gateway 100.64.35.133
        bridge-ports enp1s0
        bridge-stp off
        bridge-fd 0

iface vmbr0 inet6 static
        address IPV6/64
        gateway IPV6网关

auto vmbr2
iface vmbr2 inet static
        address 10.0.0.254/24
        bridge-ports none
        bridge-stp off
        bridge-fd 0
        post-up echo 1 > /proc/sys/net/ipv4/ip_forward
        post-up iptables -t nat -A POSTROUTING -s '10.0.0.0/24' -o vmbr0 -j MASQUERADE
        post-down iptables -t nat -D POSTROUTING -s '10.0.0.0/24' -o vmbr0 -j MASQUERADE
        post-up iptables -t nat -A PREROUTING -i vmbr0 -p tcp --dport 8888 -j DNAT --to 10.0.0.102:8888
        post-down iptables -t nat -D PREROUTING -i vmbr0 -p tcp --dport 8888 -j DNAT --to 10.0.0.102:8888
        post-up iptables -t nat -A PREROUTING -i vmbr0 -p tcp --dport 3389 -j DNAT --to 10.0.0.102:3389
        post-down iptables -t nat -D PREROUTING -i vmbr0 -p tcp --dport 3389 -j DNAT --to 10.0.0.102:3389
        post-up iptables -t nat -A PREROUTING -i vmbr0 -p tcp --dport 10022 -j DNAT --to 10.0.0.102:22
        post-down iptables -t nat -D PREROUTING -i vmbr0 -p tcp --dport 10022 -j DNAT --to 10.0.0.102:22
        post-up iptables -t nat -A PREROUTING -i vmbr0 -p tcp --dport 80 -j DNAT --to 10.0.0.102:80
        post-down iptables -t nat -D PREROUTING -i vmbr0 -p tcp --dport 80 -j DNAT --to 10.0.0.102:80
        post-up iptables -t nat -A PREROUTING -i vmbr0 -p tcp --dport 443 -j DNAT --to 10.0.0.102:443
        post-down iptables -t nat -D PREROUTING -i vmbr0 -p tcp --dport 443 -j DNAT --to 10.0.0.102:443
        post-up iptables -t nat -A PREROUTING -s 10.0.0.0/24 -d 公网/32 -p tcp -m tcp --dport 80 -j DNAT --to-destination 10.0.0.102
        post-up iptables -t nat -A POSTROUTING -s 10.0.0.0/24 -d 10.0.0.0/24 -j SNAT --to-source 10.0.0.254
        post-down iptables -t nat -A PREROUTING -s 10.0.0.0/24 -d 公网/32 -p tcp -m tcp --dport 80 -j DNAT --to-destination 10.0.0.102
        post-down iptables -t nat -A POSTROUTING -s 10.0.0.0/24 -d 10.0.0.102 -j SNAT --to-source 10.0.0.254

重启网络配置:

service networking restart

2、在proxmox管理界面配置虚拟机网络属性

选择vmb2

3、在虚拟机中配置网络属性：

测试：