I'm in my final preparation of my CCNP certification BSCI exam, my exam is schedule to next Friday, so rapid answer will be appreciated. For final preparation I had buy How2Pass test exam to test my knowledge before going to the test center. I find I had some difficulties with IP multicast subject about troobleshooting.....
in the following question (see attach filed ng43.zip)
I answer to this question by :
The RP for this network ==> because the RPF ip address is set to 0.0.0.0 for the entry (*,184.108.40.206) the local IP address of this router is : 10.127.0.7 base on RP information
The multicast source of this router is serial 1/4 interface ==> the incomming interface is serial 1/4 for the entry (172.16.8.1,220.127.116.11) and the source multicast server will be at the IP address 172.16.8.1 and the next hop to reach this IP address is 10.139.16.130 base on RPF nbr information in this entry.
Because I did not sucessfully answer this question on the first time I also read the link provide on Cisco website for explanation :
which after reading help me to understand some point, but also raised some question.....
in the following output
The following is sample output from the show ip mroute command for a router operating in sparse mode:Router# show ip mrouteIP Multicast Routing TableFlags: D - Dense, S - Sparse, C - Connected, L - Local, P - PrunedR - RP-bit set, F - Register flag, T - SPT-bit setTimers: Uptime/ExpiresInterface state: Interface, Next-Hop, State/Mode(*, 18.104.22.168), uptime 5:29:15, RP is 22.214.171.124, flags: SCIncoming interface: Tunnel0, RPF neighbor 10.3.35.1, DvmrpOutgoing interface list:Ethernet0, Forward/Sparse, 5:29:15/0:02:57(126.96.36.199/24, 188.8.131.52), uptime 5:29:15, expires 0:02:59, flags: CIncoming interface: Tunnel0, RPF neighbor 10.3.35.1Outgoing interface list:Ethernet0, Forward/Sparse, 5:29:15/0:02:57
my understanding the RP for the group 184.108.40.206 is 220.127.116.11 and the next hop to RP is 10.3.35.1. But in the second entry if the group 18.104.22.168 is used in sparse mode why is it not appear the R flag to tell this entry is pointing toward the RP like it is explain in table 45 in the same pages
R - RP-bit set
Indicates that the (S, G) entry is pointing toward the rendezvous point (RP). The RP is typically a prune state along the shared tree for a particular source.
also in the table 45 I would like understand the following :
Address of the rendezvous point router. For routers and access servers operating in sparse mode, this address is always 0.0.0.0.
Base on my understanding the RP this entry will on the IP address of the RP in sparse mode, in dense mode because theire is no RP the value will be set to 0..... is had in error here ??
also in the following I find some contradiction base on what I had understand :
Someone can help me to understand !
Thanks a lot !