Am Donnerstag, den 02.06.2011, 12:16 -0400 schrieb Bernd Stramm:
On Thu, 2 Jun 2011 17:07:47 +0100 "Richard W.M. Jones" rjones@redhat.com wrote:
On Thu, Jun 02, 2011 at 06:00:44PM +0200, Björn Persson wrote:
Daniel P. Berrange wrote:
On Thu, Jun 02, 2011 at 04:40:10PM +0100, Richard W.M. Jones wrote:
The Linux machines on my LAN appear to have acquired IPv6 addresses, eg:
$ ip addr show eth0 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
link/ether 00:e0:81:74:02:28 brd ff:ff:ff:ff:ff:ff inet 192.168.0.128/24 brd 192.168.0.255 scope global eth0 inet6 fe80::2e0:81ff:fe74:228/64 scope link valid_lft forever preferred_lft forever
but pinging them gives me strange errors:
$ ping6 fe80::2e0:81ff:fe74:228/64 unknown host $ ping6 fe80::2e0:81ff:fe74:228 connect: Invalid argument $ ping6 fe80::2e0:81ff:fe74 connect: Invalid argument
Anything with an fe80:: prefix is a link local address, which is only unique within the scope of a single LAN segment. Thus if you want to send traffic to such addresses, you need to specify the NIC to send the traffic out from. The vast majority of apps using sockets have no way to let you do this.
Ping6 has a way though:
$ ping6 -I eth0 fe80::200:24ff:fec9:2e0c PING fe80::200:24ff:fec9:2e0c(fe80::200:24ff:fec9:2e0c) from fe80::21e:8cff:fecf:cde5 eth0: 56 data bytes 64 bytes from fe80::200:24ff:fec9:2e0c: icmp_seq=1 ttl=64 time=1.69 ms 64 bytes from fe80::200:24ff:fec9:2e0c: icmp_seq=2 ttl=64 time=0.263 ms
But that's not so useful if no other programs can use these addresses. Is there a way to assign "proper" addresses? Just run radvd and configure it with a random prefix?
Instead of random, you may want to use a Unique Local Address prefix, following http://www.ripe.net/lir-services/resource-management/ipv6/ipv6-address-types
I brought this up some time ago: Assigning ULA instead of LL would be somewhat more user friendly: https://bugzilla.gnome.org/show_bug.cgi?id=615063 https://bugzilla.redhat.com/show_bug.cgi?id=581579
In my eyes just assigning a LL adress is not very user friendly.
Rich.
-- Bernd Stramm bernd.stramm@gmail.com