Administrator Guide

23 Internet Protocol Security (IPSec)............................................................................ 378
Conguring IPSec ..........................................................................................................................................................378
24 IPv4 Routing............................................................................................................. 380
IP Addresses.................................................................................................................................................................. 380
Implementation Information......................................................................................................................................380
Conguration Tasks for IP Addresses....................................................................................................................... 380
IPv4 Path MTU Discovery Overview..............................................................................................................................383
Using the Congured Source IP Address in ICMP Messages......................................................................................... 384
Conguring the ICMP Source Interface................................................................................................................... 384
Conguring the Duration to Establish a TCP Connection............................................................................................... 384
Enabling Directed Broadcast.......................................................................................................................................... 385
Resolution of Host Names............................................................................................................................................. 385
Enabling Dynamic Resolution of Host Names...........................................................................................................385
Specifying the Local System Domain and a List of Domains.....................................................................................386
Conguring DNS with Traceroute.............................................................................................................................386
ARP................................................................................................................................................................................387
Conguration Tasks for ARP.....................................................................................................................................387
ARP Learning via Gratuitous ARP...................................................................................................................................388
ARP Learning via ARP Request......................................................................................................................................389
Conguring ARP Retries................................................................................................................................................ 389
ICMP............................................................................................................................................................................. 390
Conguration Tasks for ICMP.................................................................................................................................. 390
UDP Helper....................................................................................................................................................................390
Congure UDP Helper..............................................................................................................................................390
Important Points to Remember.................................................................................................................................391
Enabling UDP Helper.................................................................................................................................................391
Congurations Using UDP Helper................................................................................................................................... 391
UDP Helper with Broadcast-All Addresses................................................................................................................391
UDP Helper with Subnet Broadcast Addresses........................................................................................................ 392
UDP Helper with Congured Broadcast Addresses..................................................................................................393
UDP Helper with No Congured Broadcast Addresses............................................................................................ 393
Troubleshooting UDP Helper.......................................................................................................................................... 393
25 IPv6 Addressing........................................................................................................ 395
Protocol Overview......................................................................................................................................................... 395
Extended Address Space......................................................................................................................................... 395
Stateless Autoconguration..................................................................................................................................... 395
IPv6 Header Fields.........................................................................................................................................................396
Version (4 bits)......................................................................................................................................................... 397
Trac Class (8 bits)..................................................................................................................................................397
Flow Label (20 bits)..................................................................................................................................................397
Payload Length (16 bits)...........................................................................................................................................397
Next Header (8 bits)................................................................................................................................................ 397
Hop Limit (8 bits).....................................................................................................................................................398
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