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Network Layer Protocol.pptx

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SeekayAlaisKaruppaia

This document summarizes several network layer protocols and concepts: - It describes protocols like IPv4, IPv6, DHCP, ICMP, Mobile IP, NAT, routing, multicast routing, AS, DVR, RIP, LSR, OSPF, DVMRP, PIM, BGP and their functions and characteristics. - It also explains related concepts such as unicast and multicast routing, autonomous systems, and BGP autonomous system relationships.

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Network Layer Protocol
IPv4
IPv6
Network Layer Protocol.pptx
DHCP
Network Layer Protocol.pptx
ICMP • The Internet Control Message Protocol (ICMP) is used by routers and hosts to send network control information to each other. • In practice, ICMP is an integral part of IP and all IP modules must support the ICMP protocol
Network Layer Protocol.pptx
Network Layer Protocol.pptx
MOBILE IP
NAT
Network Layer Protocol.pptx
Routing • Routing is the process of selecting a path for traffic in a network or between or across multiple networks. • Unicast Routing – Distance Vector Routing – Link State Routing – BGP • Multicast Routing – DVMRP – MULTICAST OSPF – PIM
Network Layer Protocol.pptx
Network Layer Protocol.pptx
Network Layer Protocol.pptx
AS
DVR
RIP
• Command (8 bits): This field indicates the packet type. Value 1 represents a request packet. Value 2 represents a response packet. • Version (8 bits): It indicates the RIP version number. For RIPv2, the value is 0x 02. • Family of net 1 (16 bits): When the value is 2, it represents the IP protocol of the network. • Route tag (16 bits): It indicates the external route tag and contains the AS number of external network. • Subnet mast (32 bits): It indicates the mask of the destination address for administrative purposes. • Distance to net 1 (32 bits): It provides a better next hop address that announces next hop router. If it is 0.0.0.0, it indicates the address of the advertising router is the optimal next hop address.
Advantages • RIP for IP is easy to implement. In its simplest default configuration • RIP for IP is as easy as configuring IP address and subnet masks for each router interface and then turning on the router. • RIP for IP has a large installed base consisting of small and medium sized IP internetworks that do not wish to bear the design and configuration burden of the OSPF. Drawbacks • Two shortcomings associated with the RIP protocol are slow convergence and instability. • Procedures to remedy RIP instability include triggered update, spilt horizons and poison reverse.
LSR 1. Initialize the Confirmed list with an entry for myself; this entry has a cost of 0. 2. For the node just added to the Confirmed list in the previous step, call it node Next, select its LSP. 3. For each neighbor (Neighbor) of Next, calculate the cost (Cost) to reach this Neighboras the sum of the cost from myself to Next and from Next to Neighbor. (a) If Neighbor is currently on neither the Confirmed nor the Tentative list, then add (Neighbor, Cost, NextHop) to the Tentative list, where NextHop is the direction I go to reach Next. (b) If Neighbor is currently on the Tentative list, and the Cost is less than the currently listed cost for Neighbor, then replace the current entry with (Neighbor, Cost, NextHop), where NextHop is the direction I go to reach Next. 4. If the Tentative list is empty, stop. Otherwise, pick the entry from the Tentative list with the lowest cost, move it to the Confirmed list, and return to step 2.
Network Layer Protocol.pptx
Advantages:- 1) It is used in finding Shortest Path. 2) It is used in geographical Maps 3) To find locations of Map which refers to vertices of graph. 4) Distance between the location refers to edges. 5) It is used in IP routing to find Open shortest Path First. 6) It is used in the telephone network. Disadvantages:- 1) It do blind search so wastes lot of time while processing. 2) It cannot handle negative edges. 3) This leads to acyclic graphs and most often cannot obtain the right shortest path.
