IPV6 Routing – some technical background

Topics
- IPv6 Fragmentation
- Configurable MTU
- Path MTU Discovery
- ICMP v6

QoS:
- Classification on TC and dot1p
- Remarking of dot1p
- Remarking of TC based on FC


RFCs:
- RFC 2460 Internet Protocol, Version 6 (IPv6) Specification
- RFC 2461 Neighbor Discovery for IPv6
- RFC 2462 IPv6 Stateless Address Auto configuration
- RFC 2463 Internet Control Message Protocol (ICMPv6) for the IP v6 specification
- RFC 2464 Transmission of IPv6 Packets over Ethernet Networks
- RFC 3315 Dynamic Host Configuration Protocol for IPv6 (Relay Agent)
- RFC 3587 IPv6 Global Unicast Address Format
- RFC 4007 IPv6 Scoped Address Architecture
- RFC 4193 Unique Local IPv6 Unicast Addresses
- RFC 4291 IPv6 Addressing Architecture

L2VPN/VPLS-Martini and Kompella

Both Martini-draft and Kompella-draft addressed setting up of a Pseudowire emulation over MPLS in order to offer L2VPN services. These drafts were initial efforts to standardise L2VPN services.

Martini draft was named after a former Cisco employee Luca Martini. Martini draft uses LDP as signalling to setup L2VPN over MPLS backbone. The tradeoff of this draft was auto-discovery.

Kompella draft on the other hand uses BGP for both signalling and auto-discovery to establish fully-meshed pseudo wires (multipoint). Kompella-draft is named after author Keerti Kompella (Juniper Employee).

draft-martini and draft-kompella terms are used as labels for the two different L2VPN services methodologies (LDP Vs BGP for signaling). The actual drafts do not exist in IETF.

In dealing with multipoint-fully meshed topologies in edge routers, draft-martini suffered auto-discovery, to overcome aut0-discovery, it suffered configuration overhead. draft-Kompella claimed to be better scalable because of suto-discovery but with complex signalling whereas draft-martini leverages simplicity.

Martini draft was standardized under RFC 4096 . however it has since been superseded by the Pseudowire Emulation Edge to Edge (PWE3) Working Group specifications described in RFC 4447 and related documents. On the other hand draft-kompella is obsolete and was not standardized.

RFC 4664 - Framework for Layer 2 Virtual Private Networks (L2VPN), it describes the framework for L2VPNs (VPWS, VPLS and IPLS). This framework is intended to aid in standardizing protocols and mechanisms to support interoperable L2VPNs. Requirements for L2VPNs can be found in RFC 4665 – Service Requirements for Layer 2 Provider-Provisioned Virtual Private Networks.

All this was consolidated, and the L2VPN Working Group produced two separate documents, RFC 4761 and RFC 4762, both offered VPLS but using different signaling protocols:

Kireeti Kompella and Yakov Rekhter published “Virtual Private LAN Service (VPLS) Using BGP for Auto-discovery and Signaling” RFC 4761 in January 2007.

Marc Lasserre and Vach Kompella published “Virtual Private LAN Service (VPLS) Using Label Distribution Protocol (LDP) Signaling” RFC 4762 in January 2007.

L2VPN services for many vendors uses RFC 4762 -Martini ( with LDP) as a standard for example Alcatel 7450’s uses RFC 4762 as the standard

Taken From ciscotips.wordpress.com

Why Should I Care About IP Multicast?

Many applications used in modern networks require information (voice, video, or data) to be sent to multiple end stations. When only a few end stations are targeted, sending multiple copies of the same information through the network (unicast) causes no ill effects. However, as the number of targeted end stations increases, the harmful effects of duplicate packets become dramatic. Deploying applications such as streaming video, financial market data, and IP telephony-based Music On Hold without enabling network devices for multicast support can cause severe degradation to a network’s performance.

What Problems Need to Be Solved?

Multicasting requires methods to efficiently deploy and scale distributed group applications across the network. This is accomplished by using protocols that reduce the network load associated with sending the same data to multiple receivers and that alleviate the high host/router processing requirements for serving individual connections.

Internet Group Management 

Protocol (IGMP)

IGMP is a protocol that allows end stations to join what is known as a multicast group. Joining a multicast group can be thought of as like subscribing to a session or service where multicast is used. IGMP relies on Class D IP addresses to create multicast groups.When a multicast session begins, the host sends an IGMP message throughout the network to discover which end stations have joined the group. The host then sends traffic to all members of that multicast group. Routers “listen” to IGMP traffic and periodically send out queries to discover which groups are active or inactive on particular LANs. Routers communicate with each other using one or more protocols to build multicast routes for each group.

