pppd: Disable Duplicate Address Detection for IPv6 peer address

IPv6 link-local addresses are negotiated via IPV6CP and therefore are
unique and not duplicate. Doing additional Duplicate Address Detection
is redundant and not needed, so disable it.

Signed-off-by: Pali Rohár <pali@kernel.org>

diff --git a/pppd/sys-linux.c b/pppd/sys-linux.c
index a7508fe3989601278c667bf3fb150a12afcb70c8..ca0db844018a9c9e31dac56df39e5a8c5939fa3a 100644 (file)
--- a/pppd/sys-linux.c
+++ b/pppd/sys-linux.c
@@ -2885,7 +2885,7 @@ static int append_peer_ipv6_address(unsigned int iface, struct in6_addr *local_a
     ifa = NLMSG_DATA(nlmsg);
     ifa->ifa_family = AF_INET6;
     ifa->ifa_prefixlen = 128;
-    ifa->ifa_flags = IFA_F_PERMANENT;
+    ifa->ifa_flags = IFA_F_NODAD | IFA_F_PERMANENT;
     ifa->ifa_scope = RT_SCOPE_LINK;
     ifa->ifa_index = iface;