pimd/TODO - quagga - Gitiles

 # $QuaggaId: $Format:%an, %ai, %h$ $

 T1 DONE Implement debug command
    test pim receive join

 T2 DONE Implement debug command
    test pim receive prune

 T3 DONE Per-interface Downstream (S,G) state machine
    (RFC 4601 4.5.3. Receiving (S,G) Join/Prune Messages)

 T4 DONE Upstream (S,G) state machine
    (RFC 4601 4.5.7. Sending (S,G) Join/Prune Messages)

 T5 DONE Verify Data Packet Forwarding Rules
    RFC 4601 4.2.  Data Packet Forwarding Rules
    RFC 4601 4.8.2.  PIM-SSM-Only Routers

    Additionally, the Packet forwarding rules of Section 4.2 can be
    simplified in a PIM-SSM-only router:

      iif is the incoming interface of the packet.
      oiflist = NULL
      if (iif == RPF_interface(S) AND UpstreamJPState(S,G) == Joined) {
        oiflist = inherited_olist(S,G)
      } else if (iif is in inherited_olist(S,G)) {
        send Assert(S,G) on iif
      }
      oiflist = oiflist (-) iif
      forward packet on all interfaces in oiflist

    Macro:
      inherited_olist(S,G) =
        joins(S,G) (+) pim_include(S,G) (-) lost_assert(S,G)

 T6 DONE Implement (S,G) Assert state machine (RFC 4601, section 4.6.1).
    Changes in pim_ifchannel.ifassert_winner should trigger
    pim_upstream_update_join_desired().
    Depends on TODO T27.
    Depends on TODO T33.
    See also CAVEAT C7.
    See also: RFC 4601 4.5.7. Sending (S,G) Join/Prune Messages
     Transitions from Joined State
      RPF'(S,G) changes due to an Assert

    http://www.hep.ucl.ac.uk/~ytl/multi-cast/pim-dm_01.html:

      The PIM Assert mechanism is used to shutoff duplicate flows onto
      the same multiaccess network. Routers detect this condiction when
      they receive an (S,G) packet via a multi-access interface that is
      in the (S,G) OIL. This causes the routers to send Assert
      Messages.

    Note that neighbors will not accept Join/Prune or Assert messages
    from a router unless they have first heard a Hello message from that
    router.  Thus, if a router needs to send a Join/Prune or Assert
    message on an interface on which it has not yet sent a Hello message
    with the currently configured IP address, then it MUST immediately
    send the relevant Hello message without waiting for the Hello Timer
    to expire, followed by the Join/Prune or Assert message.

 T7 DONE Implement hello option: LAN Prune Delay

 T8 DONE Implement J/P_Override_Interval(I)
    Depends on TODO T7.
    See pim_ifchannel.c, pim_ifchannel_prune(), jp_override_interval.

 T9 DONE Detect change in IGMPv3 RPF interface/next-hop for S and update.
    channel_oil vif index accordingly ?
    Beware accidentaly adding looped MFC entries (IIF=OIF).

 T10 DONE React to (S,G) join directed to another upstream address. See
     also:

     RFC 4601: 4.5.7.  Sending (S,G) Join/Prune Messages

     If a router wishes to propagate a Join(S,G) upstream, it must also
     watch for messages on its upstream interface from other routers on
     that subnet, and these may modify its behavior.  If it sees a
     Join(S,G) to the correct upstream neighbor, it should suppress its
     own Join(S,G).  If it sees a Prune(S,G), Prune(S,G,rpt), or
     Prune(*,G) to the correct upstream neighbor towards S, it should
     be prepared to override that prune by scheduling a Join(S,G) to be
     sent almost immediately.

 T11 DONE Review protocol modifications for SSM
     (RFC 4601 4.8.1.  Protocol Modifications for SSM Destination
     Addresses)

 T12 DONE Review updates of RPF entries.
     FIXME pim_upstream.c send_join():
     Currently only one upstream state is affected by detection of RPF change.
     RPF change should affect all upstream states sharing the RPF cache.

 T13 DONE Check that RFC macros using S,G,RPF_interface(S) are actually
     implemented with this strategy:
     rpf_ifch=find_ifch(up->rpf->interface).
     See pim_rpf.c pim_rpf_find_rpf_addr() for a correct example.

