path: root/Documentation/networking
diff options
authorErik Kline <ek@google.com>2014-10-28 18:11:14 +0900
committerDavid S. Miller <davem@davemloft.net>2014-10-29 15:11:36 -0400
commit7fd2561e4ebdd070ebba6d3326c4c5b13942323f (patch)
tree0705e64d0da12c0194a17f64445f30336159d7b7 /Documentation/networking
parent8b243a61940d2ca3c3a370e551b88d47a09ede0c (diff)
net: ipv6: Add a sysctl to make optimistic addresses useful candidates
Add a sysctl that causes an interface's optimistic addresses to be considered equivalent to other non-deprecated addresses for source address selection purposes. Preferred addresses will still take precedence over optimistic addresses, subject to other ranking in the source address selection algorithm. This is useful where different interfaces are connected to different networks from different ISPs (e.g., a cell network and a home wifi network). The current behaviour complies with RFC 3484/6724, and it makes sense if the host has only one interface, or has multiple interfaces on the same network (same or cooperating administrative domain(s), but not in the multiple distinct networks case. For example, if a mobile device has an IPv6 address on an LTE network and then connects to IPv6-enabled wifi, while the wifi IPv6 address is undergoing DAD, IPv6 connections will try use the wifi default route with the LTE IPv6 address, and will get stuck until they time out. Also, because optimistic nodes can receive frames, issue an RTM_NEWADDR as soon as DAD starts (with the IFA_F_OPTIMSTIC flag appropriately set). A second RTM_NEWADDR is sent if DAD completes (the address flags have changed), otherwise an RTM_DELADDR is sent. Also: add an entry in ip-sysctl.txt for optimistic_dad. Signed-off-by: Erik Kline <ek@google.com> Acked-by: Lorenzo Colitti <lorenzo@google.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/networking')
1 files changed, 13 insertions, 0 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 9028b879a97b..368e3251c553 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -1460,6 +1460,19 @@ suppress_frag_ndisc - INTEGER
1 - (default) discard fragmented neighbor discovery packets
0 - allow fragmented neighbor discovery packets
+optimistic_dad - BOOLEAN
+ Whether to perform Optimistic Duplicate Address Detection (RFC 4429).
+ 0: disabled (default)
+ 1: enabled
+use_optimistic - BOOLEAN
+ If enabled, do not classify optimistic addresses as deprecated during
+ source address selection. Preferred addresses will still be chosen
+ before optimistic addresses, subject to other ranking in the source
+ address selection algorithm.
+ 0: disabled (default)
+ 1: enabled
ratelimit - INTEGER
Limit the maximal rates for sending ICMPv6 packets.

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