Multicast Distribution Trees

Multicast-capable routers create distribution trees that control the path that IP multicast traffic takes through the network to deliver traffic to all receivers. The two basic types of multicast distribution trees are source trees and shared trees. With source trees (also known as shortest-path trees), each source sends its data to each receiver using the most efficient path, as shown in the preceding figure. Source trees are optimized for latency but have higher memory requirements, because routers must keep track of all sources. With shared trees, shown in the following figure, the multicast data is sent to a common point in the network (known as the rendezvous point) before being sent to each receiver. In the figure, Router D serves as the rendezvous point, and all multicast data is routed through it. Shared trees require less memory in routers than source trees but may not always use the optimal path, which can resulting packet delivery latency

Layer 2 Multicast

A Layer 2 switch forwards all multicast traffic, which reduces network efficiency. Two methods, Cisco Group Management Protocol (CGMP) and IGMP snooping, were developed to mitigate this inefficient switch behavior. Cisco Group Management Protocol (CGMP) CGMP allowsCisco Catalyst switches to make Layer 2 forwarding decisions based on IGMP information. When configured on switches and routers, CGMP ensures that IP multicast traffic is delivered only to ports that are attached to interested receivers, or multicast routers. With CGMP running, any router receiving a multicast join message via a switch replies to the switch with a CGMP join message. This message allows Layer 2forwarding decisions to be made. IGMP Snooping IGMP snooping improves efficiency by enabling a Layer 2 switch to view Layer 3 information (IGMP) used to populate the unicast routing table. PIM uses this unicast routing information to perform the multicast forwarding function. Although PIM is called a multicast routing protocol, it actually uses the unicast routing table to perform the RPF check function instead of building a completely independent multicast routing table. It includes two different modes of behavior for dense and sparse traffic environments—dense mode and sparse mode:

• In PIM dense mode, the multicast router floods traffic messages out all ports (referred to as a “push” model). If a router has no hosts or downstream neighbors that are members of the group, a prune message is sent, telling the router not to flood message on a particular interface. Dense mode only uses source trees. Because of the flood and prune behavior, dense mode is not recommended.
• PIM sparse mode uses what is known as an “explicit join” model. In this model, traffic is only sent to hosts that explicitly ask to receive it. This is accomplished by sending a join message to the rendezvous point. An Anycast Rendezvous Point (RP) provides load balancing, redundancy, and fault tolerance by assigning the same IP address to multiple RPs within a PIM sparse mode network multicast domain. join/leave messages) sent between hosts and routers. When an IGMP host report is sent through a switch, the switch adds the host’s port number to the associated multicast table entry. When the switch hears the IGMP leave group message from a host, the switch removes the host’s table entry. IGMP requires a switch to examine all multicast packets and therefore should be implemented only on high-end switches. Multicast Forwarding In unicast routing, traffic is routed from the source to the destination host. The router scans its routing table for the destination address and then forwards a single copy of the unicast packet out the correct interface. In multicast forwarding, the source sends traffic to several hosts, represented by a multicast group address. The multicast router must determine which direction is the upstream direction (toward the source) and which one is the downstream direction (toward the hosts). When more than one downstream path exists, the best ones (toward the group address) are chosen. These paths may or may not be the same path that would be chosen for a unicast packet. This is called Reverse Path Forwarding (RPF). RPF is used to create loop-free distribution trees.

Taken From CiscoPress

Gus Dus Biography

Former President of Indonesia to 4 Abdurrahman Wahid, often called Gus Dur (born in Jombang, East Java, September 7, 1940, and died in Jakarta, December 30, 2009 at age 69 years).

He is a Muslim of Indonesian kiai and political leader who became president of Indonesia from 1999 to 2001. He succeeded President BJ Habibie after elected by the People's Consultative Assembly (MPR) 1999 election results.

Implementation of government assisted the National Unity Cabinet. Abdurrahman Wahid's presidency begins October 20, 1999 and ended after transmitted through the Special Session of the Assembly in 2001.

Right July 23, 2001, his leadership was replaced by Megawati Sukarnoputri after the mandate was revoked by the Assembly.

Abdurrahman Wahid is the former chairman of Tanfidziyah (executive body) NT NU and founder of the National Awakening Party (PKB).

Gus Dur was born on the 4th and 8th month of Islamic calendar year 1940 in the village of Denanyar, Jombang, East Java, from pair Wahid Hasyim and Solichah.

