android_kernel_oneplus_msm8998/net
Philip Downey df2cf4a78e IGMP: Inhibit reports for local multicast groups
The range of addresses between 224.0.0.0 and 224.0.0.255 inclusive, is
reserved for the use of routing protocols and other low-level topology
discovery or maintenance protocols, such as gateway discovery and
group membership reporting.  Multicast routers should not forward any
multicast datagram with destination addresses in this range,
regardless of its TTL.

Currently, IGMP reports are generated for this reserved range of
addresses even though a router will ignore this information since it
has no purpose.  However, the presence of reserved group addresses in
an IGMP membership report uses up network bandwidth and can also
obscure addresses of interest when inspecting membership reports using
packet inspection or debug messages.

Although the RFCs for the various version of IGMP (e.g.RFC 3376 for
v3) do not specify that the reserved addresses be excluded from
membership reports, it should do no harm in doing so.  In particular
there should be no adverse effect in any IGMP snooping functionality
since 224.0.0.x is specifically excluded as per RFC 4541 (IGMP and MLD
Snooping Switches Considerations) section 2.1.2. Data Forwarding
Rules:

    2) Packets with a destination IP (DIP) address in the 224.0.0.X
       range which are not IGMP must be forwarded on all ports.

IGMP reports for local multicast groups can now be optionally
inhibited by means of a system control variable (by setting the value
to zero) e.g.:
    echo 0 > /proc/sys/net/ipv4/igmp_link_local_mcast_reports

To retain backwards compatibility the previous behaviour is retained
by default on system boot or reverted by setting the value back to
non-zero e.g.:
    echo 1 >  /proc/sys/net/ipv4/igmp_link_local_mcast_reports

Signed-off-by: Philip Downey <pdowney@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-28 13:28:47 -07:00
..
6lowpan 6lowpan: move module_init into core functionality 2015-08-11 22:05:36 +02:00
9p 9p: ensure err is initialized to 0 in p9_client_read/write 2015-08-22 21:35:02 -04:00
802
8021q net: 8021q: convert to using IFF_NO_QUEUE 2015-08-18 11:55:06 -07:00
appletalk
atm br2684: Remove unnecessary formatting macros b1 and bs 2015-07-31 15:25:52 -07:00
ax25 NET: AX.25: Stop heartbeat timer on disconnect. 2015-07-15 15:59:58 -07:00
batman-adv batman-adv: beautify supported routing algorithm list 2015-08-25 00:12:24 +02:00
bluetooth Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next 2015-08-17 15:41:21 -07:00
bridge bridge: fdb: rearrange net_bridge_fdb_entry 2015-08-27 16:38:52 -07:00
caif net: caif: convert to using IFF_NO_QUEUE 2015-08-18 11:55:07 -07:00
can
ceph
core Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-08-27 21:45:31 -07:00
dcb
dccp tcp: fix recv with flags MSG_WAITALL | MSG_PEEK 2015-07-27 01:06:53 -07:00
decnet
dns_resolver
dsa net: dsa: Allow multi hop routes to be expressed 2015-08-18 14:17:21 -07:00
ethernet net: ethernet: Fix double word "the the" in eth.c 2015-08-09 22:53:00 -07:00
hsr net: hsr: convert to using IFF_NO_QUEUE 2015-08-18 11:55:07 -07:00
ieee802154 net: 6lowpan: convert to using IFF_NO_QUEUE 2015-08-18 11:55:06 -07:00
ipv4 IGMP: Inhibit reports for local multicast groups 2015-08-28 13:28:47 -07:00
ipv6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-08-27 21:45:31 -07:00
ipx
irda
iucv
key net: Fix RCU splat in af_key 2015-08-24 14:48:10 -07:00
l2tp
lapb
llc tcp: fix recv with flags MSG_WAITALL | MSG_PEEK 2015-07-27 01:06:53 -07:00
mac80211 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-08-21 11:44:04 -07:00
mac802154 ieee802154: add ack request default handling 2015-08-10 20:43:06 +02:00
mpls lwt: Add cfg argument to build_state 2015-08-24 10:34:40 -07:00
netfilter netfilter: connlabels: Export setting connlabel length 2015-08-27 11:40:43 -07:00
netlabel
netlink netlink: mmap: fix tx type check 2015-08-23 16:04:46 -07:00
netrom
nfc nfc: netlink: Add capability to reply to vendor_cmd with data 2015-08-20 22:00:11 +02:00
openvswitch openvswitch: Include ip6_fib.h. 2015-08-27 16:35:51 -07:00
packet packet: add extended BPF fanout mode 2015-08-17 14:22:48 -07:00
phonet
rds RDS: remove superfluous from rds_ib_alloc_fmr() 2015-08-25 16:28:11 -07:00
rfkill Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next 2015-08-17 15:41:21 -07:00
rose
rxrpc
sched Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-08-27 21:45:31 -07:00
sctp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-08-27 21:45:31 -07:00
sunrpc NFS client bugfixes for Linux 4.2 2015-07-28 09:37:44 -07:00
switchdev net: switchdev: support static FDB addresses 2015-08-11 12:03:19 -07:00
tipc tipc: fix stale link problem during synchronization 2015-08-23 16:14:45 -07:00
unix
vmw_vsock
wimax net:wimax: Fix doucble word "the the" in networking.xml 2015-08-09 22:43:52 -07:00
wireless nl80211: Allow setting multicast rate on OCB interfaces 2015-08-14 17:49:48 +02:00
x25
xfrm xfrm: Add oif to dst lookups 2015-08-11 12:41:35 +02:00
compat.c
Kconfig lwtunnel: infrastructure for handling light weight tunnels like mpls 2015-07-21 10:39:03 -07:00
Makefile
socket.c
sysctl_net.c