Formação IPv6 - Maputo Encaminhamento Maputo 28 de Agosto de 2008 Carlos Friaças e Pedro Lorga

Encaminhamento

Agenda/Índice RIPng ISIS OSPFv3 Multiprotocolo BGP Conclusões

Encaminhamento Sistemas É uma questão a ter sempre em conta, de qualquer ponto da rede, ou sistema OS IPv4 IPv6 Cisco (IOS) show ip route show ipv6 route WinXP route print netsh interface ipv6 show route Linux /sbin/route /sbin/route –A inet6

Tipos de Protocolo Interno Externo RIPng (Routing Information Protocol) IS-IS (Intermediate System-Intermediate System) OSPFv3 (Open Shortest Path First) Externo BGP (Border Gateway Protocol) The routing protocols can be divided in two families, one aiming to provide for dynamic intra-domain routing, and other aiming to provide for the inter-domain routing. The protocols that support IPv6 are basically the ones that are used in the IPv4 world.

RIPng Igual ao funcionamento em IPv4 Baseado no RIPv2 Vector de Distância, máximo de 15 hops, split-horizon, … É um protocolo específico para IPv6 Num ambiente IPv4+IPv6 caso se escolha o RIP será necessário usar RIP (IPv4) e RIPng (IPv6) Like in IPv4 RIPng is one of a class of algorithms known as Distance Vector algorithms is based on RIPv2 RIPng is virtually useless except in certain very small domains. Different processes for ipv4 and ipv6

RIPng Funcionalidades relacionadas com IPv6 Usa IPv6 para comunicar Prefixo IPv6, endereço do próximo nó As mensagens de RIPng usam o endereço de multicast FF02::9 Like in IPv4 RIPng is one of a class of algorithms known as Distance Vector algorithms is based on RIPv2 RIPng is virtually useless except in certain very small domains. Different processes for ipv4 and ipv6

ISISv6 É um protocolo OSI Baseado em apenas dois níveis L2 = Backbone L1 = Stub L2L1= Interligação L2 e L1 Funciona sobre o protocolo CLNS Cada equipamento IS envia LSPs (Link State Packets) Envia informação via TLV’s (Tag/Length/values) Processo de estabelecimento de vizinhanças não muda Operação inalterada Intermediate System to Intermediate System is a link-state protocol routing decisions based on link states “State” is the description of the interface and its relationship to its neighboring devices [CLNS] - Connectionless Network Service The goal is to find the topology in the form of a shortest path tree (SPT) and them from the SPT build routing tables ISIS for IPv6 has exactly the same characteristics than on IPv4. Each router in the routing domain issues an LSP (link state packets) that contains information pertaining to that router. The LSP contains typed variable length data often referred to as TLVs (type-length-values) All comunication is made with LSP LSP componentes: who is my neigbor the interfaces’ addresses what’s the cost what are the protocols supported This is the best internal routing protocol in terms of scalability

ISISv6 Actualizações: Dois novos Tag/Length/Values (TLV) para IPv6 IPv6 Reachability IPv6 Interface Address Novo identificador da camada de rede IPv6 NLPID We extend the protocol with 2 new TLVs to carry information required to perform IPv6 routing. Two new TLV’s had to be created to suport IPv6: IPv6 Reachability – describes network reachability and contains IPv6 routing prefix and metrics IPv6 Interface Address – contains IPv6 interface addresses (128 bits) New network Layer Identifier IPv6 NLPID – this indicates that the router supports IPv6

OSPFv3 OSPFv3 = OSPF para IPv6 Baseado em OSPFv2 Topologia de uma área é invisível de fora dessa área O flooding de LSAs é feito por área O cálculo da SPF é realizado separadamente para cada área Todas as áreas têm de dispôr de uma ligação ao backbone It is a link-state protocol so, it makes the routing decisions based on the states of the links The state is the description of the interface and its relationship to its neighboring devices The communication is done via Link-State Advertisements (LSAs). A router's collection of LSA data is stored in a link-state database The database’s contents, when subjected to the Dijkstra algorithm, result in the creation of the OSPF routing table. Not as scalable as IS-IS.

