virtualbox虚拟机--虚拟机的网络

墨蓝 2024-02-18 20:01 15阅读 0赞

今天要测试IP多宿主（ip multihoming），即host和guest的两个网卡分别接，host ping guest的ipv6不通。解决过程如下：

命令输出：

# ip addr
    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
        link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
        inet 127.0.0.1/8 scope host lo
           valid_lft forever preferred_lft forever
        inet6 ::1/128 scope host
           valid_lft forever preferred_lft forever
    2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
        link/ether 08:00:27:33:7e:04 brd ff:ff:ff:ff:ff:ff
        inet 172.18.34.202/26 brd 172.18.34.255 scope global dynamic eth0
           valid_lft 172228sec preferred_lft 172228sec
        inet6 fe80::a00:27ff:fe33:7e04/64 scope link tentative dadfailed
           valid_lft forever preferred_lft forever
    3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
        link/ether 08:00:27:53:77:09 brd ff:ff:ff:ff:ff:ff
        inet 192.168.57.12/24 brd 192.168.57.255 scope global eth1
           valid_lft forever preferred_lft forever
        inet6 fe80::a00:27ff:fe53:7709/64 scope link tentative dadfailed
           valid_lft forever preferred_lft forever

看到tentative dadfailed, 原来dad的意思是Duplicate Address Detection，默认值是1也就是拒绝DAD。见： [https://blog.tankywoo.com/linux/2013/09/27/ipv6-dadfailed-problem.html][https_blog.tankywoo.com_linux_2013_09_27_ipv6-dadfailed-problem.html]

执行完发现确实是：

# sysctl -a | grep accept_dad
    net.ipv6.conf.all.accept_dad = 1
    net.ipv6.conf.default.accept_dad = 1
    net.ipv6.conf.eth0.accept_dad = 1
    net.ipv6.conf.eth1.accept_dad = 1
    net.ipv6.conf.lo.accept_dad = -1

将用于host和guest通信的（HOST-ONLY）接口accept\_dad设置成0，并重启网络服务：

sysctl -w net.ipv6.conf.eth1.accept_dad=0
    sysctl -w net.ipv6.conf.eth2.accept_dad=0
    service network restart

打印网络接口信息可以看到eth2和eth3的tentative dad消失：

# ip addr
    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
        link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
        inet 127.0.0.1/8 scope host lo
           valid_lft forever preferred_lft forever
        inet6 ::1/128 scope host
           valid_lft forever preferred_lft forever
    2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
        link/ether 08:00:27:33:7e:04 brd ff:ff:ff:ff:ff:ff
        inet 172.18.34.202/26 brd 172.18.34.255 scope global dynamic eth0
           valid_lft 172803sec preferred_lft 172803sec
        inet6 fe80::a00:27ff:fe33:7e04/64 scope link tentative dadfailed
           valid_lft forever preferred_lft forever
    3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
        link/ether 08:00:27:53:77:09 brd ff:ff:ff:ff:ff:ff
        inet 192.168.57.12/24 brd 192.168.57.255 scope global eth1
           valid_lft forever preferred_lft forever
        inet6 fe80::a00:27ff:fe53:7709/64 scope link   注意到tentative dadfailed没有了。
           valid_lft forever preferred_lft forever

从host ping guest，首先通过ipconfig查看virtualbox的虚拟网卡VirtualBox Host-Only Network \#2和VirtualBox Host-Only Network的IPV6地址后面的接口标号（百分号后面）。因为我的guest网卡配置这两个host的虚拟网卡分别对应eth1和eth2（与virtualbox的配置界面中mac地址对应。eth0做网桥用），所以结果：

ping ipv6\_address\_eth1%15  
ping ipv6\_address\_eth2%16

[https_blog.tankywoo.com_linux_2013_09_27_ipv6-dadfailed-problem.html]: https://blog.tankywoo.com/linux/2013/09/27/ipv6-dadfailed-problem.html