Hi Team, Had a doubt regarding Optimistic DAD implementation in linux kernel. The RFC of Optimistic DAD states: "Section 3.3 A router SHOULD NOT configure an Optimistic Address." To check the same there is a condition in kernel code wherein we check if ipv6.devconf_all is set. Now, my query is that we are checking if forwarding is enabled on all interfaces, then we consider the system to be a router. But even if forwarding is enabled from few interfaces(not all) isn't the system behaving like a router? void addrconf_add_linklocal<https://elixir.bootlin.com/linux/latest/ident/addrconf_add_linklocal>(struct inet6_dev<https://elixir.bootlin.com/linux/latest/ident/inet6_dev> *idev<https://elixir.bootlin.com/linux/latest/ident/idev>, const struct in6_addr<https://elixir.bootlin.com/linux/latest/ident/in6_addr> *addr, u32<https://elixir.bootlin.com/linux/latest/ident/u32> flags) { . . . . #ifdef<https://elixir.bootlin.com/linux/latest/ident/ifdef> CONFIG_IPV6_OPTIMISTIC_DAD if ((dev_net<https://elixir.bootlin.com/linux/latest/ident/dev_net>(idev<https://elixir.bootlin.com/linux/latest/ident/idev>->dev)->ipv6.devconf_all->optimistic_dad || idev<https://elixir.bootlin.com/linux/latest/ident/idev>->cnf.optimistic_dad) && !dev_net<https://elixir.bootlin.com/linux/latest/ident/dev_net>(idev<https://elixir.bootlin.com/linux/latest/ident/idev>->dev)->ipv6.devconf_all->forwarding<https://elixir.bootlin.com/linux/latest/ident/forwarding>) cfg<https://elixir.bootlin.com/linux/latest/ident/cfg>.ifa_flags |= IFA_F_OPTIMISTIC<https://elixir.bootlin.com/linux/latest/ident/IFA_F_OPTIMISTIC>; #endif . . . . } Thanks Chinmay