OSPFv3 OSPFv3 é uma versão do protocolo exclusivamente IPv6 Numa rede de pilha dupla é necessário correr OSPF2 (IPv4) e OSPFv3 (IPv6) Há algum trabalho a ser desenvolvido no sentido de dotar o OSPFv3 de suporte IPv4. OSPFv3 is an IPv6-only routing protocol -> separate protocol from OSPFv2 (IPv4) In a dual-stack environment, running OSPF, you need OSPFv2 (IPv4) and OSPFv3 (IPv6) Implementing OSPFv3 for IPv6 expands on OSPFv2 to provide support for IPv6 routing prefixes. LSA Types for IPv6 Due to the fact that with IPv6 it is possible to configure many different IP addresses on one interface LSA types for OSPv3 differ from those in OSPFv2 for IPv4 Router LSAs (Type 1)—Describes the link state and costs of a router's links to the area.These LSAs are flooded within an area only. Network LSAs (Type 2)—Describes the link-state and cost information for all routers attached to the network. Interarea-prefix LSAs for ABRs (Type 3)—Advertises internal networks to routers in other areas (interarea routes) Interarea-router LSAs for ASBRs (Type 4)—Advertise the location of an ASBR. Autonomous system external LSAs (Type 5)—Redistributes routes from another AS, usually from a different routing protocol into OSPF. Link LSAs (Type 8)—Have local-link flooding scope and are never flooded beyond the link with which they are associated. Intra-Area-Prefix LSAs (Type 9)—A router can originate multiple intra-area-prefix LSAs for each router or transit network,

OSPFv3 Detalhes Corre directamente sobre IPv6 Distribui prefixos IPv6 Novos tipos de LSAs Os router-ids são endereços IPv4 Usa endereços Multicast Todos os routers (FF02::5) Todos os designated routers (FF02::6) OSPFv3 is an IPv6-only routing protocol -> separate protocol from OSPFv2 (IPv4) In a dual-stack environment, running OSPF, you need OSPFv2 (IPv4) and OSPFv3 (IPv6) Implementing OSPFv3 for IPv6 expands on OSPFv2 to provide support for IPv6 routing prefixes. LSA Types for IPv6 Due to the fact that with IPv6 it is possible to configure many different IP addresses on one interface LSA types for OSPv3 differ from those in OSPFv2 for IPv4 Router LSAs (Type 1)—Describes the link state and costs of a router's links to the area.These LSAs are flooded within an area only. Network LSAs (Type 2)—Describes the link-state and cost information for all routers attached to the network. Interarea-prefix LSAs for ABRs (Type 3)—Advertises internal networks to routers in other areas (interarea routes) Interarea-router LSAs for ASBRs (Type 4)—Advertise the location of an ASBR. Autonomous system external LSAs (Type 5)—Redistributes routes from another AS, usually from a different routing protocol into OSPF. Link LSAs (Type 8)—Have local-link flooding scope and are never flooded beyond the link with which they are associated. Intra-Area-Prefix LSAs (Type 9)—A router can originate multiple intra-area-prefix LSAs for each router or transit network,

BGP Multiprotocolo É um protocolo de encaminhamento EXTERIOR Interliga diferentes domínios de encaminhamento que têm políticas autónomas/independentes. Cada um possui um número de sistema autónomo (AS) Multiprotocol Border Gateway Protocol (BGP) for IPv6. BGP is an Exterior Gateway Protocol (EGP) used mainly to connect separate routing domains that contain independent routing policies (autonomous systems). This is the protocol that made the Internet come true in the 70s, and it has been adapted for IPv6. Multiprotocol BGP is an enhanced BGP that carries routing information for multiple network layer protocol address families: IPv6 unicast and multicast IPv4 unicast and multicast All BGP commands and routing policy capabilities can be used with multiprotocol BGP. The 6bone is/was a huge overlay test network based on tunnels, that allowed for extensive testing of IPv6’s extensions for BGP. The 6bone is intented to end by 6/6/2006.

