☰

对于 IPv6，preferred_lft 默认如何设置？

tag-icon • tag-icon networking ipv6 hetzner
对于 IPv6，preferred_lft 默认如何设置？

在 Hetzner Cloud 上使用 Debian 和 Ubuntu 时，我注意到默认 IPv6 的 preferred_lft 为 0 秒。因此它已“弃用”，这会导致在添加另一个 inet6 时出现问题，因为未弃用的 ipv6 优先。

root@debian-2gb-nbg1-1:~# ip -6 a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 state UNKNOWN qlen 1000
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
    inet6 2a01:4f8:c2c:6daa::1/64 scope global deprecated
       valid_lft forever preferred_lft 0sec
    inet6 fe80::9400:ff:fe2d:6848/64 scope link
       valid_lft forever preferred_lft forever

配置如下：

root@debian-2gb-nbg1-1:~# cat /etc/network/interfaces.d/50-cloud-init.cfg
# This file is generated from information provided by
# the datasource.  Changes to it will not persist across an instance.
# To disable cloud-init's network configuration capabilities, write a file
# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
# network: {config: disabled}
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp
    dns-nameservers 213.133.99.99 213.133.98.98 213.133.100.100

auto eth0:0
iface eth0:0 inet6 static
    address 2a01:4f8:c2c:6daa::1/64
    gateway fe80::1
    post-up route add -net :: netmask 0 gw fe80::1%eth0 || true
    pre-down route del -net :: netmask 0 gw fe80::1%eth0 || true

这是从哪里来0sec的？

答案1

解决方案是不使用 IPv6 虚拟接口：

root@debian-2gb-nbg1-1:~# cat /etc/network/interfaces.d/50-cloud-init.cfg
# This file is generated from information provided by
# the datasource.  Changes to it will not persist across an instance.
# To disable cloud-init's network configuration capabilities, write a file
# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
# network: {config: disabled}
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp
    dns-nameservers 213.133.99.99 213.133.98.98 213.133.100.100
iface eth0 inet6 static
    address 2a01:4f8:c2c:6daa::1/64
    gateway fe80::1
    post-up route add -net :: netmask 0 gw fe80::1%eth0 || true
    pre-down route del -net :: netmask 0 gw fe80::1%eth0 || true

这样就不会出现 preferred_lft 问题，并且 IPv6 也不会被标记为已弃用。

root@debian-2gb-nbg1-1:~# ip -6 a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 state UNKNOWN qlen 1000
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
    inet6 2a01:4f8:c2c:6daa::1/64 scope global
       valid_lft forever preferred_lft forever
    inet6 fe80::9400:ff:fe2d:6848/64 scope link
       valid_lft forever preferred_lft forever

相关内容