Concept Guide

Discard Counters........................................................................................................................................................... 454
Display discard counters......................................................................................................................................... 454
22 Internet Protocol Security (IPSec).......................................................................................................... 456
Conguring IPSec .........................................................................................................................................................456
23 IPv4 Routing............................................................................................................................................458
IP Addresses...................................................................................................................................................................459
Implementation Information....................................................................................................................................459
Conguration Tasks for IP Addresses......................................................................................................................... 459
Assigning IP Addresses to an Interface.......................................................................................................................459
Conguring Static Routes............................................................................................................................................ 460
Congure Static Routes for the Management Interface...........................................................................................461
IPv4 Path MTU Discovery Overview.......................................................................................................................... 462
Packet handling during MTU mismatch................................................................................................................462
Using the Congured Source IP Address in ICMP Messages..................................................................................462
Conguring the ICMP Source Interface............................................................................................................... 462
Conguring the Duration to Establish a TCP Connection........................................................................................ 463
Enabling Directed Broadcast........................................................................................................................................ 463
Resolution of Host Names............................................................................................................................................464
Enabling Dynamic Resolution of Host Names............................................................................................................464
Specifying the Local System Domain and a List of Domains................................................................................... 464
Conguring DNS with Traceroute............................................................................................................................... 465
ARP................................................................................................................................................................................. 466
Conguration Tasks for ARP........................................................................................................................................ 466
Conguring Static ARP Entries....................................................................................................................................466
Enabling Proxy ARP.......................................................................................................................................................467
Clearing ARP Cache...................................................................................................................................................... 467
ARP Learning via Gratuitous ARP................................................................................................................................467
Enabling ARP Learning via Gratuitous ARP................................................................................................................467
ARP Learning via ARP Request................................................................................................................................... 468
Conguring ARP Retries...............................................................................................................................................468
ICMP............................................................................................................................................................................... 469
Conguration Tasks for ICMP......................................................................................................................................469
Enabling ICMP Unreachable Messages...................................................................................................................... 469
ICMP Redirects..............................................................................................................................................................469
UDP Helper......................................................................................................................................................................471
Congure UDP Helper............................................................................................................................................. 471
Important Points to Remember.............................................................................................................................. 471
Enabling UDP Helper......................................................................................................................................................471
Conguring a Broadcast Address................................................................................................................................. 471
Congurations Using UDP Helper................................................................................................................................472
UDP Helper with Broadcast-All Addresses.................................................................................................................472
UDP Helper with Subnet Broadcast Addresses.........................................................................................................473
UDP Helper with Congured Broadcast Addresses.................................................................................................. 473
UDP Helper with No Congured Broadcast Addresses............................................................................................ 474
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