     $ grep -i macro pimd/*.c
     pimd/pim_iface.c:  RFC 4601: 4.1.6.  State Summarization Macros
     pimd/pim_ifchannel.c:    RFC 4601: 4.6.5.  Assert State Macros
     pimd/pim_ifchannel.c:  RFC 4601: 4.1.6.  State Summarization Macros
     pimd/pim_ifchannel.c:  RFC 4601: 4.1.6.  State Summarization Macros
     pimd/pim_ifchannel.c:  RFC 4601: 4.6.5.  Assert State Macros
     pimd/pim_ifchannel.c:  Macro:
     pimd/pim_rpf.c:  RFC 4601: 4.1.6.  State Summarization Macros

 T14 DONE Send Assert(S,G) on iif as response to WRONGVIF kernel upcall.
     See pim_mroute.c mroute_msg().

 T15 DONE Interface command to statically join (S,G).
     interface eth0
      ip igmp join-group 239.1.1.1 source 1.1.1.1

 T16 DONE RPF'(S,G) lookup is not working for S reachable with default route.
     See "RPF'(S,G) not found" in pim_rpf_update() from pim_rpf.c.
     Zebra daemon RIB is not reflecting changes in kernel routes
     accurately?

 T17 DONE Prevent CLI from creating bogus interfaces.
     Example:
     conf t
      interface xxx

 T18 Consider reliable pim solution (refresh reduction)
     A Reliable Transport Mechanism for PIM
     http://tools.ietf.org/wg/pim/draft-ietf-pim-port/
     PORT=PIM-Over-Reliable-Transport

 T19 DONE Fix self as neighbor
     See mailing list post:
     http://lists.gnu.org/archive/html/qpimd-users/2009-04/msg00000.html

 T20 DONE Fix debug message: "pim_neighbor_update: internal error:
     trying to replace same prefix list"
     See mailing list post:
     http://lists.gnu.org/archive/html/qpimd-users/2009-04/msg00000.html

 T21 DONE Clean-up PIM/IGMP interface mismatch debugging
     See option PIM_CHECK_RECV_IFINDEX_SANITY in pimd/Makefile.am
     See mailing list post:
     http://lists.nongnu.org/archive/html/qpimd-users/2009-04/msg00003.html

 T22 DONE IGMP must be protected against adding looped MFC entries
     created by both source and receiver attached to the same
     interface.

 T23 DONE libzebra crash after zclient_lookup_nexthop.
     See mailing list post:
     http://lists.nongnu.org/archive/html/qpimd-users/2009-04/msg00008.html

 T24 DONE zserv may return recursive routes:
      - nexthop type is set to ZEBRA_NEXTHOP_IPV4
      - ifindex is not reported
      - calls expecting ifindex (fib_lookup_if_vif_index) are disrupted
     See also this mailing list post:
     [PATCH 21/21] Link detect and recursive routes
     http://www.gossamer-threads.com/lists/quagga/dev/17564

 T25 DONE Zclient nexthop lookup missing OSPF route to 1.1.1.1/32
     See also:
     pim_zlookup.c zclient_lookup_nexthop misses OSPF 1.1.1.1/32
     zebra/zebra_vty.c show_ip_route_addr_cmd hits OSPF 1.1.1.1/32

 T26 DONE Zebra daemon is marking recursive static route as inactive.

     FIXED: zebra daemon was incorrectly marking recursive routes
     pointing to kernel routes as inactive:
       zebra/zebra_rib.c nexthop_active_ipv4:
         -- Original:
 	  else if (CHECK_FLAG (rib->flags, ZEBRA_FLAG_INTERNAL))
         -- Fixed:
 	  else if (CHECK_FLAG (rib->flags, ZEBRA_FLAG_INTERNAL) ||
 		   match->type == ZEBRA_ROUTE_KERNEL)

     Old problem description:

     This prevents rib_match_ipv4 from returning its nexthop:
     client: pim_zlookup.c zclient_read_nexthop
     server: zebra/zserv.c zsend_ipv4_nexthop_lookup_v2 -> rib_match_ipv4

     Kernel route is injected into zebra in zebra_rib.c rib_add_ipv4
     Examples:
     rt_netlink.c:726: rib_add_ipv4 (ZEBRA_ROUTE_KERNEL, flags, &p, gate, src, index, table, metric, 0);
     rt_netlink.c:864: rib_add_ipv4 (ZEBRA_ROUTE_KERNEL, 0, &p, gate, src, index, table, 0, 0);

     This patch didn't fix the issue:
     [PATCH 21/21] Link detect and recursive routes
     http://www.gossamer-threads.com/lists/quagga/dev/17564

     See the example below for the route 2.2.2.2.

