Support IPv6 Prefix Delegation

[topranks]

Many ISPs provide IPv6 addressing through DHCPv6 with prefix-delegation as described in RFC3633. The original ifupdown supports requesting IPv6 prefix delegation on an interface through the request_prefix toggle under an inet6 dhcp interface definition.

Enabling that option causes ifupdown to pass the '-P' flag to the dhclient process that is triggered.

ifupdown2 does not support the "request_prefix" option, and thus cannot be used in scenarios requiring it. I'm not 100% sure if there is interest in supporting it, or having equivalent functionality with original ifupdown in general? It doesn't seem like it would be too tricky to add but I am unsure of the status of this project overall and within Nvidia, there has been no release in 3 years?