1
0
Fork 0
remarkable-linux/net/ipv4
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
..
netfilter Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-08-21 06:09:05 +02:00
Kconfig geneve: Consolidate Geneve functionality in single module. 2015-08-27 15:42:48 -07:00
Makefile geneve: Consolidate Geneve functionality in single module. 2015-08-27 15:42:48 -07:00
af_inet.c inet: Move VRF table lookup to inlined function 2015-08-17 15:58:57 -07:00
ah4.c ah4: Fix error return in ah_input(). 2015-08-25 13:38:50 -07:00
arp.c net: Fix up inet_addr_type checks 2015-08-13 22:43:21 -07:00
cipso_ipv4.c ipv4: coding style: comparison for inequality with NULL 2015-04-03 12:11:15 -04:00
datagram.c net: Set sk_txhash from a random number 2015-07-29 22:44:04 -07:00
devinet.c net/ipv4: suppress NETDEV_UP notification on address lifetime update 2015-07-28 23:38:13 -07:00
esp4.c esp4: Switch to new AEAD interface 2015-05-28 11:23:20 +08:00
fib_frontend.c net: Add routes to the table associated with the device 2015-08-13 22:43:21 -07:00
fib_lookup.h ipv4: consider TOS in fib_select_default 2015-07-24 22:46:11 -07:00
fib_rules.c net: ipv4 sysctl option to ignore routes when nexthop link is down 2015-06-24 02:15:54 -07:00
fib_semantics.c lwt: Add cfg argument to build_state 2015-08-24 10:34:40 -07:00
fib_trie.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-08-21 11:44:04 -07:00
fou.c fou: Do WARN_ON_ONCE in gue_gro_receive for bad proto callbacks 2015-08-23 15:59:56 -07:00
gre_demux.c gre: Remove support for sharing GRE protocol hook. 2015-08-10 14:03:54 -07:00
gre_offload.c ipv4: coding style: comparison for inequality with NULL 2015-04-03 12:11:15 -04:00
icmp.c vrf: vrf_master_ifindex_rcu is not always called with rcu read lock 2015-08-19 22:13:20 -07:00
igmp.c IGMP: Inhibit reports for local multicast groups 2015-08-28 13:28:47 -07:00
inet_connection_sock.c inet: fix potential deadlock in reqsk_queue_unlink() 2015-08-13 22:46:22 -07:00
inet_diag.c net: inet_diag: always export IPV6_V6ONLY sockopt for listening sockets 2015-07-10 23:25:24 -07:00
inet_fragment.c inet: frags: remove INET_FRAG_EVICTED and use list_evictor for the test 2015-07-26 21:00:15 -07:00
inet_hashtables.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-07-23 00:41:16 -07:00
inet_lro.c lro: remove dead code 2013-12-29 16:34:25 -05:00
inet_timewait_sock.c inet: inet_twsk_deschedule factorization 2015-07-09 15:12:20 -07:00
inetpeer.c inet: remove dead inetpeer sequence code 2014-09-08 16:42:42 -07:00
ip_forward.c ip: reject too-big defragmented DF-skb when forwarding 2015-05-25 00:08:48 -04:00
ip_fragment.c net: frags: Add VRF device index to cache and lookup 2015-08-13 22:43:21 -07:00
ip_gre.c tunnel: introduce udp_tun_rx_dst() 2015-08-27 15:42:47 -07:00
ip_input.c dst: Metadata destinations 2015-07-21 10:39:05 -07:00
ip_options.c ipv4: coding style: comparison for inequality with NULL 2015-04-03 12:11:15 -04:00
ip_output.c net: Use VRF index for oif in ip_send_unicast_reply 2015-08-13 22:43:21 -07:00
ip_sockglue.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-06-24 02:58:51 -07:00
ip_tunnel.c ip_gre: Add support to collect tunnel metadata. 2015-08-10 14:03:54 -07:00
ip_tunnel_core.c lwt: Add cfg argument to build_state 2015-08-24 10:34:40 -07:00
ip_vti.c ip_vti/ip6_vti: Preserve skb->mark after rcv_cb call 2015-05-28 06:23:32 +02:00
ipcomp.c ipv4: coding style: comparison for equality with NULL 2015-04-03 12:11:15 -04:00
ipconfig.c net: ipv4: increase dhcp inter device timeout 2015-08-12 16:40:22 -07:00
ipip.c ip_gre: Add support to collect tunnel metadata. 2015-08-10 14:03:54 -07:00
ipmr.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
netfilter.c netfilter: don't use module_init/exit in core IPV4 code 2015-06-16 14:12:34 -04:00
ping.c ipv6: Nonlocal bind 2015-07-09 21:09:10 -07:00
proc.c net: track success and failure of TCP PMTU probing 2015-07-21 22:36:33 -07:00