 bash# route add -host 1.1.1.1 gw 127.0.0.1
 bash# route add -host 2.2.2.2 gw 1.1.1.1
 bash# netstat -nvr
 Kernel IP routing table
 Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
 2.2.2.2         1.1.1.1         255.255.255.255 UGH       0 0          0 lo
 1.1.1.1         127.0.0.1       255.255.255.255 UGH       0 0          0 lo
 192.168.0.0     0.0.0.0         255.255.255.0   U         0 0          0 eth0
 0.0.0.0         192.168.0.2     0.0.0.0         UG        0 0          0 eth0
 bash#

 zebra# sh ip route
 Codes: K - kernel route, C - connected, S - static, R - RIP, O - OSPF,
        I - ISIS, B - BGP, > - selected route, * - FIB route

 K>* 0.0.0.0/0 via 192.168.0.2, eth0
 K>* 1.1.1.1/32 via 127.0.0.1, lo
 K * 2.2.2.2/32 via 1.1.1.1, lo inactive
 C>* 127.0.0.0/8 is directly connected, lo
 C>* 192.168.0.0/24 is directly connected, eth0

 quagga-pimd-router# sh ip route 1.1.1.1
 Address         NextHop         Interface Metric Preference
 1.1.1.1         127.0.0.1       lo             0          0
 quagga-pimd-router#
 quagga-pimd-router# sh ip route 2.2.2.2
 Address         NextHop         Interface Metric Preference
 2.2.2.2         192.168.0.2     eth0           0          0
 quagga-pimd-router#

 T27 DONE Implement debug command
     test pim receive assert
     See also TODO T6: (S,G) Assert state machine.

 T28 DONE Bad IPv4 address family=02 in Join/Prune dump
     Reported by Andrew Lunn <andrew.lunn@ascom.ch>

     # 58-byte pim v2 Join/Prune dump
     # ------------------------------
     # IPv4 address family=02 is wrong, correct IPv4 address family is 01
     # See http://www.iana.org/assignments/address-family-numbers
     #
     c8XX YY03 : ip src 200.xx.yy.3
     e000 000d : ip dst 224.0.0.13
     9404 0000 : ip router alert option 148.4.0.0
     2300 ab13 : pimv2,type=3 res=00 checksum=ab13
     0200      : upstream family=02, encoding=00
     c8XX YY08 : upstream 200.xx.yy.8
     0001 00d2 : res=00 groups=01 holdtime=00d2
     0200 0020 : group family=02, encoding=00, res=00, mask_len=20
     ef01 0101 : group address 239.1.1.1
     0001 0000 : joined=0001 pruned=0000
     0200 0020 : source family=02, encoding=00, res=00, mask_len=20
     0101 0101 : source address 1.1.1.1

 T29 DONE Reset interface PIM-hello-sent counter when primary address changes
     See pim_ifp->pim_ifstat_hello_sent

     RFC 4601: 4.3.1.  Sending Hello Messages

     Thus, if a router needs to send a Join/Prune or Assert message on
     an interface on which it has not yet sent a Hello message with the
     currently configured IP address, then it MUST immediately send the
     relevant Hello message without waiting for the Hello Timer to
     expire, followed by the Join/Prune or Assert message.

 T30 DONE Run interface DR election when primary address changes
     Reported by Andrew Lunn <andrew.lunn@ascom.ch>
     See pim_if_dr_election().

 T31 If an interface changes one of its secondary IP addresses, a Hello
     message with an updated Address_List option and a non-zero
     HoldTime should be sent immediately.
     See also detect_secondary_address_change
     See also CAVEAT C15.
     See also RFC 4601: 4.3.1.  Sending Hello Messages

 T32 FIXED Detection of interface primary address changes may fail when
     there are multiple addresses.
     See also CAVEAT C14.

     pim_find_primary_addr() should return interface primary address
     from connected list. Currently it returns the first address.

     Zebra daemon "show int" is able to keep the primary address as
     first address.

 T33 DONE Implement debug command: test pim receive upcall
     See also TODO T6: (S,G) Assert state machine.

 T34 DONE assert_action_a1

 T35 DONE Review macros depending on interface I.

     See also: grep ,I\) pimd/*.c

     For the case (S,G,I) check if I is either
     1) interface attached to this per-interface S,G state (don't think so)
     or
     2) an arbitrary interface (most probably)

     For the arbitrary interface case (2), consider representing
     interface ifp as its primary address (struct in_addr ifaddr).  The
     benefit is in_addr does not need to be dereferenced, so it does
     not demand protection against crashes.

 T36 DONE React to zebra daemon link-detect up/down notification.
     pim_ifp->primary_address is managed by detect_primary_address_change()
     depending on to ifp->connected (managed by zebra_interface_address_read()).

