Bidir PIM

Bidirectional shared trees use the same tree for traffic from sources towards RP and from RP to receivers

On each link, the router with the best path to the RP is elected to be the Designated Forwarder
The Designated Forwarder is responsible for forwarding upstream towards the RP

ROSH#

ROSH#sh run
Building configuration...

Current configuration : 1417 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname ROSH
!
boot-start-marker
boot-end-marker
!
!
ip subnet-zero
ip cef
!
!
no ip domain-lookup
!
ip multicast-routing 
no mpls traffic-eng auto-bw timers frequency 0
call rsvp-sync
!         
!
!
!
!
!
!
!
interface Loopback0
 ip address 172.18.5.5 255.255.255.255
 no clns route-cache
!
interface FastEthernet0/0
 no ip address
 shutdown
 duplex half
 no clns route-cache
!
interface FastEthernet1/0
 ip address 172.18.25.5 255.255.255.0
 ip pim sparse-mode
 duplex auto
 speed auto
 no clns route-cache
!
interface FastEthernet1/1
 ip address 10.255.1.2 255.255.255.0
 ip pim sparse-mode
 duplex auto
 speed auto
 standby 1 ip 10.255.1.1
 standby 1 priority 105
 standby 1 preempt
 no clns route-cache
!
router ospf 1
 log-adjacency-changes
 network 10.255.1.2 0.0.0.0 area 0
 network 172.18.5.5 0.0.0.0 area 0
 network 172.18.25.5 0.0.0.0 area 0
!
ip classless
!
no ip http server
!
ip pim bidir-enable
ip pim autorp listener
!
!
no cdp run
!
!
!
control-plane
!
!
dial-peer cor custom
!
!
!
alias exec si show ip int brie
alias exec sr sh ip route
alias exec son show ip ospf neigh
alias exec vrf show ip vrf interface
alias exec sib show ip bgp vpnv4 all summ
alias exec srb sh run | b router bgp
!
line con 0
 exec-timeout 0 0
 logging synchronous
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
!
!
end

ROSH#       

RISH#

RISH#sh run
Building configuration...

Current configuration : 1693 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname RISH
!
boot-start-marker
boot-end-marker
!
!
ip subnet-zero
ip cef
!
!
no ip domain-lookup
!
ip multicast-routing 
no mpls traffic-eng auto-bw timers frequency 0
call rsvp-sync
!         
!
!
!
!
!
!
!
interface Loopback0
 ip address 172.18.1.1 255.255.255.255
 ip pim sparse-mode
 no clns route-cache
!
interface FastEthernet0/0
 no ip address
 shutdown
 duplex half
 no clns route-cache
!
interface FastEthernet1/0
 ip address 172.18.31.1 255.255.255.0
 ip pim sparse-mode
 duplex auto
 speed auto
!
interface FastEthernet1/1
 ip address 172.18.12.3 255.255.255.0
 ip pim sparse-mode
 duplex auto
 speed auto
 no clns route-cache
!
interface FastEthernet2/0
 ip address 10.255.1.3 255.255.255.0
 ip pim sparse-mode
 duplex auto
 speed auto
 standby 1 ip 10.255.1.1
 standby 1 preempt
 no clns route-cache
!
interface FastEthernet2/1
 no ip address
 shutdown
 duplex auto
 speed auto
 no clns route-cache
!
router ospf 1
 log-adjacency-changes
 network 10.255.1.3 0.0.0.0 area 0
 network 172.18.1.1 0.0.0.0 area 0
 network 172.18.12.3 0.0.0.0 area 0
 network 172.18.31.1 0.0.0.0 area 0
!
ip classless
!
no ip http server
!
ip pim bidir-enable
ip pim autorp listener
ip pim send-rp-discovery scope 10
!
!
no cdp run
!
!
!
control-plane
!         
!
dial-peer cor custom
!
!
!
alias exec si show ip int brie
alias exec sr sh ip route
alias exec son show ip ospf neigh
alias exec vrf show ip vrf interface
alias exec sib show ip bgp vpnv4 all summ
alias exec srb sh run | b router bgp
!
line con 0
 exec-timeout 0 0
 logging synchronous
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
!
!
end
          
RISH# 

PT#

PT#sh run
Building configuration...

