Hi, my consideration are correct for the multicast protocol ?
As for the command "ip pim rp-address 173.17.2.1 VALID_GROUP" which is on the site of Padriciano I did a search and, practically, it automatically creates a tunnel interface.
This thing, as I said, you need to create / enable multicast. Being something of CCNP R & S do not know the different syntax but "PIM" stands for Protocol-Independent Multicast.
Because you do not have to do often directly with the multicast explain it to follow but it is as a reality check for me:
Multicast uses the connectionless protocol UDP for transport (transport layer, Layer 4 - L4) and allows you to send, with just sending the same packet to multiple nodes; since UDP does not guarantee delivery. You can think of as a multicast broadcast changed.
For example: if you have 6 nodes (node = router), for simplicity called ABCDEF, and the node A has to send a packet only to nodes BCDF (excluding the node E) then, with multicast, the packet is sent only once and is delivered to all hosts BCD F.
That's the theory but in practice petty commands ip pim NOT know them being the subject of CCNP R & S.
>> A concrete example of multicast: the election of the DR (Designated Router) and the Des BDR (Backup ignated Router) in multiaccess networks (such as Frame Relay networks) with OSPF.
All routers in the network that are NOT DR or BDR are Drothers (read as DR-Others). The Drothers can only communicate with the DR (simultaneously with the BDR).
This feature allows you to NOT flood the LSA (Link State Advertisement) to all routers in the network so that only the Drothers send their LSA to the DR and BDR using the multicast address 224.0.0.6 IPv4 or IPv6 multicast address ff02 :: 6.
224.0.0.6 and ff02 :: 6 = all routers DR
When the DR receives packets is responsible for forwarding these LSA to all other routers. The DR uses the multicast address 224.0.0.5 IPv4 or IPv6 multicast address ff02 :: 5. The end result is that there is only one router that does the flooding of all LSA in the multiaccess network.
>> 224.0.0.5 and ff02 :: 5 = all OSPF routers
ip multicast-routing
interface GigabitEthernet0/1.134
description LAN EDA
encapsulation dot1Q 134
ip address 134.1.192.31 255.255.255.240
no ip redirects
ip directed-broadcast
!
standby 134 ip 134.1.192.33
standby 134 timers msec 300 msec 950
standby 134 priority 90
standby 134 preempt delay reload 10
no shutdown
!
!
router ospf 1
network 134.1.192.32 255.255.255.240 area 15 ! LAN PMU
!
!
!
!
! ################################################
! Avalaible Routing Multicast for LAN EDA
! ################################################
!
ip multicast-routing
!
interface GigabitEthernet0/0
ip pim sparse-mode
!
interface GigabitEthernet0/1.500
ip pim sparse-mode
!
interface Serial0/1/0.36 point-to-point
ip pim sparse-mode
!
interface GigabitEthernet0/1.134
ip pim sparse-mode
ip igmp join-group 224.0.224.1
!
ip pim rp-address 173.17.2.1 VALID_GROUP
!
ip access-list standard VALID_GROUP
permit 224.0.224.1
!
!
!
router ospf 1
network 134.1.192.32 255.255.255.240 area 15 ! LAN PMU
!
!
!
!
! ################################################
! Avalaible Routing Multicast for LAN EDA
! ################################################
!
ip multicast-routing
!
interface GigabitEthernet0/0
ip pim sparse-mode
!
interface GigabitEthernet0/1.500
ip pim sparse-mode
!
interface Serial0/1/0.39 point-to-point
ip pim sparse-mode
!
interface GigabitEthernet0/1.134
ip pim sparse-mode
ip igmp join-group 224.0.224.1
!
ip pim rp-address 173.17.2.1 VALID_GROUP
!
ip access-list standard VALID_GROUP
permit 224.0.224.1
I did some tests simulated and I think I figured out why is assigned an IP address instead of another.
Given that the interface Tunnel0 is created when you type the command "ip pim rp-address 173.17.2.1 VALID_GROUP", in the tests I've done, I Tunnel0 Bind to the IP address associated with the FastEthernet0/0.
R-SCTI-PADRICIANO-1#sh ip int b
>> Interface IP-Address OK? Method Status Protocol
>> FastEthernet0/0 173.27.200.22 YES manual up up
>> FastEthernet0/1 unassigned YES manual up up
>> FastEthernet0/1.20 172.27.195.118 YES manual up up
>> FastEthernet0/1.30 172.27.230.100 YES manual up up
>> FastEthernet0/1.31 173.27.254.118 YES manual up up
>> FastEthernet0/1.32 173.27.216.28 YES manual up up
>> FastEthernet0/1.134 134.1.192.33 YES manual up up
>> FastEthernet0/1.500 172.27.250.37 YES manual up up
>> Serial1/0 unassigned YES unset administratively down down
>> Serial1/1 unassigned YES unset administratively down down
>> Serial1/2 unassigned YES unset administratively down down
>> Serial1/3 unassigned YES unset administratively down down
>> Loopback0 172.27.254.10 YES manual up up
>> Tunnel0 173.27.200.22 YES unset up down
R-SCTI-PADRICIANO-1#conf t
>> R-SCTI-PADRICIANO-1(config)#int f0/0
>> R-SCTI-PADRICIANO-1(config-if)#sh
>> *Feb 6 16:09:31.439 CET: %LINK-5-CHANGED: Interface FastEthernet0/0, changed state to administratively down
>> *Feb 6 16:09:32.439 CET: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to down
>> R-SCTI-PADRICIANO-1(config-if)#do sh ip int b
>> Interface IP-Address OK? Method Status Protocol
>> FastEthernet0/0 173.27.200.22 YES manual administratively down down
>> FastEthernet0/1 unassigned YES manual up up
>> FastEthernet0/1.20 172.27.195.118 YES manual up up
>> FastEthernet0/1.30 172.27.230.100 YES manual up up
>> FastEthernet0/1.31 173.27.254.118 YES manual up up
>> FastEthernet0/1.32 173.27.216.28 YES manual up up
>> FastEthernet0/1.134 134.1.192.33 YES manual up up
>> FastEthernet0/1.500 172.27.250.37 YES manual up up
>> Serial1/0 unassigned YES unset administratively down down
>> Serial1/1 unassigned YES unset administratively down down
>> Serial1/2 unassigned YES unset administratively down down
>> Serial1/3 unassigned YES unset administratively down down
>> Loopback0 172.27.254.10 YES manual up up
>> Tunnel0 172.27.250.37 YES unset up down
>>
>> IP address Tunnel0 = IP address FastEthernet0/1.500
