Usage Guidelines
Use the PIM
routing topology table to display various entries for a given group, (*, G),
(S, G), and
(S, G) RPT, each
with its own interface list.
PIM communicates
the contents of these entries through the Multicast Routing Information Base
(MRIB), which is an intermediary for communication between multicast routing
protocols, such as PIM; local membership protocols, such as Internet Group
Management Protocol (IGMP); and the multicast forwarding engine of the system.
The MRIB shows on
which interface the data packet should be accepted and on which interfaces the
data packet should be forwarded, for a given (S, G) entry. Additionally, the
Multicast Forwarding Information Base (MFIB) table is used during forwarding to
decide on per-packet forwarding actions.
When multicast-only
fast reroute (MoFRR) feature is enabled, the
show pim
topology
command shows the SGs that are configured for MoFRR. For
information about the MoFRR primary and secondary paths, see the description of
the command
show pim topology detail.
Note |
For forwarding
information, use the
show mfib
route
and
show mrib
route
commands.
|
Examples
The following is
sample output from the
show pim
topology
command:
RP/0/RP0/CPU0:router# show pim topology
IP PIM Multicast Topology Table
Entry state: (*/S,G)[RPT/SPT] Protocol Uptime Info
Entry flags: KAT - Keep Alive Timer, AA - Assume Alive, PA - Probe Alive,
RA - Really Alive, LH - Last Hop, DSS - Don't Signal Sources,
RR - Register Received, SR - Sending Registers, E - MSDP External, EX - Extranet
DCC - Don't Check Connected,
ME - MDT Encap, MD - MDT Decap,
MT - Crossed Data MDT threshold, MA - Data MDT group assigned
Interface state: Name, Uptime, Fwd, Info
Interface flags: LI - Local Interest, LD - Local Dissinterest,
II - Internal Interest, ID - Internal Dissinterest,
LH - Last Hop, AS - Assert, AB - Admin Boundary
(11.0.0.1,239.9.9.9)SPT SM Up: 00:00:13
JP: Join(never) RPF: Loopback1,11.0.0.1* Flags: KAT(00:03:16) RA RR
No interfaces in immediate olist
(*,239.9.9.9) SM Up: 4d14h RP: 11.0.0.1*
JP: Join(never) RPF: Decapstunnel0,11.0.0.1 Flags: LH
POS0/3/0/0 4d14h fwd LI II LH
(*,224.0.1.39) DM Up: 02:10:38 RP: 0.0.0.0
JP: Null(never) RPF: Null,0.0.0.0 Flags: LH DSS
POS0/2/0/0 02:10:38 off LI II LH
(*,224.0.1.40) DM Up: 03:54:23 RP: 0.0.0.0
JP: Null(never) RPF: Null,0.0.0.0 Flags: LH DSS
POS0/2/0/0 03:54:23 off LI II LH
POS0/2/0/2 03:54:14 off LI
POS0/4/0/0 03:53:37 off LI
(*,239.100.1.1) BD Up: 03:51:35 RP: 200.6.1.6
JP: Join(00:00:24) RPF: POS0/4/0/0,10.10.4.6 Flags:
POS0/2/0/0 03:42:05 fwd Join(00:03:18)
POS0/2/0/2 03:51:35 fwd Join(00:02:54)
(*,235.1.1.1) SM Up: 03:51:39 RP: 200.6.2.6
JP: Join(00:00:50) RPF: POS0/4/0/0,10.10.4.6 Flags:
POS0/2/0/2 02:36:09 fwd Join(00:03:20)
POS0/2/0/0 03:42:04 fwd Join(00:03:16)
The following example
shows output for a MoFRR convergence:
RP/0/RP0/CPU0:router# show pim topology 239.1.1.1
IP PIM Multicast Topology Table
Entry state: (*/S,G)[RPT/SPT] Protocol Uptime Info
Entry flags: KAT - Keep Alive Timer, AA - Assume Alive, PA - Probe Alive,
RA - Really Alive, LH - Last Hop, DSS - Don't Signal Sources,
MF – MOFRR Enabled, MFP – Primary MoFRR,
MFB – Backup MoFRR, MFA – Active MoFRR,
RR - Register Received, SR - Sending Registers, E - MSDP External,
DCC - Don't Check Connected,
ME - MDT Encap, MD - MDT Decap,
MT - Crossed Data MDT threshold, MA - Data MDT group assigned
Interface state: Name, Uptime, Fwd, Info
Interface flags: LI - Local Interest, LD - Local Dissinterest,
II - Internal Interest, ID - Internal Dissinterest,
LH - Last Hop, AS - Assert, AB - Admin Boundary
(192.1.1.2,239.1.1.1)SPT SSM Up: 13:54:06
JP: Join(00:00:41) RPF: GigabitEthernet0/5/0/3.3,100.100.0.10 MoFRR RIB, Flags:
GigabitEthernet0/5/0/1 13:54:06 fwd LI LH
RP/0/4/CPU0:Sunnyvale#show pim topology 239.1.1.1 detail
IP PIM Multicast Topology Table
Entry state: (*/S,G)[RPT/SPT] Protocol Uptime Info
Entry flags: KAT - Keep Alive Timer, AA - Assume Alive, PA - Probe Alive,
RA - Really Alive, LH - Last Hop, DSS - Don't Signal Sources,
RR - Register Received, SR - Sending Registers, E - MSDP External,
DCC - Don't Check Connected,
ME - MDT Encap, MD - MDT Decap,
MT - Crossed Data MDT threshold, MA - Data MDT group assigned
Interface state: Name, Uptime, Fwd, Info
Interface flags: LI - Local Interest, LD - Local Dissinterest,
II - Internal Interest, ID - Internal Dissinterest,
LH - Last Hop, AS - Assert, AB - Admin Boundary
(192.1.1.2,239.1.1.1)SPT SSM Up: 13:54:10
JP: Join(00:00:37) RPF: GigabitEthernet0/5/0/3.3,100.100.0.10 MoFRR RIB, Flags:
RPF Table: IPv4-Unicast-default
RPF Secondary: GigabitEthernet0/5/0/3.2,100.100.200.10
GigabitEthernet0/5/0/1 13:54:10 fwd LI LH
This table
describes the significant fields shown in the display. It includes fields that
do not appear in the example, but that may appear in your output.