OSPF The Version field: currently set to 2, and the Type field may take the values 1 through 5. Type: Are the ―hello message, request, send, ack and LSA. The AreaId: is a 32-bit identifier of the area. Checksum: 16-bit checksum to protected data. The Authentication type : is 0 if no authentication is used; otherwise it may be 1, implying a simple password is used, or 2, which indicates that a cryptographic authentication. LS age : TTL value. Type : Type 1 LSA. Link state ID: Advertising Router Fields Are Identical. Advertising router : 32 Bit Identifier for the Router That Created LSA. LS sequence number : To Detect Old or Duplicate LSAs. LS checksum : Verify Data That Is Corrupted during Transmission. Length : Length of LSA. TOS : Type of Service. Link ID : link data: To Identify Link. Link type : Used to Identify the Type of Link. Metric : Cost of the Link.
Multicast Routing Multicast is a special form of broadcast in which a single source transmits the packets and they are delivered to specified subgroup of network hosts (one-to-many). Multicast Address • A multicast address is assigned to a set of interfaces that typically belong to different nodes. • A packet that is sent to multicast address is delivered to all interfaces that have joined the corresponding multicast group. • Multicast addresses are formed according to several specific formatting rules, depending on the application. Multicast Routing • In case of unicast routing, forwarding tables stores IP address of destination. Forwarding table specify a set of paths. • In multiple routing, forwarding table stores multicast address. Router duplicates the packet if it is to be forwarded over multiple links. Forwarding table specify a set of trees. bits 8 4 4 112 field prefi x flags sc Group ID
DVMRP • Distance Vector Multicast Routing Protocol. • DVMRP is used the source-based least cost trees, but the router never actually makes a routing table. • Flooding – Broadcasts packets, but creates loops in the system • Reverse Path Forwarding (RPF) – RPF eliminates the loop in the flooding process. • Reverse Path Broadcasting (RPB) – RPB eliminates duplication. • Reverse Path Multicasting (RPM) – To increase efficiency, the multicast packet must reach only those networks that have active members for that particular group. This is called reverse path multicasting (RPM). – Pruning – Grafting
Network Layer Protocol.pptx
PIM • Protocol Independent Multicast – Dense Mode (PIM-DM) – Sparse Mode (PIM-SM) • PIM operation: (a) R4 sends Join to RP and joins shared tree. (b) R5 joins shared tree. (c) RP builds source-specific tree to R1 by sending Join to R1. (d) R4 and R5 build source- specific tree to R1 by sending Joins to R1.
PIM-DM • PIM-DM is used in a dense multicast environment, such as a LAN. • PIM-DM uses RPF and pruning and grafting strategies to handle multicasting. However, it is independent of the underlying unicast protocol. • PIM-DM is a source-based tree routing protocol that uses RPF and pruning and grafting strategies for multicasting. Its operation is like that of DVMRP; however, unlike DVMRP, it does not depend on a specific unicasting protocol. • This unicast protocol can be a distance vector protocol (RIP) or link state protocol (OSPF).
BGP – Obtain subnet reachability from neighboring ASs. – Propagate the reachability information to all routers internal to the AS. – Determine “good” routers to subnets based on the reachability information and on AS policy.
Network Layer Protocol.pptx
AS Relationship – Provider-customer: provider connect customer to the internet. Customer may be a corporation or ISP. Policy is to advertise all routes to customer, and advertise routes learn from customer to everyone. – Customer-provider: customer sends traffic to internet through provider. Policy is to advertise routes between customer and provider. But don’t advertise routes learned from one provider to another provider – Peer: two providers who view themselves as equal usually peer so they can get access to other’s customer without having to pay another provide.