 T37 DONE Review list of variables which may affect pim_upstream.c
     pim_upstream_evaluate_join_desired().
     Call pim_upstream_update_join_desired() accordingly.

     See the order of invokation:
       pim_if_dr_election(ifp);
       pim_if_update_join_desired(pim_ifp); /* depends on DR */
       pim_if_update_could_assert(ifp); /* depends on DR */
       pim_if_update_my_assert_metric(ifp); /* depends on could_assert */

     join_desired depends on:
       pim_ifp->primary_address
       pim_ifp->pim_dr_addr
       ch->ifassert_winner_metric
       ch->ifassert_winner
       ch->local_ifmembership
       ch->ifjoin_state
       ch->upstream->rpf.source_nexthop.mrib_metric_preference
       ch->upstream->rpf.source_nexthop.mrib_route_metric
       ch->upstream->rpf.source_nexthop.interface

 T38 DONE Detect change in AssertTrackingDesired(S,G,I)

     See the order of invokation:
       dr_election: none
       update_join_desired: depends on DR
       update_tracking_desired: depends on DR, join_desired

     AssertTrackingDesired(S,G,I) depends on:
       pim_ifp->primary_address
       pim_ifp->pim_dr_addr
       ch->local_ifmembership
       ch->ifassert_winner
       ch->ifjoin_state
       ch->upstream->rpf.source_nexthop.interface
       PIM_UPSTREAM_FLAG_TEST_DR_JOIN_DESIRED(ch->upstream->flags)

 T39 DONE AssertTrackingDesired: flags is not matching evaluation

     # show ip pim assert-internal
     CA:   CouldAssert
     ECA:  Evaluate CouldAssert
     ATD:  AssertTrackingDesired
     eATD: Evaluate AssertTrackingDesired

     Interface Address         Source          Group           CA  eCA ATD eATD
     eth0      192.168.1.100   1.1.1.1         239.1.1.1       no  no  no  yes
     #

 T40 Lightweight MLDv2
     http://tools.ietf.org/html/draft-ietf-mboned-lightweight-igmpv3-mldv2-05
     http://www.ietf.org/internet-drafts/draft-ietf-mboned-lightweight-igmpv3-mldv2-05.txt
     http://www.ietf.org/html.charters/mboned-charter.html

 T41 DONE ssmping support

     See also:
       http://www.venaas.no/multicast/ssmping/
       draft-ietf-mboned-ssmping-07
       http://tools.ietf.org/html/draft-ietf-mboned-ssmping-07

     Example:

     debug ssmpingd

     conf t
      ip ssmpingd 1.1.1.1

     show ip ssmpingd

 T42 Static igmp join fails when loading config at boot time

     ! Wrong behavior seen at boot time:
     !
     2010/02/22 08:59:00 PIM: igmp_source_forward_start: ignoring request for
     looped MFC entry (S,G)=(3.3.3.3,239.3.3.3): igmp_sock=12 oif=eth0 vif_index=2

     ! Correct behavior seen later:
     !
     2010/02/22 09:03:16 PIM: igmp_source_forward_start: ignoring request for
     looped MFC entry (S,G)=(2.2.2.2,239.2.2.2): igmp_sock=17 oif=lo vif_index=1

     ! To see the wrong message at boot:
     !
     debug igmp trace
     !
     interface lo
      ip igmp
      ip igmp join 239.2.2.2 2.2.2.2
      ip igmp join 239.3.3.3 3.3.3.3
     !

     ! Interfaces indexes:
     Interface Address         ifi Vif  PktsIn PktsOut    BytesIn   BytesOut
     eth0      200.202.112.3     2   2       0       0          0          0
     lo        127.0.0.1         1   1       0       0          0          0

 T43 PIM Neighbor Reduction
     https://datatracker.ietf.org/doc/draft-wijnands-pim-neighbor-reduction/

     "In a transit LAN (no directly connected source or receiver), many
     of the PIM procedures don't apply. (...) This proposal describes
     a procedure to reduce the amount of neighbors established over a
     transit LAN."

 T44 Single Stream Multicast Fast Reroute (SMFR) Method
     https://datatracker.ietf.org/doc/draft-liu-pim-single-stream-multicast-frr/

     "This document proposes an IP multicast fast convergence method
     based on differentiating primary and backup PIM join."

 T45 RFC5384 - The Join Attribute Format
     "This document describes a modification of the Join message that
     allows a node to associate attributes with a particular tree."

 T46 PIM Multi-Topology ID (MT-ID) Join-Attribute
     http://tools.ietf.org/html/draft-cai-pim-mtid-00
     Depends on T45.