There is a belief that he was born on August 4, but the calendar used to mark the day of birth is the Islamic calendar, which means he was born on 4 Sha'ban, equal to September 7, 1940.

He was born with the name of Abdurrahman Addakhil. "Addakhil" means "The Conqueror". The word "Addakhil" is not well known, and changed the name of "Wahid", and then better known as Gus Dur calls.

"Gus" is a typical boarding school honor calls to a child kiai means "brother" or "mas".

Gus Dur is the first son of six children. Wahid was born from a very respectable family in the Muslim community of East Java. Grandfather from his father is KH Hasyim Asyari, founder of Nahdlatul Ulama (NU), while the maternal grandfather, KH Bisri Syansuri is the first boarding school teacher who teaches classes on women.

Father Gus Dur, the KH Wahid Hasyim, was involved in the nationalist movement and became Minister of Religious Affairs in 1949. Her mother, Mrs. Hj. Sholehah is the daughter of the founder of Pesantren Denanyar Jombang.

Gus Dur has openly stated that he had blood Tionghoa. He claimed descent from Tan Kim Han who is married to Tan A Lok, siblings Raden Patah (Tan Eng Hwa), founder of the Sultanate of Demak.

A Lok Tan and Tan Eng Hwa is a son of Princess Campa, daughter of a concubine China Raden Brawijaya V.

Tan Kim Han himself and based on studies of a French researcher, Louis-Charles Damais, identified as Sheik Abdul al-Shini Qodir the grave was found in the area Trowulan, East Java.

In 1944, Wahid moved from Jombang to Jakarta, where his father was elected as Chairman I Masyumi Party of Indonesia (Masyumi), an organization that stands with the support of the Japanese army occupied Indonesia.

After the declaration of Independence of Indonesia on August 17, 1945, Wahid returned to Jombang and remained there during the war of independence against the Dutch Indonesia.

At the end of 1949, Wahid moved to Jakarta, and his father was appointed as Minister of Religious Affairs. Abdurrahman Wahid studied in Jakarta, went to primary school before moving to KRIS SD Matraman Perwari. Wahid was also taught to read non-Muslim books, magazines, and newspapers by his father to expand his knowledge.

Wahid continued to live in Jakarta with his family although his father was not a minister of religion in 1952. In April 1953, Wahid's father died from a car accident.

Wahid continued education and in 1954, he entered the Junior Secondary School. In that year, he did not take the class. His mother then sent Gus Dur to Yogyakarta to continue his education. In 1957, after graduating from junior high, Wahid moved to Magelang to start education in pesantren Tegalrejo Muslims. He developed a reputation as a gifted student, completing the pesantren in two years (instead of four years). In 1959, Wahid moved to Tambakberas Pesantren in Jombang. There, while continuing his own education, Abdurrahman Wahid also received his first job as a teacher and later as head of the madrassa schools. Gus Dur is also employed as a journalist magazines like Horizon and Culture Magazine Jaya.

Overseas Education

In 1963, Wahid received a scholarship from the Ministry of Religious Affairs to study at Al Azhar University in Cairo, Egypt. He went to Egypt in November 1963.

Although he was proficient in Arabic, Wahid was told by the university that he had to take remedial classes before studying Islam and Arabic. Unable to provide proof that he has the ability Arabic, Wahid was forced to take remedial classes.

Abdurrahman Wahid began to enjoy living in Egypt in 1964, watching the European and American films, and also watch the football. Wahid was also involved with the Indonesian Student Association and became the association's magazine journalist.

At the end of the year, he successfully passed the remedial class was Arab. When he began his studies in Islam and Arabic in 1965, Wahid was disappointed. He has studied many of the materials provided and refuse to learn the methods used by the university.

In Egypt, Wahid was employed at the Embassy of Indonesia. By the time he worked, Movement event occurred 30 September 1965. Major General Suharto in Jakarta to handle the situation and the efforts made to eradicate communism.

As part of these efforts, the Indonesian Embassy in Egypt was ordered to conduct investigation on university students and provide reports on their political stance. This command is given to Wahid, who was assigned to write a report

But it can be said Wahid failed in Egypt. He did not agree with the method of education and work after the G 30 S / PKI which distracted him.

In 1966 he was told that he had to repeat. Wahid's tertiary education be saved through scholarship at the University of Baghdad. Wahid then was later moved to Iraq and enjoying his new environment.

Although he failed at first, Wahid quickly learned. He also continued his involvement in the Indonesian Students Association and also wrote the association's magazine.

