I suppose I took/take the view that it *is*, in a sense, being used for
documentation.
The network is a training network, isolated from the Internet, and used
for demonstration purposes. It's a good way to engrave the doco prefix
in the students' minds. It also allows all the slides, exercises and
other documentation to use the documentation prefix and yet directly
match the demonstration network.
ULA prefixes have little internal logic and are hard to remember. Not a
problem in production, but just another barrier in a training
environment. "2001:db8::/32" is very easy to remember (I guess that's
the point) and easy to add easy-to-use subnets into.
However, I do appreciate that it's a bit of an edge case. In my training
I specifically draw the students' attention to this fact.
Thanks, K.
Hi
Then I won't use this ipv6 address 2001:db8:cafe:1111::12 for test
Acutually, I have one in eth0 when I run ifconfig -a
inet6 addr: fe80::20c:29ff:fe3c:92a1/64 Scope:Link
but I also can't ping it
ping6 fe80::20c:29ff:fe3c:92a1
connect: Invalid argument
but ping6 ::1 is fine
ping6 ::1
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=0 ttl=64 time=7.18 ms
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.050 ms
inet6 addr: fe80::20c:29ff:fe3c:92a1/64 Scope:Link
This is a link level address, only valid on one interface. So you need to look
at which interface it is attached to in the ifconfig output.
ping6 fe80::20c:29ff:fe3c:92a1
connect: Invalid argument
ping6 wants the interface name for link-scope addresses, because on some
hardware setups, the same MAC is used for all interfaces, which means that
each interface has the same link-scope address. So to disambiguate it,
you have to feed it the interface name so it knows which link to use.
On my laptop, I currently have:
wlan0 Link encap:Ethernet HWaddr 00:24:D6:53:C5:BA
inet6 addr: fe80::224:d6ff:fe53:c5ba/64 Scope:Link
% ping fe80::224:d6ff:fe53:c5ba%wlan0
ping6 fe80::224:d6ff:fe53:c5ba%wlan0
PING fe80::224:d6ff:fe53:c5ba%wlan0(fe80::224:d6ff:fe53:c5ba) 56 data bytes
64 bytes from fe80::224:d6ff:fe53:c5ba: icmp_seq=1 ttl=64 time=0.072 ms
64 bytes from fe80::224:d6ff:fe53:c5ba: icmp_seq=2 ttl=255 time=0.081 ms
64 bytes from fe80::224:d6ff:fe53:c5ba: icmp_seq=3 ttl=255 time=0.090 ms
^C
--- fe80::224:d6ff:fe53:c5ba%wlan0 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 1999ms
rtt min/avg/max/mdev = 0.072/0.081/0.090/0.007 ms
Hi
Thank you. I try your way. the ipv6 address is on eth0 interface.
I try to run ping6 the fe80::20c:29ff:fe3c:92a1%eth0
lt is same problem!
Any idea?
Thank you
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 00:0c:29:3c:92:a1 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.12/24 brd 192.168.1.255 scope global eth0
inet6 fe80::20c:29ff:fe3c:92a1/64 scope link tentative
valid_lft forever preferred_lft forever
# ping6 fe80::20c:29ff:fe3c:92a1
connect: Invalid argument
# ping6 fe80::20c:29ff:fe3c:92a1%eth0
connect: Invalid argument
Try ping6 -I eth0 fe80::20c:29ff:fe3c:92a1
Hi
What is this meaning?
ping6 -l eth0 fe80::20c:29ff:fe3c:92a1
ping: bad preload value, should be 1..65536
Thank you
That was a capital "i" not a lower case "L". man ping6
Hi Jason
Thank you. Can I know what is wrong?
ping6 -I eth0 fe80::20c:29ff:fe3c:92a1
connect: Cannot assign requested address
Thank you
Maybe duplicate address detection? Are you statically assigning this address? Have you checked your kernel log?