routeprotocol.com

CCNP Enterprise Core (350-401)

  • PIM Distribution Trees

    A multicast router will create a distribution tree that will define the path multicast traffic follows to reach receiver devices. There are two types of multicast distribution trees known as source trees. They are also known as shortest path trees, SPTs and shared trees. Source Tree A source tree is a multicast distribution tree where…

  • PIM – Protocol Independent Multicast

    Hosts utilise IGMP to join a multicast group, this works perfectly fine when the router that the membership join request gets sent to also hosts the subnet that sends out the multicast traffic flows. If the receiving host and the multicast source router are several hops apart, routing between the routers will need to be…

  • IGMP Snooping

    IGMP snooping is a method that allows switches to only send traffic to interested receivers of multicast packet streams. IGMP snooping helps switches to optimise forwarding and minimise flooding of multicast streams to all connected ports on their device. Typically with unicast traffic, switches learn about MAC addresses and where they belong to by inspecting…

  • IGMP Version 3

    When a host in IGMPv2 sends a membership report to join a multicast group, it does not specify the source that it would like to receive the multicast traffic from. IGMPv3 is an extension on top of IGMPv2 that adds support for the multicast source filtering, giving the host a choice to pick the source…

  • IGMP Version 2

    IGMP Version 2 uses a message format 32 bits in size, with three fields. The first 8 bits are the type, the next 8 bits are the max response time, and the final 16 bits are a checksum. This message is encapsulated inside of an IP packet with a protocol number of 2. The message…

  • Internet Group Management Protocol (IGMP)

    IGMP, Internet Group Management Protocol, is a protocol that hosts/receivers use to join multicast groups and begin receive the groups multicast traffic. In order for Internet Group Management Protocol to work correctly, both the hosts and the router must support IGMP. When the host wishes to receive a multicast stream, it advertises to the router…

  • Multicast: Layer 2 Addresses

    On older network interface cards, the hardware would only traffic destined to it’s burned in MAC address or the broadcast MAC address. Multicast on Layer 2 was designed with this in mind. Every multicast group IP address is mapped to a special MAC address that will allow network interface cards to identify multicast packets to…

  • Multicast Addressing

    The Internet Assigned Number Authority (IANA) assigned IP Class D space for multicast addressing – 224.0.0.0/4 This includes the range 224.0.0.0 to 239.255.255.255 Address Range Description 224.0.0.0 – 224.0.0.255 Local Network Control 224.0.1.0 – 224.0.1.255 Internetwork Control 224.0.2.0 – 224.0.255.255 Ad-hoc 1 224.1.0.0 – 224.1.255.255 Reserved 224.2.0.0 – 224.2.255.255 SDP/SAP 224.3.0.0 – 224.4.255.255 Ad-hoc 2…

  • Multicast

    IP communication between hosts uses one of three transmission methods: unicast, broadcast, or multicast. If there is a group of five different hosts, and three wish to view an identical video stream, multicast would be the best transmission method to be used. Unicast would result in inefficiency by using triple the bandwidth that would be…

  • BGP Path Attributes: Lowest Neighbour Address

    The last deciding factor on choosing a best path is to select the path that comes from the lowest BGP neighbour address. Only iBGP applies here as eBGP would of been determined using the oldest received path earlier in the chain.