     "This draft introduces a new type of PIM Join Attribute used to
     encode the identity of the topology PIM uses for RPF."

 -x-
	# $QuaggaId: $Format:%an, %ai, %h$ $

	T1 DONE Implement debug command
	test pim receive join

	T2 DONE Implement debug command
	test pim receive prune

	T3 DONE Per-interface Downstream (S,G) state machine
	(RFC 4601 4.5.3. Receiving (S,G) Join/Prune Messages)

	T4 DONE Upstream (S,G) state machine
	(RFC 4601 4.5.7. Sending (S,G) Join/Prune Messages)

	T5 DONE Verify Data Packet Forwarding Rules
	RFC 4601 4.2. Data Packet Forwarding Rules
	RFC 4601 4.8.2. PIM-SSM-Only Routers

	Additionally, the Packet forwarding rules of Section 4.2 can be
	simplified in a PIM-SSM-only router:

	iif is the incoming interface of the packet.
	oiflist = NULL
	if (iif == RPF_interface(S) AND UpstreamJPState(S,G) == Joined) {
	oiflist = inherited_olist(S,G)
	} else if (iif is in inherited_olist(S,G)) {
	send Assert(S,G) on iif
	}
	oiflist = oiflist (-) iif
	forward packet on all interfaces in oiflist

	Macro:
	inherited_olist(S,G) =
	joins(S,G) (+) pim_include(S,G) (-) lost_assert(S,G)

	T6 DONE Implement (S,G) Assert state machine (RFC 4601, section 4.6.1).
	Changes in pim_ifchannel.ifassert_winner should trigger
	pim_upstream_update_join_desired().
	Depends on TODO T27.
	Depends on TODO T33.
	See also CAVEAT C7.
	See also: RFC 4601 4.5.7. Sending (S,G) Join/Prune Messages
	Transitions from Joined State
	RPF'(S,G) changes due to an Assert

	http://www.hep.ucl.ac.uk/~ytl/multi-cast/pim-dm_01.html:

	The PIM Assert mechanism is used to shutoff duplicate flows onto
	the same multiaccess network. Routers detect this condiction when
	they receive an (S,G) packet via a multi-access interface that is
	in the (S,G) OIL. This causes the routers to send Assert
	Messages.

	Note that neighbors will not accept Join/Prune or Assert messages
	from a router unless they have first heard a Hello message from that
	router. Thus, if a router needs to send a Join/Prune or Assert
	message on an interface on which it has not yet sent a Hello message
	with the currently configured IP address, then it MUST immediately
	send the relevant Hello message without waiting for the Hello Timer
	to expire, followed by the Join/Prune or Assert message.

	T7 DONE Implement hello option: LAN Prune Delay

	T8 DONE Implement J/P_Override_Interval(I)
	Depends on TODO T7.
	See pim_ifchannel.c, pim_ifchannel_prune(), jp_override_interval.

	T9 DONE Detect change in IGMPv3 RPF interface/next-hop for S and update.
	channel_oil vif index accordingly ?
	Beware accidentaly adding looped MFC entries (IIF=OIF).

	T10 DONE React to (S,G) join directed to another upstream address. See
	also:

	RFC 4601: 4.5.7. Sending (S,G) Join/Prune Messages

	If a router wishes to propagate a Join(S,G) upstream, it must also
	watch for messages on its upstream interface from other routers on
	that subnet, and these may modify its behavior. If it sees a
	Join(S,G) to the correct upstream neighbor, it should suppress its
	own Join(S,G). If it sees a Prune(S,G), Prune(S,G,rpt), or
	Prune(*,G) to the correct upstream neighbor towards S, it should
	be prepared to override that prune by scheduling a Join(S,G) to be
	sent almost immediately.

	T11 DONE Review protocol modifications for SSM
	(RFC 4601 4.8.1. Protocol Modifications for SSM Destination
	Addresses)

	T12 DONE Review updates of RPF entries.
	FIXME pim_upstream.c send_join():
	Currently only one upstream state is affected by detection of RPF change.
	RPF change should affect all upstream states sharing the RPF cache.

	T13 DONE Check that RFC macros using S,G,RPF_interface(S) are actually
	implemented with this strategy:
	rpf_ifch=find_ifch(up->rpf->interface).
	See pim_rpf.c pim_rpf_find_rpf_addr() for a correct example.

