Hour 225: CCIE Mnemonics

Today, I started doing IPexperts labs and ordered the Paper version of their workbooks. My original plan was to start doing the CCIE lab preparation with INE but since CCIE v5 is coming soon, my new plan since is to start with IPexperts and then do the INE labs. Once the new technologies workbooks for v5 come out, I will most definitely switch completely to INE.

Now I would like to to talk a little bit about how I remembered most of the content for the CCIE Written; through mnemonics. Let me give you a description of what a mnemonics are and a list of the ones you will need for the CCIE Written. Continue reading

Hour 118: Auto RP vs BSR

Auto RP and BSR are two technologies used to dynamically create a group to RP mapping. Today I’ll do a review and compare both of these technologies and discuss which one you should use in your network. You can skip to the end of my post if you just want to read the overview.

Auto RP

Features:

  • Cisco Proprietary and uses PIMv1
  • If there is a group to RP mapping then the group is in SM, if not the group is in DM
  • [(INT)ip pim sparse-dense-mode] is required or [ip pim autorp listener] must be used if only sparse-mode is configured. Allows only groups 224.0.1.39 and 224.0.1.40. to be sent (the mode is still sparse, but those two dense mode groups are allowed)
  • Failed RP do not influence multicast traffic as long as last-hop router joined SPT
  • On NBMA if the Mapping Agent (MA) is on a spoke and needs to send mapping to another spoke, a GRE tunnel must be created between spokes with a static mroute (or RPF will fail). You can also enable NBMA mode on hub to avoid this.

Candidate RP:

  • Candidate-RP-Announce sent to MA 224.0.1.39 UDP/496
  • Used by routers to announce themselves as RP to the MA
  • Sent every 60 seconds with a holdtime  of 180 seconds.
  • [ip pim send-rp-announce <if> scope <ttl> %group-list <acl>% %interval <sec>%] Defines what RP’s the MA will receive
  • If ACL is not defined whole Multicast range is included. Do NOT use deny statement in C-RP ACLs. Also, only contiguous masks are allowed in group ACL.
  • Multiple Candidate-RP’s may exist for a Group. Highest IP is selected by Mapping agent Continue reading