Hi Alan, Thank you for your comments.
2012/5/31 Alan Robertson <al...@unix.sh>: > It's straightforward to determine if an IP address is link-local or not - > for an already configured address. > > 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state > UP qlen 1000 > link/ether 94:db:c9:3f:7c:20 brd ff:ff:ff:ff:ff:ff > inet 10.10.10.30/24 brd 10.10.10.255 scope global eth1 > inet6 fe80::96db:c9ff:fe3f:7c20/64 scope link > valid_lft forever preferred_lft forever > > This works uniformly for both ipv4 and ipv6 addresses (quite nice!) It's an interesting idea, but I don't think we need to care about IPv4 link-local addresses because users can configure using the same manner as a "regular" IP address. (and it's used very rarely) In the case of IPv6 link-local addresses it is almost always a wrong configuration if nic is missing (the socket API mandate it) so we want to check it. > > However, for addresses which are not yet up (which is unfortunately what > you're concerned with), ipv6 link-local addresses take the form > fe80:: -- followed by 64-bits of MAC addresses (48 bit > MACs are padded out) > > http://en.wikipedia.org/wiki/Link-local_address > > MAC addresses never begin with 4 bytes of zeros, so the regular expression > to match this is pretty straightforward. This isn't a bad approximation > (but could easily be made better): Yes, you are right. Matching to 'fe80::' should be pretty easy and good enough. Why I could not think of such a simple idea :) > > islinklocal() { > if > echo $1 | grep -i '^fe80::[^:]*:[^:]*:[^:]*:[^:]*$' >/dev/null We should also accept 'fe80::1'. Anyway I will look into this way. Thanks, -- Keisuke MORI _______________________________________________________ Linux-HA-Dev: Linux-HA-Dev@lists.linux-ha.org http://lists.linux-ha.org/mailman/listinfo/linux-ha-dev Home Page: http://linux-ha.org/