	$ grep -i macro pimd/*.c
	pimd/pim_iface.c: RFC 4601: 4.1.6. State Summarization Macros
	pimd/pim_ifchannel.c: RFC 4601: 4.6.5. Assert State Macros
	pimd/pim_ifchannel.c: RFC 4601: 4.1.6. State Summarization Macros
	pimd/pim_ifchannel.c: RFC 4601: 4.1.6. State Summarization Macros
	pimd/pim_ifchannel.c: RFC 4601: 4.6.5. Assert State Macros
	pimd/pim_ifchannel.c: Macro:
	pimd/pim_rpf.c: RFC 4601: 4.1.6. State Summarization Macros

	T14 DONE Send Assert(S,G) on iif as response to WRONGVIF kernel upcall.
	See pim_mroute.c mroute_msg().

	T15 DONE Interface command to statically join (S,G).
	interface eth0
	ip igmp join-group 239.1.1.1 source 1.1.1.1

	T16 DONE RPF'(S,G) lookup is not working for S reachable with default route.
	See "RPF'(S,G) not found" in pim_rpf_update() from pim_rpf.c.
	Zebra daemon RIB is not reflecting changes in kernel routes
	accurately?

	T17 DONE Prevent CLI from creating bogus interfaces.
	Example:
	conf t
	interface xxx

	T18 Consider reliable pim solution (refresh reduction)
	A Reliable Transport Mechanism for PIM
	http://tools.ietf.org/wg/pim/draft-ietf-pim-port/
	PORT=PIM-Over-Reliable-Transport

	T19 DONE Fix self as neighbor
	See mailing list post:
	http://lists.gnu.org/archive/html/qpimd-users/2009-04/msg00000.html

	T20 DONE Fix debug message: "pim_neighbor_update: internal error:
	trying to replace same prefix list"
	See mailing list post:
	http://lists.gnu.org/archive/html/qpimd-users/2009-04/msg00000.html

	T21 DONE Clean-up PIM/IGMP interface mismatch debugging
	See option PIM_CHECK_RECV_IFINDEX_SANITY in pimd/Makefile.am
	See mailing list post:
	http://lists.nongnu.org/archive/html/qpimd-users/2009-04/msg00003.html

	T22 DONE IGMP must be protected against adding looped MFC entries
	created by both source and receiver attached to the same
	interface.

	T23 DONE libzebra crash after zclient_lookup_nexthop.
	See mailing list post:
	http://lists.nongnu.org/archive/html/qpimd-users/2009-04/msg00008.html

	T24 DONE zserv may return recursive routes:
	- nexthop type is set to ZEBRA_NEXTHOP_IPV4
	- ifindex is not reported
	- calls expecting ifindex (fib_lookup_if_vif_index) are disrupted
	See also this mailing list post:
	[PATCH 21/21] Link detect and recursive routes
	http://www.gossamer-threads.com/lists/quagga/dev/17564

	T25 DONE Zclient nexthop lookup missing OSPF route to 1.1.1.1/32
	See also:
	pim_zlookup.c zclient_lookup_nexthop misses OSPF 1.1.1.1/32
	zebra/zebra_vty.c show_ip_route_addr_cmd hits OSPF 1.1.1.1/32

	T26 DONE Zebra daemon is marking recursive static route as inactive.

	FIXED: zebra daemon was incorrectly marking recursive routes
	pointing to kernel routes as inactive:
	zebra/zebra_rib.c nexthop_active_ipv4:
	-- Original:
	else if (CHECK_FLAG (rib->flags, ZEBRA_FLAG_INTERNAL))
	-- Fixed:
	else if (CHECK_FLAG (rib->flags, ZEBRA_FLAG_INTERNAL) \|\|
	match->type == ZEBRA_ROUTE_KERNEL)

	Old problem description:

	This prevents rib_match_ipv4 from returning its nexthop:
	client: pim_zlookup.c zclient_read_nexthop
	server: zebra/zserv.c zsend_ipv4_nexthop_lookup_v2 -> rib_match_ipv4

	Kernel route is injected into zebra in zebra_rib.c rib_add_ipv4
	Examples:
	rt_netlink.c:726: rib_add_ipv4 (ZEBRA_ROUTE_KERNEL, flags, &p, gate, src, index, table, metric, 0);
	rt_netlink.c:864: rib_add_ipv4 (ZEBRA_ROUTE_KERNEL, 0, &p, gate, src, index, table, 0, 0);

	This patch didn't fix the issue:
	[PATCH 21/21] Link detect and recursive routes
	http://www.gossamer-threads.com/lists/quagga/dev/17564

	See the example below for the route 2.2.2.2.