Current configuration : 1465 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname PT
!
boot-start-marker
boot-end-marker
!
!
ip subnet-zero
ip cef
!
!
no ip domain-lookup
!
ip multicast-routing 
no mpls traffic-eng auto-bw timers frequency 0
call rsvp-sync
!         
!
!
!
!
!
!
!
interface Loopback0
 ip address 172.18.3.3 255.255.255.255
 ip pim sparse-mode
 no clns route-cache
!
interface FastEthernet0/0
 no ip address
 shutdown
 duplex half
 no clns route-cache
!
interface FastEthernet1/0
 ip address 172.18.43.3 255.255.255.0
 ip pim sparse-mode
 duplex auto
 speed auto
 no clns route-cache
!
interface FastEthernet1/1
 ip address 172.18.31.3 255.255.255.0
 ip pim sparse-mode
 duplex auto
 speed auto
 no clns route-cache
!
router ospf 1
 log-adjacency-changes
 network 172.18.3.3 0.0.0.0 area 0
 network 172.18.31.3 0.0.0.0 area 0
 network 172.18.43.3 0.0.0.0 area 0
!
ip classless
!
no ip http server
!
ip pim bidir-enable
ip pim autorp listener
ip pim send-rp-announce Loopback0 scope 10 group-list 1 bidir
!         
!
access-list 1 permit 239.0.0.0 0.255.255.255
!
!
!
control-plane
!
!
dial-peer cor custom
!
!
!
alias exec si show ip int brie
alias exec sr sh ip route
alias exec son show ip ospf neigh
alias exec vrf show ip vrf interface
alias exec sib show ip bgp vpnv4 all summ
alias exec srb sh run | b router bgp
!
line con 0
 exec-timeout 0 0
 logging synchronous
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
!
!
end

PT#          

TA#

TA#
TA#
TA#
TA#sh run
Building configuration...

Current configuration : 1732 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname TA
!
boot-start-marker
boot-end-marker
!
!
ip subnet-zero
ip cef
!
!
no ip domain-lookup
!
ip multicast-routing 
no mpls traffic-eng auto-bw timers frequency 0
call rsvp-sync
!         
!
!
!
!
!
!
!
interface Loopback0
 ip address 172.18.2.2 255.255.255.255
 ip pim sparse-mode
 no clns route-cache
!
interface FastEthernet0/0
 no ip address
 shutdown
 duplex half
 no clns route-cache
!
interface FastEthernet1/0
 ip address 172.18.42.2 255.255.255.0
 ip pim sparse-mode
 duplex auto
 speed auto
 no clns route-cache
!
interface FastEthernet1/1
 ip address 172.18.12.2 255.255.255.0
 ip pim sparse-mode
 duplex auto
 speed auto
 no clns route-cache
!
interface FastEthernet2/0
 ip address 172.18.25.3 255.255.255.0
 ip pim sparse-mode
 duplex auto
 speed auto
 no clns route-cache
!
interface FastEthernet2/1
 no ip address
 shutdown
 duplex auto
 speed auto
 no clns route-cache
!         
router ospf 1
 log-adjacency-changes
 network 172.18.2.2 0.0.0.0 area 0
 network 172.18.12.2 0.0.0.0 area 0
 network 172.18.25.3 0.0.0.0 area 0
 network 172.18.42.2 0.0.0.0 area 0
!
ip classless
!
no ip http server
!
ip pim bidir-enable
ip pim autorp listener
ip pim send-rp-announce Loopback0 scope 10 group-list 1 bidir
!
!
access-list 1 permit 239.0.0.0 0.255.255.255
!
!
!
control-plane
!
!         
dial-peer cor custom
!
!
!
alias exec si show ip int brie
alias exec sr sh ip route
alias exec son show ip ospf neigh
alias exec vrf show ip vrf interface
alias exec sib show ip bgp vpnv4 all summ
alias exec srb sh run | b router bgp
!
line con 0
 exec-timeout 0 0
 logging synchronous
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
!
!
end

TA#                                     

HFA#

HFA#sh run
Building configuration...

