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Routing Protocols & Troubleshooting the Network Semester 2, Chapter 12-13. Static Routing. Static Routes – configure with ip route command, example: (config)#ip route network address SNMask interface address Administrative distance is the rating of trustworthiness of routing info source
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Routing Protocols & Troubleshooting the Network Semester 2, Chapter 12-13
Static Routing • Static Routes – configure with ip route command, example: • (config)#ip route network address SNMask interface address • Administrative distance is the rating of trustworthiness of routing info source • Can go from 0 to 255 • Static routes are 1 • Default for RIP is 120
Default Routes • Use default route when you only have partial information about destination network • Send data to default network when you don’t have info in routing table • Keeps routing table shorter • IP Default-network command addes to all routers in network, example: • IP default-network 152.43.0.0
Autonomous Systems • A group of routers that show a consistent view of routing to the outside world. • Assigned a unique number by InterNIC • IGRP routing protocol requires an assigned number Ex: Router IGRP 100 • Exterior routing protocols are used between autonomous systems -BGP
RIP • Distance Vector Protocol • Uses hop count – over 15 is discarded • Sends updates every 30 seconds • (Config)#router rip • (config-router)#network <attached network(s)> • Show ip protocol command shows protocol, networks, gateways, distance, update times, administrative distance • Show ip route – contents of routing table
Troubleshooting The Network: • Examples of problems in each layer might include: • Layer 1 - incorrect cable used • Layer 2 - interface not configured for Ethernet • Layer 3 - subnet mask is incorrect
Layer 1 errors include: • broken cables • disconnected cables • cables connected to the wrong ports • intermittent cable connection • wrong cables used for the task at hand (must use rollovers, cross-connects, and straight-through cables correctly) • transceiver problems • DCE cable problems • DTE cable problems • devices turned off
Layer 2 errors include: • improperly configured serial interfaces • improperly configured Ethernet interfaces • improper encapsulation set (HDLC is default for serial interfaces) • improper clockrate settings on serial interfaces
Layer 3 errors include: • routing protocol not enabled • wrong routing protocol enabled • incorrect IP addresses • incorrect Subnet Masks • incorrect DNS to IP bindings