	bash# route add -host 1.1.1.1 gw 127.0.0.1
	bash# route add -host 2.2.2.2 gw 1.1.1.1
	bash# netstat -nvr
	Kernel IP routing table
	Destination Gateway Genmask Flags MSS Window irtt Iface
	2.2.2.2 1.1.1.1 255.255.255.255 UGH 0 0 0 lo
	1.1.1.1 127.0.0.1 255.255.255.255 UGH 0 0 0 lo
	192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
	0.0.0.0 192.168.0.2 0.0.0.0 UG 0 0 0 eth0
	bash#

	zebra# sh ip route
	Codes: K - kernel route, C - connected, S - static, R - RIP, O - OSPF,
	I - ISIS, B - BGP, > - selected route, * - FIB route

	K>* 0.0.0.0/0 via 192.168.0.2, eth0
	K>* 1.1.1.1/32 via 127.0.0.1, lo
	K * 2.2.2.2/32 via 1.1.1.1, lo inactive
	C>* 127.0.0.0/8 is directly connected, lo
	C>* 192.168.0.0/24 is directly connected, eth0

	quagga-pimd-router# sh ip route 1.1.1.1
	Address NextHop Interface Metric Preference
	1.1.1.1 127.0.0.1 lo 0 0
	quagga-pimd-router#
	quagga-pimd-router# sh ip route 2.2.2.2
	Address NextHop Interface Metric Preference
	2.2.2.2 192.168.0.2 eth0 0 0
	quagga-pimd-router#

	T27 DONE Implement debug command
	test pim receive assert
	See also TODO T6: (S,G) Assert state machine.

	T28 DONE Bad IPv4 address family=02 in Join/Prune dump
	Reported by Andrew Lunn <andrew.lunn@ascom.ch>

	# 58-byte pim v2 Join/Prune dump
	# ------------------------------
	# IPv4 address family=02 is wrong, correct IPv4 address family is 01
	# See http://www.iana.org/assignments/address-family-numbers
	#
	c8XX YY03 : ip src 200.xx.yy.3
	e000 000d : ip dst 224.0.0.13
	9404 0000 : ip router alert option 148.4.0.0
	2300 ab13 : pimv2,type=3 res=00 checksum=ab13
	0200 : upstream family=02, encoding=00
	c8XX YY08 : upstream 200.xx.yy.8
	0001 00d2 : res=00 groups=01 holdtime=00d2
	0200 0020 : group family=02, encoding=00, res=00, mask_len=20
	ef01 0101 : group address 239.1.1.1
	0001 0000 : joined=0001 pruned=0000
	0200 0020 : source family=02, encoding=00, res=00, mask_len=20
	0101 0101 : source address 1.1.1.1

	T29 DONE Reset interface PIM-hello-sent counter when primary address changes
	See pim_ifp->pim_ifstat_hello_sent

	RFC 4601: 4.3.1. Sending Hello Messages

	Thus, if a router needs to send a Join/Prune or Assert message on
	an interface on which it has not yet sent a Hello message with the
	currently configured IP address, then it MUST immediately send the
	relevant Hello message without waiting for the Hello Timer to
	expire, followed by the Join/Prune or Assert message.

	T30 DONE Run interface DR election when primary address changes
	Reported by Andrew Lunn <andrew.lunn@ascom.ch>
	See pim_if_dr_election().

	T31 If an interface changes one of its secondary IP addresses, a Hello
	message with an updated Address_List option and a non-zero
	HoldTime should be sent immediately.
	See also detect_secondary_address_change
	See also CAVEAT C15.
	See also RFC 4601: 4.3.1. Sending Hello Messages

	T32 FIXED Detection of interface primary address changes may fail when
	there are multiple addresses.
	See also CAVEAT C14.

	pim_find_primary_addr() should return interface primary address
	from connected list. Currently it returns the first address.

	Zebra daemon "show int" is able to keep the primary address as
	first address.

	T33 DONE Implement debug command: test pim receive upcall
	See also TODO T6: (S,G) Assert state machine.

	T34 DONE assert_action_a1

	T35 DONE Review macros depending on interface I.

	See also: grep ,I\) pimd/*.c

	For the case (S,G,I) check if I is either
	1) interface attached to this per-interface S,G state (don't think so)
	or
	2) an arbitrary interface (most probably)

	For the arbitrary interface case (2), consider representing
	interface ifp as its primary address (struct in_addr ifaddr). The
	benefit is in_addr does not need to be dereferenced, so it does
	not demand protection against crashes.

	T36 DONE React to zebra daemon link-detect up/down notification.
	pim_ifp->primary_address is managed by detect_primary_address_change()
	depending on to ifp->connected (managed by zebra_interface_address_read()).

	T37 DONE Review list of variables which may affect pim_upstream.c
	pim_upstream_evaluate_join_desired().
	Call pim_upstream_update_join_desired() accordingly.