BGP Multiprotocolo Transporta sequências de números de AS que ilustram caminhos Suporta as mesmas funcionalidades que o BGP para IPv4 Várias famílias de endereçamento: IPv4 unicast IPv4 multicast IPv6 unicast IPv6 multicast Multiprotocol Border Gateway Protocol (BGP) for IPv6. BGP is an Exterior Gateway Protocol (EGP) used mainly to connect separate routing domains that contain independent routing policies (autonomous systems). This is the protocol that made the Internet come true in the 70s, and it has been adapted for IPv6. Multiprotocol BGP is an enhanced BGP that carries routing information for multiple network layer protocol address families: IPv6 unicast and multicast IPv4 unicast and multicast All BGP commands and routing policy capabilities can be used with multiprotocol BGP. The 6bone is/was a huge overlay test network based on tunnels, that allowed for extensive testing of IPv6’s extensions for BGP. The 6bone is intented to end by 6/6/2006.

BGP Multiprotocolo O BGP4 transporta apenas três tipos de informação que são verdadeiramente específicos do IPv4: O NLRI na mensagem de UPDATE contém um prefixo IPv4 O atributo NEXT_HOP na mensagem de UIPDATE contém um endereço IPv4 O BGP ID no atributo AGGREGATOR There are only three pieces of information, carried by BGP, that are IPv4 specific: the NEXT_HOP attribute (expressed as an IPv4 address), AGGREGATOR (contains an IPv4 address), and NLRI (expressed as IPv4 address prefixes). So, to provide backward compatibility, as well as to simplify introduction of the multiprotocol capabilities into BGP-4, two new optional attributes were created:, Multiprotocol Reachable NLRI (MP_REACH_NLRI) and Multiprotocol Unreachable NLRI The first one (MP_REACH_NLRI) is used to carry the set of reachable destinations together with the next hop information to be used for forwarding to these destinations. The second one (MP_UNREACH_NLRI) is used to carry the set of unreachable destinations.

BGP Multiprotocolo O RFC 4760 define extensões multi-protocolo para o BGP4 Isto torna o BGP4 disponível para outros protocolos de rede (IPv6, MPLS…) Novos atributos do BGP4: MP_REACH_NLRI MP_UNREACH_NLRI Atributo NEXT_HOP independente de protocolo Atributo NLRI independente de protocolo There are only three pieces of information, carried by BGP, that are IPv4 specific: the NEXT_HOP attribute (expressed as an IPv4 address), AGGREGATOR (contains an IPv4 address), and NLRI (expressed as IPv4 address prefixes). So, to provide backward compatibility, as well as to simplify introduction of the multiprotocol capabilities into BGP-4, two new optional attributes were created:, Multiprotocol Reachable NLRI (MP_REACH_NLRI) and Multiprotocol Unreachable NLRI The first one (MP_REACH_NLRI) is used to carry the set of reachable destinations together with the next hop information to be used for forwarding to these destinations. The second one (MP_UNREACH_NLRI) is used to carry the set of unreachable destinations.

Encaminhamento IPv6 vs. IPv4 a Nível Global (10/03/2008) IPv6 IPv4 ROTAS 1235 255998 ROTAS AGREGADAS 1114 (90,2%) 165340 (64,6%) SISTEMAS AUTÓNOMOS 918 27796 O IPv6 ainda está a anos luz do IPv4 pelo que se pode ver por estas estatísticas. No entanto, algo facilmente visível é que o nível de agregação por sistema autónomo é Infinitamente melhor em IPv6. www.cidr-report.org

Conclusões Protocolo IPv4 IPv6 Processos RIP RIPv1/RIPv2 RIPng Dois OSPF OSPFv2 OSPFv3 IS-IS Um BGP BGP4 BGP4+

Conclusões Os principais protocolos de encaminhamento já têm suporte IPv6 estável Não existem diferenças significativas entre o funcionamento do encaminhamento entre o IPv4 e o IPv6 Muitas redes apenas existem no mundo IPv4

Questões ? Obrigado !