vr的机器默认用IPv6访问了

# curl -v https://www.google.com/
* About to connect() to www.google.com port 443 (#0)
* Trying 2404:6800:4005:c00::68... connected
* Connected to www.google.com (2404:6800:4005:c00::68) port 443 (#0)

wget https://www.google.com/
--2013-02-19 09:55:20-- https://www.google.com/
Resolving www.google.com... 2404:6800:4005:c00::67, 74.125.128.147, 74.125.128.104, ...
Connecting to www.google.com|2404:6800:4005:c00::67|:443... connected.


另外由于我是用vr作为自己的代理服务器(ssh tunnel)，gmail里的recent activity显示的都是IPv6地址

我不是很确定curl这个优先使用IPv6的行为是受哪个配置控制。我甚至不确定这台机器上的curl是不是一直以来都是这样。ubuntu 10.04

但是我可以确定的是，gmail的recent activity在不久之前，还是显示IPv4地址

另外我也不是很清楚mail.google.com何时启用了AAAA记录



我担心的是，vr是不是在没有通知用户的情况下，修改了用户的vps的操作系统配置

下面这个文件，我近期并没有做任何修改，但是显示mtime是上个月


# stat /etc/sysctl.conf
File: `/etc/sysctl.conf'
Size: 2272 Blocks: 8 IO Block: 4096 regular file
Device: ca03h/51715d Inode: 47035 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2013-02-19 09:38:36.000000000 -0800
Modify: 2013-01-09 20:59:35.000000000 -0800
Change: 2013-01-09 20:59:35.000000000 -0800

# tail /etc/sysctl.conf
# Log Martian Packets
#net.ipv4.conf.all.log_martians = 1
net.ipv6.conf.all.accept_ra=0
net.ipv6.conf.all.autocOnf=0
net.ipv6.conf.default.accept_ra=0
net.ipv6.conf.default.autocOnf=0
net.ipv6.conf.eth0.accept_ra=0
net.ipv6.conf.eth0.autocOnf=0
net.ipv6.conf.lo.accept_ra=0
net.ipv6.conf.lo.autocOnf=0