protocol.c net: Export inet_offloads and inet6_offloads 2014-09-19 17:15:31 -04:00
raw.c Merge branch 'for-davem' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-13 18:18:05 -04:00
route.c route: move lwtunnel state to dst_entry 2015-08-20 15:42:36 -07:00
syncookies.c tcp: get_cookie_sock() consolidation 2015-06-07 15:19:52 -07:00
sysctl_net_ipv4.c IGMP: Inhibit reports for local multicast groups 2015-08-28 13:28:47 -07:00
tcp.c tcp: fix slow start after idle vs TSO/GSO 2015-08-25 11:22:50 -07:00
tcp_bic.c tcp: add tcp_in_slow_start helper 2015-07-09 14:22:52 -07:00
tcp_cdg.c tcp: do not slow start when cwnd equals ssthresh 2015-07-09 14:22:52 -07:00
tcp_cong.c tcp: do not slow start when cwnd equals ssthresh 2015-07-09 14:22:52 -07:00
tcp_cubic.c tcp: add tcp_in_slow_start helper 2015-07-09 14:22:52 -07:00
tcp_dctcp.c net: tcp: dctcp_update_alpha() fixes. 2015-06-10 23:28:33 -07:00
tcp_diag.c sock_diag: implement a get_info handler for inet 2015-06-15 19:49:22 -07:00
tcp_fastopen.c tcp: Do not call tcp_fastopen_reset_cipher from interrupt context 2015-06-23 02:38:10 -07:00
tcp_highspeed.c tcp: add tcp_in_slow_start helper 2015-07-09 14:22:52 -07:00
tcp_htcp.c tcp: add tcp_in_slow_start helper 2015-07-09 14:22:52 -07:00
tcp_hybla.c tcp: do not slow start when cwnd equals ssthresh 2015-07-09 14:22:52 -07:00
tcp_illinois.c tcp: add tcp_in_slow_start helper 2015-07-09 14:22:52 -07:00
tcp_input.c tcp: refine pacing rate determination 2015-08-25 11:33:54 -07:00
tcp_ipv4.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-08-13 16:23:11 -07:00
tcp_lp.c tcp: remove in_flight parameter from cong_avoid() methods 2014-05-03 19:23:07 -04:00
tcp_memcontrol.c memcg: cleanup static keys decrement 2015-02-12 18:54:10 -08:00
tcp_metrics.c tcp: add tcp_in_slow_start helper 2015-07-09 14:22:52 -07:00
tcp_minisocks.c inet: inet_twsk_deschedule factorization 2015-07-09 15:12:20 -07:00
tcp_offload.c tcp: reserve tcp_skb_mss() to tcp stack 2015-06-11 16:33:10 -07:00
tcp_output.c tcp: fix slow start after idle vs TSO/GSO 2015-08-25 11:22:50 -07:00
tcp_probe.c tcp: whitespace fixes 2014-09-01 18:12:45 -07:00
tcp_scalable.c tcp: add tcp_in_slow_start helper 2015-07-09 14:22:52 -07:00
tcp_timer.c tcp: do not export tcp_init_xmit_timers() 2015-07-09 21:44:38 -07:00
tcp_vegas.c tcp: add tcp_in_slow_start helper 2015-07-09 14:22:52 -07:00
tcp_vegas.h tcp: prepare CC get_info() access from getsockopt() 2015-04-29 17:10:38 -04:00
tcp_veno.c tcp: add tcp_in_slow_start helper 2015-07-09 14:22:52 -07:00
tcp_westwood.c tcp_westwood: fix tcp_westwood_info() 2015-05-05 19:50:09 -04:00
tcp_yeah.c tcp: stretch ACK fixes prep 2015-01-28 22:18:37 -08:00
tunnel4.c net: Convert printks to pr_<level> 2012-03-11 23:42:51 -07:00
udp.c udp: Handle VRF device in sendmsg 2015-08-13 22:43:20 -07:00
udp_diag.c sock_diag: specify info_size per inet protocol 2015-06-15 19:49:22 -07:00
udp_impl.h net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
udp_offload.c ipv4: coding style: comparison for inequality with NULL 2015-04-03 12:11:15 -04:00
udp_tunnel.c tunnel: introduce udp_tun_rx_dst() 2015-08-27 15:42:47 -07:00
udplite.c net: Eliminate no_check from protosw 2014-05-23 16:28:53 -04:00
xfrm4_input.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
xfrm4_mode_beet.c ipv4: ERROR: code indent should use tabs where possible 2013-12-26 13:43:21 -05:00
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c ipv4: hash net ptr into fragmentation bucket selection 2015-03-25 14:07:04 -04:00
xfrm4_output.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
xfrm4_policy.c xfrm: Use VRF master index if output device is enslaved 2015-08-25 11:25:09 -07:00
xfrm4_protocol.c xfrm4: Remove duplicate semicolon 2014-06-30 07:49:47 +02:00
xfrm4_state.c inet: make no_pmtu_disc per namespace and kill ipv4_config 2013-12-18 16:58:20 -05:00
xfrm4_tunnel.c sit: add IPv4 over IPv4 support 2013-05-31 17:19:05 -07:00