CCNP CCIE Complete

Membership Query The Query message is used to determine if there are any extant members in a particular group. Two types of query exist: Group-Specific Queries and Group-and-Source-Specific Queries. Group-Specific Queries If a host receives an IGMPv3 Group-Specific Query in ... [full story]

Internet Group Management Protocol Version 3 (IGMPv3) Multicasting is a rapidly evolving world of multicast traffic flows. No surprise, then, that version 2 of IGMP is not without its own flaws. Known problems with IGMPv2 (which were not obvious in ... [full story]

IGMPv2 Leave process Internet Group Management Protocol Version 3 (IGMPv3) Multicasting is a rapidly evolving world of multicast traffic flows. No surprise, then, that version 2 of IGMP is not without its own flaws. Known problems with IGMPv2 (which were ... [full story]

IGMPv2 Leave Process IGMPv2 implemented the capability for hosts to remove themselves from the multicast group immediately (in a matter of seconds) instead of the router having to wait up to three minutes. The process is known as the IGMP ... [full story]

General and Group-Specific Query Processes One enhancement that was made to IGMPv2 processes was the creation of a new query type. The Membership Query, as it was called in IGMPv1, was renamed General Queries, and the new type is Group-Specific ... [full story]

Internet Group Management Protocol Version 2 (IGMPv2) As with any software revision, features are made better. Defined by RFC 2236, Internet Group Management Protocol version 2 (IGMPv2) provides the same functionality as version 1 did, but with a few enhancements: ... [full story]

Leave Process Withdrawal from a group is not initiated by the host, as one would imagine. The router hosts a timer that is reset every time a response is received from a host on the subnet. The timer runs for ... [full story]

Unsolicited join requests Unsolicited report for 224.2.127.254 Unsolicited report for 224.2.145.155 t = 0 : Membership query sent t = 0 : No reports sent by a or b t = 24 : B sent a report to r1 for ... [full story]

Join Process The other processes are joining and leaving multicast groups. Both of these processes are quite simple and straightforward. You understand how interfaces are maintained in an active state through Membership Queries. The query process runs only every 60 ... [full story]

IGMPv1 Query process Report 224.2.168.242 Report 224.2.127.254 Report 224.2.168.242 224.2.168.242 224.2.168.242 224.2.168.242 (All hosts 224.0.0.1) (All hosts 224.0.0.1) Report 224.2.155.145 Report 224.2.168.242 #4a #5a #3a #5b #2b #4b #3b #2a #1 #1 E0 E1 Host B Host A Host C ... [full story]

Membership Query Process One important process is the IGMP Query process , which is kindred to a keepalive procedure. Because the router needs to keep tabs on which multicast groups need to remain active, or be made active or inactive, ... [full story]

Internet Group Management Protocol Version 1 (IGMPv1) As the name indicates, Internet Group Management Protocol version 1 (IGMPv1) was the first version of the protocol. It was a result of RFC 1112. The purpose of this protocol is to enable ... [full story]

Subscribing and Maintaining Groups For multicast traffic to reach a host, that host must be running an application that sends a request to a multicast-enabled router informing the router that it wishes to receive data belonging to the specified multicast ... [full story]

Managing Multicast in an Internetwork As a user on the network, you can understand that spam is not something that is managed by a systems administrator, whereas valid mailing lists require maintenance to keep a current list of valid subscribers. ... [full story]

Multicast addressing overlap The problem this creates is that the end host must now process packets from both multicast groups even though it is interested only in data from 224.2.127.254. This causes unwanted overhead and processor interrupts on the host ... [full story]

Layer 3 to Layer 2 Overlap By the time you’ve done a few of these conversions, you’ll notice that there is a problem with this conversion scheme. By not using all available bits for a Class D address, you cannot ... [full story]

IP multicast mapped to MAC multicast 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0 1 1 1 1 0 0 1 1 1 0 x x x x x ... [full story]

Mapping IP Multicast to Ethernet Multicast addressing began on MAC addresses. Growth needs required that there be a way to use multicast across routers instead of limiting it to the physical segment where hosts were located. In regular unicast, MAC ... [full story]

Each address range is managed by the Internet Address Number Authority (IANA). Due to the limited number of multicast addresses, there are very strict requirements for new assignments within this address space. The 239.0.0.0–239.255.255.255 range is equivalent in purpose to ... [full story]

IP Multicast Reserved Addresses Address Purpose Reserved Category 224.0.0.0–224.0.0.18 Use by network protocols Local-link 224.0.0.1 All hosts Local-link 224.0.0.2 All routers Local-link 224.0.0.19–224.0.0.255 Unassigned Local-link 224.0.1.0–224.0.1.255 Multicast applications Misc. applications 224.0.1.1 NTP Misc. applications 224.0.1.8 NIS+ Misc. applications 224.0.1.39 Cisco-RP-Announce ... [full story]

Using Multicast Addressing Just as with mailing lists, there are several different groups that users or applications can subscribe to. The range of multicast addresses starts with 224.0.0.0 and goes through 239.255.255.255. As you can see, this range of addresses ... [full story]

Multicast communication The key to multicast is the addressing structure. This is key because all communication is based on addressing. In unicast communication, there is a unique address for every host on a network. In broadcast communication, a global address ... [full story]

Multicast Multicast is a different beast entirely. At first glance, it appears to be a hybrid of unicast and broadcast communication, but that isn’t quite accurate. Multicast does allow point-to-multipoint communication, which is similar to broadcasts, but it happens in ... [full story]

Broadcast message on a network Server 172.16.1.0/24 Host C Host A Host B Host X Server 172.16.1.0/24 Host C Host X Host A Host B Multicast Overview 589 A good example of a broadcast message is an Address Resolution Protocol ... [full story]

Broadcast Now that you have a good understanding of unicast, we can discuss the principle of broadcast communication on networks. Whereas unicast messages target a single host on a network (unicast communication can be compared to sending an e-mail to ... [full story]

Unicast communication The unicast process occurs between two hosts only. A single destination address is used to ensure that data is sent to only one host. This could be client-to-server, server-to-client, or peerto- peer. It doesn’t matter, so long as ... [full story]

Unicast Unicast is used for direct host-to-host communication. When the layer 3 protocol data unit (PDU, or packet) is formed, two layer 3 IP addresses are added to the IP header. These are the source and destination IP addresses. They ... [full story]

Multicast Overview Just as blue, yellow, and red are different and each has its own place within the spectrum of visible light, unicast, broadcast, and multicast are different in that each is used to achieve a specific purpose or fulfill ... [full story]

Understanding and Configuring Multicast Operation THE CCNP EXAM TOPICS COVERED IN THIS CHAPTER INCLUDE THE FOLLOWING:
Describe the functionality of CGMP.
Describe how switches facilitate multicast traffic.
Translate multicast addresses into MAC addresses.
Enable CGMP on ... [full story]

CEF forwarding process Configuring CEF To configure CEF on a 3550 switch, you first have to enable IP routing. Remember that because this is a multilayer switch, only the layer 2 switching processes are enabled by default, to maintain the ... [full story]

Optimum switching tree The CEF Forwarding Process At last we come to CEF. CEF maintains two separate but related tables: the forwarding table and the adjacency table. The forwarding table contains routing information, and the adjacency table contains layer 2 ... [full story]

Optimum Switching Optimum switching also relies on a caching mechanism, but there are important differences from fast switching. The first difference is in the operation of the tree. Instead of a binary tree, with each level being a single comparison ... [full story]