Baixado 14 vezes
Sumarizacao agregacao de_rotas
- 1. Protocolos de encaminhamento Conceitos - Agregaçãode rotas - Sumarização
- 2. VLSM - Variable-LengthSubnet Mask O que é VLSM e porquê que é usado? Redes de Computadores 1
- 3. Desperdício de espaço Já se pode usar a 1ª subnet e a última!! Nos IOS Cisco estão activas por default. Desactiva “no ip subnet-zero” Redes de Computadores 1
- 4. Onde usar VLSM? Redesde Computadores 1
- 5. Cálculo de subredesVLSM Redes de Computadores 1
- 6. Exemplo VLSM Redes deComputadores 1
- 7. Agregação de Rotas A agregação de rotas é importante porque: Redes perto umas das outras poupam espaço na tabela de encaminhamento Cada rede necessita de uma entrada na tabela de encaminhamento Cada subrede necessita de uma entrada na tabela de encaminhamento A agregação pode reduzir o tamanho da tabela de encaminhamento Redes de Computadores 1
- 8. Route Summarization Sumarização de rotas • Without route summarization, Internet backbone routing would likely have collapsed sometime before 1997 !! Redes de Computadores 1
- 9. Exemplo 1 -Sumarização Redes de Computadores 1
- 10. Exemplo 2 -Sumarização Redes de Computadores 1
- 11. Configurando VLSM Redes deComputadores 1
Notas do Editor
- #4 In the past, the first and last subnet were not supposed to be used. The use of the first subnet, which was known as subnet zero, was discouraged because of the confusion that could occur if a network and a subnet had the same address. This also applied to the use of the last subnet , which was known as the all-ones subnet. With the evolution of network technologies and IP address depletion, the use of the first and last subnets have become an acceptable practice in conjunction with VLSM. (ver fig) If the team decides to use subnet zero, there will be 8 useable subnets. Each subnet can support 30 hosts. If the team decides to use the no ip subnet-zero command, there will be 7 usable subnets with 30 hosts in each subnet. Cisco routers with Cisco IOS version 12.0 or later, use subnet zero by default.
- #9 Without route summarization, Internet backbone routing would likely have collapsed sometime before 1997 For summarization to work, addresses should be carefully assigned in a hierarchical fashion so that summarized addresses will share the same high-order bits.
- #12 The following are VLSM calculations for the LAN connections in Figure : Network address: 192.168.10.0 The Perth router has to support 60 hosts. That means a minimum of six bits are needed in the host portion of the address. Six bits will yield 2^6 – 2, or 62 possible host addresses. The LAN connection for the Perth router is assigned the 192.168.10.0/26 subnet. The Sydney and Singapore routers have to support 12 hosts each. That means a minimum of four bits are needed in the host portion of the address. Four bits will yield 2^4 – 2, or 14 possible host addresses. The LAN connection for the Sydney router is assigned the 192.168.10.96/28 subnet and the LAN connection for the Singapore router is assigned the 192.168.10.112/28 subnet. The KL router has to support 28 hosts. That means a minimum of five bits are needed in the host portion of the address. Five bits will yield 25 – 2, or 30 possible host addresses. The LAN connection for the KL router is assigned the 192.168.10.64/27 subnet.