Multicast notes:
- class D - 224.0.0.0/4 (224.0.0.0 – 239.255.255.255)
- reserved (like rfc 1918) – 224.0.0.0/24 (224.0.0.0 -224.0.0.255)
- Administratively Scoped Block – 239.0.0.0-239.255.255.255
- hello’s are sent every 30 sec to 224.0.0.13
- loopback – ip ospf point-to-point for RPF check
- (S,G) source tree / shortest path tree / source
(*,G) shared tree / any source - holdtime = 3.5x the hello
- highest IP wins DR
- lowest IP wins designated querier
- rp-address (unicast) must be advertised in unicast IGP
- mtrace to group address to see the reverse path
- traffic is always sent to the group address, never from.
- the source ip is always a unicast ip address, never a mcast address.
- igmp = router to client (automatically enabled with PIM)
- pim = router to router ( relies on unicast routing domain, do make sure you have full igp connectivity)
- sparse-mode – explicit join ( no traffic unless uyou request it) need’s an RP.
- dense-mode – implicit join (gets all traffic unlexx you don’t want it), flood and prune
- enabe mcast = ip multicast-routing (distributed on 3560)
- (*,G) don’t care about the source. (S,G) knows the source
- incoming null / outgoing null – does not know the source.
- Enable PIM on the shortest path to the Rp or you will get RFP failures.
- switching from a shared tree (*,G) to a shortest path tree (S,G) = SPT switchover
- if theRPF fails the packet is dropped.
- ping
- sh ip mroute count
- debup ip packet
- ip mroute to rpf failure interface.
- RP
- auto -rp
- ip pim sparse-dense
- ip pim send-rp-announce loopback scope 16
ip pim send-rp-discovery scope 16 - p pim autorp listener – use when you have sparse-mode interfaces/all sparse mode router.
- fallback to dense mode is he default, to prevent it use : ip pim dm-fallback.
- 224.0.1.39 (announce) and 224.0.1.40(discovery)
- Candidate RPs advertize their willingness to be an RP via “RP-announcement” messages. These messages are periodically sent to a reserved well-known group 224.0.1.39 (CISCO-RP-ANNOUNCE).
- RP mapping agents join group 224.0.1.39 and map the RPs to the associated groups. The RP mapping agents advertise the authoritative RP-mappings to another well-known group address 224.0.1.40 (CISCO-RP-DISCOVERY). All PIM routers join 224.0.1.40 and store the RP-mappings in their private cache.
- deny statements – the groul ill be negatively cached and run int dense mode.
- control updates with ip multicast boundry
- For the Auto-RP with Multiple RPs scenario, no load balancing is provided, and, when an RP changes, convergence is normally on the order of 3 minutes.
- Bootstrap router
- ip pim sparse-mode
ip pim bsr-candidate
ip pim rp-candidate - use hash to load balance
- multiples overlapping RP’s = highest priority wins
- control updates with ip pim bsr-border
- ip pim sparse-mode
- auto -rp
- static – ip pim rp-address – you need this on all the mcast devices.
- override – will override AUTORP or BSR rp mappings.
- dynamic – auto-rp (cisco prorietary) or BSR
- ip pim NBMA = use on hub in a FR network, to bypass split-horizon behavior.
- GRE is the duct tape of routing!!! makse your tunnel interfaces passive.
- troubleshootin mcast:
- 1 int s0/0 no ip mroute-cache -2- debup ip mpacket
- debup ip pim
- sh ip pim nei | rp | rp mapping | interface
- sh ip pin int f0/0 detail
- debup ip pim auto-rp <-shows you what RP is filtered.
- sh run | in ip pim|int
- keyword search under ip pim command reference
- ip helper-map
- convert from mcast group to broadcast
- ip multi helper-map 224.1.1.1 150.100.200.255 111
- acecss-list 111 oer udp host 150.100.255.1 a eq 39000
- convert from mcast group to broadcast
- anycast – 2 RP’s with the same IP address’
- r1
int lo0
ip add 10.0.0.1 255.255.255.255
int lo1
ip add 10.1.1.1 255.255.255.255
ip msdp peer 10.1.1.2 connect-sour loo1
ip msdp originator-id loo1
ip pim rp-address 1.1.1.1 [acl]
r2
int lo0
ip add 10.0.0.1 255.255.255.255
int lo1
ip add 10.1.1.2 255.255.255.255
ip msdp peer 10.1.1.1 connect-sour loo1
ip msdp originator-id loo1
ip pim rp-address 1.1.1.1 [acl]
No comments:
Post a Comment