Current configuration : 1627 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname HFA
!
boot-start-marker
boot-end-marker
!
!
ip subnet-zero
ip cef
!
!
no ip domain-lookup
!
ip multicast-routing 
no mpls traffic-eng auto-bw timers frequency 0
call rsvp-sync
!         
!
!
!
!
!
!
!
interface Loopback0
 ip address 172.18.4.4 255.255.255.255
 no clns route-cache
!
interface FastEthernet0/0
 no ip address
 shutdown
 duplex half
 no clns route-cache
!
interface FastEthernet1/0
 ip address 10.223.1.2 255.255.255.252
 ip igmp join-group 239.8.1.1
 duplex auto
 speed auto
 no clns route-cache
!
interface FastEthernet1/1
 ip address 172.18.43.4 255.255.255.0
 ip pim sparse-mode
 duplex auto
 speed auto
 no clns route-cache
!
interface FastEthernet2/0
 ip address 172.18.42.4 255.255.255.0
 ip pim sparse-mode
 duplex auto
 speed auto
 no clns route-cache
!
interface FastEthernet2/1
 no ip address
 shutdown
 duplex auto
 speed auto
 no clns route-cache
!
router ospf 1
 log-adjacency-changes
 network 10.223.1.2 0.0.0.0 area 0
 network 172.18.4.4 0.0.0.0 area 0
 network 172.18.42.4 0.0.0.0 area 0
 network 172.18.43.4 0.0.0.0 area 0
!
ip classless
!
no ip http server
!
ip pim bidir-enable
ip pim autorp listener
!
!
no cdp run
!
!
!
control-plane
!
!
dial-peer cor custom
!         
!
!
alias exec si show ip int brie
alias exec sr sh ip route
alias exec son show ip ospf neigh
alias exec vrf show ip vrf interface
alias exec sib show ip bgp vpnv4 all summ
alias exec srb sh run | b router bgp
!
line con 0
 exec-timeout 0 0
 logging synchronous
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
!
!
end

HFA#

All Pim router Domin are enable the pim Bidir
using ip pim bidir-enable command

 PIM Bidir need a RP we use here a auto-rp
Every router link election the DF win base on the metric,by the Offer message on the link

ROSH#sh ip route 172.18.3.3
Routing entry for 172.18.3.3/32
  Known via "ospf 1", distance 110, metric 3, type intra area
  Last update from 10.255.1.3 on FastEthernet1/1, 10:23:18 ago
  Routing Descriptor Blocks:
  * 10.255.1.3, from 172.18.3.3, 10:23:18 ago, via FastEthernet1/1
      Route metric is 3, traffic share count is 1

RISH#sh ip route  172.18.3.3
Routing entry for 172.18.3.3/32
  Known via "ospf 1", distance 110, metric 2, type intra area
  Last update from 172.18.31.3 on FastEthernet1/0, 10:23:51 ago
  Routing Descriptor Blocks:
  * 172.18.31.3, from 172.18.3.3, 10:23:51 ago, via FastEthernet1/0
      Route metric is 2, traffic share count is 1

debug ip pim df 

     11:34:57: PIM(0): Receive DF Winner message from 10.255.1.3 on FastEthernet1/1 (Non-DF)
11:34:57: PIM(0): RP 172.18.3.3, pref 110, metric 2
11:34:57: PIM(0): Metric is better

debug ip pim df 

11:35:02: PIM(0): Send v2 Winner on FastEthernet2/0 (DF) for RP 172.18.3.3
11:35:02: PIM(0): Sender 10.255.1.3, pref 110, metric 2

The show ip mroute output  on HFA shown the (*,239.8.1.1) entry FastEthernet1/1 present in both incoming and outgoing interface list as Bidir-upstream. This is not possible in PIM-SM

HFA#sh ip mroute  239.8.1.1
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
       L - Local, P - Pruned, R - RP-bit set, F - Register flag,
       T - SPT-bit set, J - Join SPT, M - MSDP created entry,
       X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
       U - URD, I - Received Source Specific Host Report, Z - Multicast Tunnel
       Y - Joined MDT-data group, y - Sending to MDT-data group
Outgoing interface flags: H - Hardware switched, A - Assert winner
 Timers: Uptime/Expires
 Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 239.8.1.1), 00:00:42/00:02:59, RP 172.18.3.3, flags: BPL
  Bidir-Upstream: FastEthernet1/1, RPF nbr 172.18.43.3
  Outgoing interface list:
    FastEthernet1/1, Bidir-Upstream/Sparse, 00:00:42/00:00:00