IPv6 RA always contains an implicit default route via
the link-local address of the source of RA. This forces
the guest to install a route via isolated network, which
may disturb the guest's networking in case of multiple interfaces.
More info in 013427e6e7.
The validity of this route is controlled by "default [route] lifetime"
field of RA. If the lifetime is set to 0 seconds, then no route
is installed by receiver.
dnsmasq 2.67+ supports "ra-param=<interface>,<RA interval>,<default
lifetime>" option. We pass "ra-param=*,0,0"
(here, RA_interval=0 means default) to disable default gateway in RA
for isolated networks.
Originally, only a host name was used to associate a
DHCPv6 request with a specific IPv6 address. Further testing
demonstrates that this is an unreliable method and, instead,
a client-id or DUID needs to be used. According to DHCPv6
standards, this id can be a duid-LLT, duid-LL, or duid-UUID
even though dnsmasq will accept almost any text string.
Although validity checking of a specified string makes sure it is
hexadecimal notation with bytes separated by colons, there is no
rigorous check to make sure it meets the standard.
Documentation and schemas have been updated.
Signed-off-by: Gene Czarcinski <gene@czarc.net>
Signed-off-by: Laine Stump <laine@laine.org>
