Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Obvious way (just setting up 6to4 tunnel and pinging) fails because ip command seems to be read-only on my VPS: can't change any networking-related settings.

So I try using raw sockets:

root@  printf '\x06\x00\x00\x00\x00\x40\x3a\x40''\x20\x02\x4e\x8a\x64\x19\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01''\x2a\x00\x14\x50\x40\x0c\x0c\x03\x00\x00\x00\x00\x00\x00\x00\x93''\x80\x00\x17\x21\x07\x71\x00\x01\xb7\x2e\x6b\x50\xbf\xd0\x07\x00\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x20\x21\x22\x23\x24\x25\x26\x27\x28\x29\x2a\x2b\x2c\x2d\x2e\x2f\x30\x31\x32\x33\x34\x35\x36\x37' | socat - ip-sendto: | hd

\x2a\x00\x14\x50\x40\x0c\x0c\x03\x00\x00\x00\x00\x00\x00\x00\x93 is
\x20\x02\x4e\x8a\x64\x19\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01 is 2002:

tcpdump shows this:

18:31:26.982253 IP > IP6 2002:4e8a:6419::1 > 2a00:1450:400c:c03::93: ICMP6, echo request, seq 1, length 64

But no replies.

Am I doing everything correctly, but protocol 41 is filtered or there is mistake somewhere? Maybe there is some other user-space way to check if 6to4 is working?

share|improve this question
most likely you can't do many things on your VPS - it might be supporting very small subset of a 'real' kernel features. As for tunnels - why they should filter ipv4 traffic? – Serge Oct 2 '12 at 20:43
I don't know, just because... To prevent any unusual things. – Vi. Oct 2 '12 at 21:05

You must log in to answer this question.

Browse other questions tagged .