Re: How to identify 6to4 and 6in4 tunnels

On 01/28/2014 03:39 PM, zhuyj wrote:

On 01/28/2014 03:32 PM, zhuyj wrote:

quoted

On 01/27/2014 08:59 PM, Nicolas Dichtel wrote:

quoted

Le 27/01/2014 11:39, zhuyj a écrit :

quoted

Hi, Maintainers

In our scene, we will create the 6in4/6to4 tunnel firstly and need 
to check the
tunnel type, secondly, we will configure the ip address on it. So, 
Could we have
any way to get the actual tunnel for 6in4 and 6to4 from current 
linux version?

Both 6in4 and 6to4 have the same protocol “IPPROTO_IPV6” in Linux 
kernel. The
only difference is the ip address on the tunnel. Can we distinguish 
them in
Linux kernel?

Just check the prefix, like it is done in check_6rd().


Regards,
Nicolas

Hi, Nicolas
Thanks for your reply. Maybe I can configure 6to4 tunnel by the 
following commands:

 ip tunnel add tun6to4 mode sit remote any local 1.202.252.122 ttl 64
 ip link set dev tun6to4 up
 ip -6 addr add 2002:01ca:fc7a::0012:0225:2122/128 dev tun6to4
 ip -6 route add 2000::/3 via ::192.88.99.1 dev tun6to4 metric 1

But the kernel can not identify the tunnel is 6to4 tunnel or 6in4 
tunnel immediately. After the packets travel through this tunnel, the 
kernel can identify the type of the tunnel by check_6rd.

Is it right?

Best Regards!
Zhu Yanjun

Hi, David

I want to identify sit interface 6to4 or 6in4 with the following parameters.

include/uapi/linux/if_tunnel.h
...
struct ip_tunnel_parm {
         char                    name[IFNAMSIZ];
         int                     link;
         __be16                  i_flags;             <---------I want 
to use this variable to identify the type of sit interface. Can I?
         __be16                  o_flags;
         __be32                  i_key;
         __be32                  o_key;
         struct iphdr            iph;
};
...

Please comment on this ? Thanks a lot.

Best Regards!
Zhu Yanjun