Replace BusyBox udhcpc6 with OpenWrt's odhcp6c for improved DHCPv6
functionality and better integration with Router Advertisements (RA).
The primary motivation is support for a common ISP deployment scenario
where IPv6 addresses are assigned via SLAAC (from Router Advertisements)
and DHCPv6 is used in stateless/information-only mode to provide DNS
servers and other configuration options. This hybrid RA+DHCPv6 setup is
standard practice for many ISPs but was not supported by udhcpc6, which
treats RA and DHCPv6 as separate, non-integrated mechanisms.
Additional benefits of odhcp6c:
- Better IPv6 Prefix Delegation (IA-PD) support with proper handling
of delegated prefix lifetimes and renewal
- Native integration of RA-provided configuration (DNS servers, routes,
addresses) with DHCPv6-provided options
- Support for stateless DHCPv6 via information-only mode
To verify stateless DHCPv6 integration with SLAAC addresses - the ISP
scenario that motivated this migration, a new test case has been added.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Let's drop the leading IETF or Infix prefixes from tests. Initially the
idea was to mimnic the YANG models, but it's difficult to navigate and
does not provide any real benefit to developers or end-users.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>