Table 26. show pim
topology Field Descriptions
Field
|
Description
|
(11.0.0.1,239.9.9.9)SPT
|
Entry
state. Source address, group address, and tree flag (shortest path tree or
rendezvous point tree) for the route entry. Note that the tree flag may be
missing from the entry.
|
SM
|
Entry
protocol. PIM protocol mode in which the entry operates: sparse mode (SM),
source specific multicast (SSM),
bidirectional (BD),
or
dense-mode (DM).
|
Up:
00:00:13
|
Entry
uptime. Time (in hours, minutes, and seconds) this entry has existed in the
topology table.
|
RP:
11.0.0.1*
|
Entry
information. Additional information about the route entry. If route entry is a
sparse mode
or
bidirectional PIM
route,
the RP address is given.
|
JP:
Null(never)
|
Entry
join/prune state. Indicates if and when a join or prune message is sent to the
RPF neighbor for the route.
|
MoFRR RIB,
Flags:
|
Indicates
whether the (S,G) route is a RIB-based MoFRR route.
|
MoFRR,
Flags:
|
Indicates
whether the (S,G) route is a flow-based MoFRR route. By default, a flow-based
MoFRR route will be a RIB-based MoFRR route but not in the reverse way.
|
RPF Table
|
IPv4
Unicast default.
|
RPF
Secondary
|
Secondary
path interface
|
Entry
Information Flags
|
KAT - Keep
Alive Timer
|
The
keepalive timer tracks whether traffic is flowing for the (S, G) route on which
it is set. A route does not time out while the KAT is running. The KAT runs for
3.5 minutes, and the route goes into KAT probing mode for as long as 65
seconds. The route is deleted if no traffic is seen during the probing
interval, and there is no longer any reason to keep the route—for example,
registers and (S, G) joins.
|
AA -
Assume Alive
|
Flag that
indicates that the route was alive, but recent confirmation of traffic flow was
not received.
|
PA - Probe
Alive
|
Flag that
indicates that the route is probing the data plane to determine if traffic is
still flowing for this route before it is timed out.
|
RA -
Really Alive
|
Flag that
indicates that the source is confirmed to be sending traffic for the route.
|
LH - Last
Hop
|
Flag that
indicates that the entry is the last-hop router for the entry. If (S, G) routes
inherit the LH olist from an (*, G) route, the route entry LH flag appears only
on the (*, G) route.
|
IA -
Inherit Alive
|
Flag that
indicates a source VPN routing and forwarding (VRF) route with the KAT active.
|
DSS -
Don’t Signal Sources
|
Flag that
may be set on the last-hop (*, G) entries that indicates that new matching
sources should not be signaled from the forwarding plane.
|
DCC -
Don’t Check Connected
|
Flag that
is set when the KAT probes, which indicates that the connected check for new
sources should be omitted in the forwarding plane.
|
RR -
Register Received
|
Flag that
indicates that the RP has received and answered PIM register messages for this
(S, G) route.
|
SR -
Sending Registers
|
Flag that
indicates that the first-hop DR has begun sending registers for this (S, G)
route, but has not yet received a Register-Stop message.
|
E - MSDP
External
|
Flag that
is set on those entries that have sources, learned through Multicast Source
Discovery Protocol (MSDP), from another RP.
|
ME - MDT
Encap
|
Flag that
indicates a core encapsulation route for a multicast distribution tree (MDT).
|
MD - MDT
Decap
|
Flag that
indicates a core decapsulation route for an MDT.
|
MT -
Crossed Data MDT threshold
|
Flag that
indicates that traffic on this route passed a threshold for the data MDT.
|
MA - Data
MDT group assigned
|
Flag that
indicates a core encapsulation route for the data MDT.
|
POS0/2/0/0
|
Interface
name. Name of an interface in the interface list of the entry.
|
03:54:23
|
Interface
uptime. Time (in hours, minutes, and seconds) this interface has existed in the
entry.
|
off
|
Interface
forwarding status. Outgoing forwarding status of the interface for the entry is
“fwd” or “off”.
|
Interface
Information Flags
|
LI - Local
Interest
|
Flag that
indicates that there are local receivers for this entry on this interface, as
reported by Internet Group Management Protocol (IGMP).
|
LD - Local
Disinterest
|
Flag that
indicates that there is explicit disinterest for this entry on this interface,
as reported by IGMP exclude mode reports.
|
II -
Internal Interest
|
Flag that
indicates that the host stack of the router has internal receivers for this
entry.
|
ID -
Internal Disinterest
|
Flag that
indicates that the host stack of the router has explicit internal disinterest
for this entry.
|
LH - Last
Hop
|
Flag that
indicates that this interface has directly connected receivers and this router
serves as a last hop for the entry. If the (S, G) outgoing interface list is
inherited from a (*, G) route, the LH flag is set on the (*, G) outgoing LH
interface.
|
AS -
Assert
|
Flag that
indicates that a PIM assert message was seen on this interface and the active
PIM assert state exists.
|
AB -
Administrative Boundary
|
Flag that
indicates that forwarding on this interface is blocked by a configured
administrative boundary for this entry’s group range.
|