More Related Content

Network Layer Protocol.pptx

  • 7. ICMP • The Internet Control Message Protocol (ICMP) is used by routers and hosts to send network control information to each other. • In practice, ICMP is an integral part of IP and all IP modules must support the ICMP protocol
  • 11. NAT
  • 13. Routing • Routing is the process of selecting a path for traffic in a network or between or across multiple networks. • Unicast Routing – Distance Vector Routing – Link State Routing – BGP • Multicast Routing – DVMRP – MULTICAST OSPF – PIM
  • 17. AS
  • 18. DVR
  • 19. RIP
  • 20. • Command (8 bits): This field indicates the packet type. Value 1 represents a request packet. Value 2 represents a response packet. • Version (8 bits): It indicates the RIP version number. For RIPv2, the value is 0x 02. • Family of net 1 (16 bits): When the value is 2, it represents the IP protocol of the network. • Route tag (16 bits): It indicates the external route tag and contains the AS number of external network. • Subnet mast (32 bits): It indicates the mask of the destination address for administrative purposes. • Distance to net 1 (32 bits): It provides a better next hop address that announces next hop router. If it is 0.0.0.0, it indicates the address of the advertising router is the optimal next hop address.
  • 21. Advantages • RIP for IP is easy to implement. In its simplest default configuration • RIP for IP is as easy as configuring IP address and subnet masks for each router interface and then turning on the router. • RIP for IP has a large installed base consisting of small and medium sized IP internetworks that do not wish to bear the design and configuration burden of the OSPF. Drawbacks • Two shortcomings associated with the RIP protocol are slow convergence and instability. • Procedures to remedy RIP instability include triggered update, spilt horizons and poison reverse.
  • 22. LSR 1. Initialize the Confirmed list with an entry for myself; this entry has a cost of 0. 2. For the node just added to the Confirmed list in the previous step, call it node Next, select its LSP. 3. For each neighbor (Neighbor) of Next, calculate the cost (Cost) to reach this Neighboras the sum of the cost from myself to Next and from Next to Neighbor. (a) If Neighbor is currently on neither the Confirmed nor the Tentative list, then add (Neighbor, Cost, NextHop) to the Tentative list, where NextHop is the direction I go to reach Next. (b) If Neighbor is currently on the Tentative list, and the Cost is less than the currently listed cost for Neighbor, then replace the current entry with (Neighbor, Cost, NextHop), where NextHop is the direction I go to reach Next. 4. If the Tentative list is empty, stop. Otherwise, pick the entry from the Tentative list with the lowest cost, move it to the Confirmed list, and return to step 2.
  • 24. Advantages:- 1) It is used in finding Shortest Path. 2) It is used in geographical Maps 3) To find locations of Map which refers to vertices of graph. 4) Distance between the location refers to edges. 5) It is used in IP routing to find Open shortest Path First. 6) It is used in the telephone network. Disadvantages:- 1) It do blind search so wastes lot of time while processing. 2) It cannot handle negative edges. 3) This leads to acyclic graphs and most often cannot obtain the right shortest path.
  • 25. OSPF The Version field: currently set to 2, and the Type field may take the values 1 through 5. Type: Are the ―hello message, request, send, ack and LSA. The AreaId: is a 32-bit identifier of the area. Checksum: 16-bit checksum to protected data. The Authentication type : is 0 if no authentication is used; otherwise it may be 1, implying a simple password is used, or 2, which indicates that a cryptographic authentication. LS age : TTL value. Type : Type 1 LSA. Link state ID: Advertising Router Fields Are Identical. Advertising router : 32 Bit Identifier for the Router That Created LSA. LS sequence number : To Detect Old or Duplicate LSAs. LS checksum : Verify Data That Is Corrupted during Transmission. Length : Length of LSA. TOS : Type of Service. Link ID : link data: To Identify Link. Link type : Used to Identify the Type of Link. Metric : Cost of the Link.
  • 26. Multicast Routing Multicast is a special form of broadcast in which a single source transmits the packets and they are delivered to specified subgroup of network hosts (one-to-many). Multicast Address • A multicast address is assigned to a set of interfaces that typically belong to different nodes. • A packet that is sent to multicast address is delivered to all interfaces that have joined the corresponding multicast group. • Multicast addresses are formed according to several specific formatting rules, depending on the application. Multicast Routing • In case of unicast routing, forwarding tables stores IP address of destination. Forwarding table specify a set of paths. • In multiple routing, forwarding table stores multicast address. Router duplicates the packet if it is to be forwarded over multiple links. Forwarding table specify a set of trees. bits 8 4 4 112 field prefi x flags sc Group ID
  • 27. DVMRP • Distance Vector Multicast Routing Protocol. • DVMRP is used the source-based least cost trees, but the router never actually makes a routing table. • Flooding – Broadcasts packets, but creates loops in the system • Reverse Path Forwarding (RPF) – RPF eliminates the loop in the flooding process. • Reverse Path Broadcasting (RPB) – RPB eliminates duplication. • Reverse Path Multicasting (RPM) – To increase efficiency, the multicast packet must reach only those networks that have active members for that particular group. This is called reverse path multicasting (RPM). – Pruning – Grafting
  • 29. PIM • Protocol Independent Multicast – Dense Mode (PIM-DM) – Sparse Mode (PIM-SM) • PIM operation: (a) R4 sends Join to RP and joins shared tree. (b) R5 joins shared tree. (c) RP builds source-specific tree to R1 by sending Join to R1. (d) R4 and R5 build source- specific tree to R1 by sending Joins to R1.
  • 30. PIM-DM • PIM-DM is used in a dense multicast environment, such as a LAN. • PIM-DM uses RPF and pruning and grafting strategies to handle multicasting. However, it is independent of the underlying unicast protocol. • PIM-DM is a source-based tree routing protocol that uses RPF and pruning and grafting strategies for multicasting. Its operation is like that of DVMRP; however, unlike DVMRP, it does not depend on a specific unicasting protocol. • This unicast protocol can be a distance vector protocol (RIP) or link state protocol (OSPF).
  • 31. BGP – Obtain subnet reachability from neighboring ASs. – Propagate the reachability information to all routers internal to the AS. – Determine “good” routers to subnets based on the reachability information and on AS policy.
  • 33. AS Relationship – Provider-customer: provider connect customer to the internet. Customer may be a corporation or ISP. Policy is to advertise all routes to customer, and advertise routes learn from customer to everyone. – Customer-provider: customer sends traffic to internet through provider. Policy is to advertise routes between customer and provider. But don’t advertise routes learned from one provider to another provider – Peer: two providers who view themselves as equal usually peer so they can get access to other’s customer without having to pay another provide.