Criminal Record Management
Chapter 13
Routing Protocols (RIP, OSPF, BGP)
• • • • INTERIOR AND EXTERIOR ROUTING RIP OSPF BGP
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©The McGraw-Hill Companies, Inc., 2000 1 © Adapted for use at JMU by Mohamed Aboutabl, 2003
Introduction
Packets may pass through several networks on their way to destination Each network carries a price tag, or a “metric” The metric of a network may be: constant (i.e. each network costs one hop) Service type-dependent (the cost of the network depends on what service the packet needs: e.g. throughput, delay, .. etc.) Policy-dependent: a policy defines what paths should, or should not, be followed. The router uses a “routing table” to determine the path Static vs. Dynamic routing tables.
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©The McGraw-Hill Companies, Inc., 2000 2 © Adapted for use at JMU by Mohamed Aboutabl, 2003
13.1 Interior & Exterior Routing Autonomous system: a group of networks and routers under authority of a single administrator
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©The McGraw-Hill Companies, Inc., 2000 3 © Adapted for use at JMU by Mohamed Aboutabl, 2003
Popular routing protocols
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©The McGraw-Hill Companies, Inc., 2000 4 © Adapted for use at JMU by Mohamed Aboutabl, 2003
13.2 RIP: Routing Information Protocol
Distance Vector Routing Share the most you know about the entire autonomous system Share with all your direct neighbors, and them only Share periodically, e.g. every 30 seconds
Destination 163.5.0.0 197.5.13.0 189.45.0.0 Hop Count 7 5 4 Next Hop 172.6.23.4 176.3.6.17 200.5.1.6 Other Info
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©The McGraw-Hill Companies, Inc., 2000 5 © Adapted for use at JMU by Mohamed Aboutabl, 2003
RIP Updating Algorithm
Receive: a response RIP message 1. Add one to the hop count for each advertised destination 2. Repeat for each advertised destination If ( destination is not in my routing table) Add the destination to my table Else If ( next-hop field is the same) Replace existing entry with the new advertised one Else if (advertised hop-count –after incrementing- is smaller) Replace existing entry with the new advertised
Routing Protocols (RIP, OSPF, BGP)
• • • • INTERIOR AND EXTERIOR ROUTING RIP OSPF BGP
1
©The McGraw-Hill Companies, Inc., 2000 1 © Adapted for use at JMU by Mohamed Aboutabl, 2003
Introduction
Packets may pass through several networks on their way to destination Each network carries a price tag, or a “metric” The metric of a network may be: constant (i.e. each network costs one hop) Service type-dependent (the cost of the network depends on what service the packet needs: e.g. throughput, delay, .. etc.) Policy-dependent: a policy defines what paths should, or should not, be followed. The router uses a “routing table” to determine the path Static vs. Dynamic routing tables.
2
©The McGraw-Hill Companies, Inc., 2000 2 © Adapted for use at JMU by Mohamed Aboutabl, 2003
13.1 Interior & Exterior Routing Autonomous system: a group of networks and routers under authority of a single administrator
3
©The McGraw-Hill Companies, Inc., 2000 3 © Adapted for use at JMU by Mohamed Aboutabl, 2003
Popular routing protocols
4
©The McGraw-Hill Companies, Inc., 2000 4 © Adapted for use at JMU by Mohamed Aboutabl, 2003
13.2 RIP: Routing Information Protocol
Distance Vector Routing Share the most you know about the entire autonomous system Share with all your direct neighbors, and them only Share periodically, e.g. every 30 seconds
Destination 163.5.0.0 197.5.13.0 189.45.0.0 Hop Count 7 5 4 Next Hop 172.6.23.4 176.3.6.17 200.5.1.6 Other Info
5
©The McGraw-Hill Companies, Inc., 2000 5 © Adapted for use at JMU by Mohamed Aboutabl, 2003
RIP Updating Algorithm
Receive: a response RIP message 1. Add one to the hop count for each advertised destination 2. Repeat for each advertised destination If ( destination is not in my routing table) Add the destination to my table Else If ( next-hop field is the same) Replace existing entry with the new advertised one Else if (advertised hop-count –after incrementing- is smaller) Replace existing entry with the new advertised