Hello Guys,

When I was studying Multicast for BSCI I came across some questions that ask for certain multicast addresses associated with their applications. Here is a summary table of the relevant addresses I know I have over my studies, combined with some demand issues in the study.

Reference:

- IANA, IPv4 Multicast Addresses <http://www.iana.org/assignments/multicast-addresses/>. 23/maio/2009 in Access.

A big hug and success to all.

Maurício Bento Ghem

Hello Guys,
I did this summary on the most important of IPv6 to be didactic, comprehensive and objective. The level of coverage of this summary would be midway between BSCI and CCNA certifications. Below.

IPv6

- We added several features compared to IPv4, such as 128 bits for addressing (IPv4 only 32), security (through extension headers), techniques to transition from IPv4 to IPv6, QOS embebbed (direct the header), Autoconfiguration ( allows a host to obtain an IP address without having to run DHCP on the network) and IP mobility.
- The IPv6 address has 128 bits and is divided into 8 ’sextet’, each with 16 bits.
- The Header (including the source and destination IP) has 320 bits, without the extensions - below.

- IPv6 does not have the checksum field (and not the place), considering that the control of errors of lower layers is reliable.
- IPv6 USA not broadcast, but multicasting. A broadcast can be simulated by sending a multicast address to the All-nodes, link-local scope (FF02:: 1).
- Loopback Address -:: 1 / 128 (IPv4 = 127.0.0.1). Address default-route -: 0 / 0 (IPv4 = 0.0.0.0 / 0).
- EUI-64: format derived from the MAC-address used to assign addresses Link-Local. You get the MAC address (48 bits), the hexadecimal number FFFE inserted in the middle of it and changed the first 2 bits (from 00 to 20), so the MAC 00eb.1234.3322 in EUI-64 format would be: 02eb: 12ff: fe34: 3322. Finally, adding the prefix for link-local addresses would: FE80:: 02eb: 12ff: fe34: 3322.
- Types of IPv6 addresses:

• Global Unicast: Identifies a single host on the Internet. Prefixes will be assigned to each organization (48 bits or less), as seen in the picture. The IANA defines the prefix for these prefixes like 2000:: / 3.
• Link-Local: Each interface receives one of these addresses. It is used for the devices on the same network to communicate without having to use the Global Unicast address. Use the prefix FE80:: / 10 + the EUI-64 format.
• Site-local. Single address within the scope of the organization, not routable on the Internet. Prefix: FEC0:: / 10.

- Multicast: Identified by prefix FF00:: / 8. The next 4 bits are flags, and the other 4 next define the scope of Multicast (shown below). Beside, a diagram of the range of scopes.

• 1 = Interface-local.
• 2 = link-local.
• 5 = site-local.
• 8 = Organization-local.
• E = Global.

- Anycast: A Global Unicast address assigned to more than one device, set it as anycast. Has as its route to the nearest anycast device. See below.

- IPv6 Hosts must meet at least the following addresses:

• Global Unicast and Anycast (2000:: / 3)
• Link-local (FE80:: / 10, by Autoconfiguration
• Loopback (:: 1 / 128)
• Multicast all-nodes (FF01:: 1 and FF02:: 1)
• Another group multicast assigned.

- Routers, and this answer should also respond in address:

• Anycast address of the subnet (the subnet address with the Interface ID - Host address - set to 0)
• All-Multicast routers (FF01:: 2, FF02:: 2, FF05:: 2)
• Groups defined by multicast routing protocols (if applicable). EIGRP for IPv6: FF02:: 10, OSPFv3: FF02:: 5 (all routers) and FF02:: 6 (only DR and BDR).

- The main forms of transition from IPv4 to IPv6 can be made through the Dual Stack (running both IPv4 and IPv6 to no longer have need for IPv4) and tunneling (encapsulate the IPv6 packet within an IPv4 packet - figure). For the tunneling is expected the prefix 2002:: / 16.

References:

- CCNP BSCI Official Exam Certification Guide 4th edition, por Brent Stewart. CiscoPress

- CCNA 4.1 Guia Completo de Estudo, por Marco Filippetti. Visual Books

- CertProject, imagem do header IPv6.

- Cisco IOS IPv6 Multicast Introduction - Very good.

- RFC 3513 Internet Protocol Version 6 (IPv6) Addressing.

I would pay special support to all who will make sure during the month of June.

A big hug,

Maurício Bento Ghem.

Hello Guys,

The blog following the flow of the author is also acquiring material for CCNP certification. Yesterday, continuing with the study Multicast finish my study and now started on the IPv6.

I contribute a laboratory that helped me in understanding the protocol PIM (Protocol independent Multicast) which is the protocol used in BSCI to create the routing tables multicast.

As there are two types of configuration of PIM, dense-mode and Sparse-mode, two laboratories were different and they both use the same topology (see Figure).

The laboratories are TXT files that are the initial settings. The settings are stored in NVRAM of router is the final, to be made tests. If you want to configure from scratch, feel at home. Below I provide them for download and use, pointing out that the router used is the 3600 with IOS 12.3 release 15 and download its IOS can be made in this link, paste IOS - Dynamips.

Download the laboratories can be made below:

Lab Multicast PIM-Dense Mode

Lab Multicast PIM Sparse-mode

Cheers,

Maurício.