T2x - No IPv6 DHCP

[GeorgSchwarz]

We are currently introducing IPv6 for our customers. Due to technical circumstances, we are required to use IPv6 DHCP and not stateless autoconfig.

We started our tests with a T26P, a T28P and a T46G. All FW versions are latest v72 from the website. For the T28 it is currently 2.72.0.1 While the 46G obtained an IPv6-address from the DHCPv6 server the T26 and T28 did not get an IPv6-Address.
We tried the tests with IPv4&IPv6 and IPv6 addressing mode only. In both settings the T26/28 did not get an IP-Address from the DHCPv6 Server When we captured all traffic coming from the phones (mirror port), the T26/T28s did not send one single packet when in IPv6-only mode However the display has a blinking message Obtaining IP-Address The phones were reset to factory defaults before, and the IPv6 only DHCP-mode was set via the web interface, while the phone still had an IPv4 address that it obtained via DHCPv4 (and we ensured that there was no autoprovisioning or whatsoever interfering) As a matter of fact, we cannot provide a syslog trace or the configuration, because the phone is unreachable….

Have you guys at Yealink already heard about that behavior of T2-Series?
If it is confirmed, when will a firmware be available that solves that issue?