After completing his education at the University of Baghdad in 1970, Wahid went to Holland to continue his education. Wahid wants to study at the University of Leiden, but was disappointed that his education at the University of Baghdad is less recognized. From the Netherlands, Wahid went to Germany and France before returning to Indonesia in 1971.

Early Career

Wahid returned to Jakarta and expect he will go abroad again to study at McGill University in Canada. It's kept himself busy by joining the Institute for Research, Education and Economic and Social Information (LP3ES), an organization comprised of Muslim intellectuals and progressive social democrats.

LP3ES then founded a magazine called Prisma, and Wahid became one of the main contributors to the magazine. In addition to working as a contributor LP3ES, Wahid was also around the pesantren and madrasah throughout Java.

At that time, boarding schools struggling to get funding from the government by adopting the government curriculum. Wahid was concerned that the conditions for the traditional values of the fade due to boarding school this change.

Wahid was also concerned with the poverty he saw the pesantren. At the same time when they persuaded the government boarding schools to adopt curricula, the government is also encouraging pesantren as agents of change and assist the government in the economic development of Indonesia. Wahid decided to drop plans for overseas studies in favor of developing the pesantren.

Abdurrahman Wahid then continued his career as a journalist, and writes for Tempo magazine and newspaper Kompas. The article was well received, and he began to develop a reputation as a social commentator.

With the popularity of that, he was invited to give lectures and seminars, forcing him to travel back and forth between Jakarta and Jombang, where Wahid lived with his family.

Despite having a successful career at that time, Gus Dur was still found it hard to live only from one source of livelihood, and he worked to earn additional income by selling peanuts and delivering ice to be used in her businesses Es Lilin.

In 1974 Wahid was an additional job as a teacher in Jombang in Pesantren Tambakberas, and soon developed a personal reputation. One year later, Wahid add jobs to become teachers Kitab Al Hikam.

In 1977, joined the University of Wahid Hasyim Asyari as Dean of the Faculty of Islamic practice and belief. Once again, Wahid was his job and the universities that want to Wahid to teach additional subjects such as pedagogy, Islamic Shari'a and missiology.

But the excess lead to resentment by some universities, and Wahid was blocked for teaching these subjects. While undertaking all these, Wahid was also addressed during Ramadan at the Muslim community in Jombang

NU
Zahid's family background and then quickly become meaningless. He will be asked to play an active role in running the NU. This ran contrary to the aspirations of Gus Dur in a public intellectual, and he had twice rejected offers to join the Religious Advisory Council of NU.
However, Wahid finally joined the board after his grandfather, Bisri Syansuri, gave him a third bid. Since taking this job, Wahid also choose to move from Jombang to Jakarta and stayed in the capital. As a member of the Religious Advisory Council, Wahid himself as a reformer to lead NU.
At Dur ituGus also got his first political experience. In legislative elections in 1982, Wahid was campaigning for the United Development Party (PPP), an Islamic party that was formed as a result of a merger of four Islamic parties, including NU.
Wahid said that the government interfere with the PPP campaign by arresting people like him. However, Wahid always managed to escape because they have relationships with important people, among them the General Benny Moerdani.

Election 1999 and the MPR

In June 1999, PKB participate in the legislative election arena. PKB won 12 percent of the vote, while the PDI-P won with 33 percent of the vote Raihan.
With the victory party, Megawati will win the election expected in the MPR president. However, the PDI-P does not have a full majority, thus forming an alliance with PKB.
In July, Amien Rais forming the Central Axis, a coalition of Islamic parties. Central Axis then began nominated Gus Dur as a third candidate in the presidential elections, and the commitment of PKB to the PDI-P began to change.
On October 7, 1999, Amien and Central Axis officially declared candidate Abdurrahman Wahid as president. On October 19, 1999, the Assembly rejected Habibie's accountability speech, and Habibie had to withdraw from the presidential election.
A few moments later Akbar Tanjung, Golkar Party Chairman and Chairman of the House declared that Golkar would support Gus Dur. On October 20, 1999, the Assembly re-assembled and began to elect a new president. Abdurrahman Wahid and Indonesia was elected as President of the 4th with 373 votes, while Megawati won only 313 votes.
Not happy because their candidates failed to win the election, Megawati supporters raged, Gus Dur and Megawati must realize that the elected vice president.
Once convinced, General Wiranto, to not participate in the election of vice-president and make the PKB supports Megawati, Gus Dur had managed to convince Megawati to participate.
On October 21, 1999 participate in the election of Megawati's vice president and defeated Hamzah Haz of the PPP