multicats flashcards v2
In SM, join and prune information expires in 5 minutes and is deleted, so periodic refresh is needed for maintenance
False, in 3 minutes
What command to display the mroute in XR
show mrib ipv4
S,G: ___flag indicates entry created as a result of the SPT threshold being violated and Switchover having been executed S,G: ___ flag indicates traffic received successfully via SPT
J, T
What are the configuration forms of the RP
Static (Does not allow redundancy) Dynamic: – Auto RP — Candidate RP announces via 224.0.1.39 (Mapping agents) — Mapping agent announces via RP via 224.0.1.40 (all routers) — Routers cannot send multicast in SM without an RP —– Sparse dense mode —– Auto RP Listener
When enabling PIM all routers automatically join the group 224.0.1.40 to receive updates from the mapping agent that has the function of informing which is the RP
224.0.1.40
How does the Auto RP listener work
As routers in sparse mode cannot transmit multicast without an RP, there is a chicken and egg problem, solved by the auto-RP listener. The Auto RP listener forces the network to operate in dense mode specifically for the groups of the auto RP election process. 224.0.1.39 (auto RP candidate announcement) 224.0.1.40 (auto RP announcement)
Auto RP Candidate A candidate sends messages to the group 224.0.1.39 in dense mode every___ secs announcing itself Hold time___ secs
60 secs, 180 secs
The ____ _______ receives the candidacies, elects an RP, and informs other routers via _________ in ____ mode
mapping agent, 224.0.1.40, dense
What are the configurations for Candidate RP?
ip pim send-rp-announce interface router pim auto-rp candidate-rp interface
What are the configurations for Mapping Agent?
ip pim send-rp-discovery Router pim auto-rp mapping-agent interface
__________ _________ ________ is a datagram delivery model that best suits one-to-many applications
Source Specific Multicast – SSM
Has only (S,G) states Does not use shared tree, only SPT whose root is the source Senders inform which sources they want to receive the flow from No need for MSDP for multidomain flows There is a specific range for use in SPT SSM: 232.0.0.0/8 The LHR can send a join message immediately towards the source as the sender has already informed which source it wants to receive the flow from
Source Specific Multicast – SSM
Range SSM
232.0.0.0/8
BIDI PIM eliminates _____ states
S,G
PIM BIDI The __________ __________ Router with the lowest IGP unicast cost to the RP Responsible for forwarding flow Downstream towards the receiver Upstream towards the RP The use of DF eliminates loops
designated Forwarder
In BIDI PIM all traffic flows via RP
True
Consider SM already activated, what commands are needed to activate PIM BIDI
ip pim bidir-enable Static RP configuration ip pim rp-address x.x.x.x bidir Dynamic RP configuration ip pim send-announce x.x.x.x bidir
______ —Static Allocation of ____ The RFC 2770 proposes the use of the range _____ embedding the AS in the second and third octet, so each AS would have its unique multicast range
GLOP 233/8
The_____ is basically a protocol that allows 2 PIM SM domains to behave as one, all normal SM intradomain operation is extended to interdomain. A scalability problem is that AS messages are sent every __ sec, new sources may not be used within this interval ____ operates only with PIM SM
MSDP, 60 secs
MSDP establishes TCP sessions on port ___
639
IPv6 Multicast address uses the range _____
FF00::/8
What is the equivalent function to IPv4 in the IPv6 Solicited-Node Multicast Address Format
ARP
Cisco does not support PIM Dense mode for IPv6, other vendors do
True
IPv6 uses a single RP for interdomain multicast
True
In IPv6 the _____________________ is the protocol used for the Receiver / Multicast Listener to report interest in joining a particular multicast group
Multicast Listener Discovery - MDL
In IPv6 the ______________ allows the use of unique multicast prefixes without the need for specific prefixes for this purpose delegated by IANA
Embedded RP
Cisco Auto RP is normally supported for IPv6
True
MLDv2 protocol is equivalent to IGMPv3
True, supports SSM
The FHR performs the register every 3 minutes in flood and prune like to the RP
True
If there are no clients registered in the RP, upon receiving a register message it should ignore it
False, the RP will originate a Register Stop message
Range mac address IPv6 Multicast
33:33:xx:xx:xx:xx
Consider the address below and point out what should be the mapped multicast mac address: FF0E:AAAA:BBBB:CCCC:DDDD:EEEE:AAAA:BBBB
3333.AAAA.BBBB Mapping: Mac starts with 3333 + last 32 bits of the destination ipv6
Sparse mode operation: Neighbor discovery ___ and election of ___ Discovery of __ Inform RP about the _____ Inform RP about the _____
PIM, DR, RP, Senders, 4 Receivers
Sparse mode operation: Build Source tree from _____ to the RP Build Shared tree from _____ to the _____ Source must join the _______ tree Source must leave the _______ tree
Shortest Path tree
RP learns about senders via _______ register messages RP learns about receivers via ______ messages
PIM Register (S,G), PIM Join (*,G)
Consider a LAN with multiple LHR or FHR, which router should send PIM messages to the RP?
the DR
Upon receiving an IGMP Report message, the LHR originates _______ ______ messages in the reverse path towards the RP, at this point all intermediate routers create _______ entries, forming the _______ tree
PIM Join, (*,G), Shared
Criterion for election of the DR? In case of a tie?
Highest priority wins, highest IP address
What does the designated querier do?
In the IGMP domain: If there are two LHR One must be elected Conducts a query on hosts still interested in multicast flow
L2 table that contains hosts interested in multicast flows
IGMP snooping table
Criterion for election of IGMP Querier Routers
Lowest IP