	See the order of invokation:
	pim_if_dr_election(ifp);
	pim_if_update_join_desired(pim_ifp); /* depends on DR */
	pim_if_update_could_assert(ifp); /* depends on DR */
	pim_if_update_my_assert_metric(ifp); /* depends on could_assert */

	join_desired depends on:
	pim_ifp->primary_address
	pim_ifp->pim_dr_addr
	ch->ifassert_winner_metric
	ch->ifassert_winner
	ch->local_ifmembership
	ch->ifjoin_state
	ch->upstream->rpf.source_nexthop.mrib_metric_preference
	ch->upstream->rpf.source_nexthop.mrib_route_metric
	ch->upstream->rpf.source_nexthop.interface

	T38 DONE Detect change in AssertTrackingDesired(S,G,I)

	See the order of invokation:
	dr_election: none
	update_join_desired: depends on DR
	update_tracking_desired: depends on DR, join_desired

	AssertTrackingDesired(S,G,I) depends on:
	pim_ifp->primary_address
	pim_ifp->pim_dr_addr
	ch->local_ifmembership
	ch->ifassert_winner
	ch->ifjoin_state
	ch->upstream->rpf.source_nexthop.interface
	PIM_UPSTREAM_FLAG_TEST_DR_JOIN_DESIRED(ch->upstream->flags)

	T39 DONE AssertTrackingDesired: flags is not matching evaluation

	# show ip pim assert-internal
	CA: CouldAssert
	ECA: Evaluate CouldAssert
	ATD: AssertTrackingDesired
	eATD: Evaluate AssertTrackingDesired

	Interface Address Source Group CA eCA ATD eATD
	eth0 192.168.1.100 1.1.1.1 239.1.1.1 no no no yes
	#

	T40 Lightweight MLDv2
	http://tools.ietf.org/html/draft-ietf-mboned-lightweight-igmpv3-mldv2-05
	http://www.ietf.org/internet-drafts/draft-ietf-mboned-lightweight-igmpv3-mldv2-05.txt
	http://www.ietf.org/html.charters/mboned-charter.html

	T41 DONE ssmping support

	See also:
	http://www.venaas.no/multicast/ssmping/
	draft-ietf-mboned-ssmping-07
	http://tools.ietf.org/html/draft-ietf-mboned-ssmping-07

	Example:

	debug ssmpingd

	conf t
	ip ssmpingd 1.1.1.1

	show ip ssmpingd

	T42 Static igmp join fails when loading config at boot time

	! Wrong behavior seen at boot time:
	!
	2010/02/22 08:59:00 PIM: igmp_source_forward_start: ignoring request for
	looped MFC entry (S,G)=(3.3.3.3,239.3.3.3): igmp_sock=12 oif=eth0 vif_index=2

	! Correct behavior seen later:
	!
	2010/02/22 09:03:16 PIM: igmp_source_forward_start: ignoring request for
	looped MFC entry (S,G)=(2.2.2.2,239.2.2.2): igmp_sock=17 oif=lo vif_index=1

	! To see the wrong message at boot:
	!
	debug igmp trace
	!
	interface lo
	ip igmp
	ip igmp join 239.2.2.2 2.2.2.2
	ip igmp join 239.3.3.3 3.3.3.3
	!

	! Interfaces indexes:
	Interface Address ifi Vif PktsIn PktsOut BytesIn BytesOut
	eth0 200.202.112.3 2 2 0 0 0 0
	lo 127.0.0.1 1 1 0 0 0 0

	T43 PIM Neighbor Reduction
	https://datatracker.ietf.org/doc/draft-wijnands-pim-neighbor-reduction/

	"In a transit LAN (no directly connected source or receiver), many
	of the PIM procedures don't apply. (...) This proposal describes
	a procedure to reduce the amount of neighbors established over a
	transit LAN."

	T44 Single Stream Multicast Fast Reroute (SMFR) Method
	https://datatracker.ietf.org/doc/draft-liu-pim-single-stream-multicast-frr/

	"This document proposes an IP multicast fast convergence method
	based on differentiating primary and backup PIM join."

	T45 RFC5384 - The Join Attribute Format
	"This document describes a modification of the Join message that
	allows a node to associate attributes with a particular tree."

	T46 PIM Multi-Topology ID (MT-ID) Join-Attribute
	http://tools.ietf.org/html/draft-cai-pim-mtid-00
	Depends on T45.

	"This draft introduces a new type of PIM Join Attribute used to
	encode the identity of the topology PIM uses for RPF."

	-x-