3-way handshaking, 555
90-second timer (IGRP), 254
A class IP addresses, 18–19
address masks, 20
subnetting, 24
ABRs (Area Border Routers), 369, 516
access-class command, 794
access-list compiled command, 789
Aceves, J.J. Garcia Luna, 137
Acknowledgment Number field (TCP), 43
acknowledgments, 364
delayed, 365
direct, 365
ACLs (access control lists)
calling, 792–793
access-class command, 794
categories of, 775
comments, adding, 783–784
dynamic, 786
editing, 780
effect on switching, 800
effect on system performance, 799
effect on system performance, 788
example of, 787–788
features, 786–787
sequence numbers, 786
filter layers, numbering, 778, 780
fragments, handling, 787
ICMP, 791–792
implicit deny any filter, 777
keywords, 796–797
placement of, 799
reflexive, 794
example, 795–796
parameters, 794
sequence number, 781
sequentiality, 778
standard IP, 782–784
Boolean AND/OR functions, 784
inverse masks, 785
TCP, 790
Turbo ACLs, 789
UDP, 791
acquiring hands-on experience, 805
active state, 273
SIA, 274
adding comments to ACLs, 783–784
address aggregation, 293–296
CIDR, 296–297
Address Family Identifier field (RIP), 173
Address Family Identifier field (RIPv2), 202
address masks, 20–21. See also subnet masks
Address Resolution Protocol. See ARP address spaces, designing lollipop-shaped, 152
address summarization
EIGRP, configuring, 315–316
OSPF
configuring, 435–440
troubleshooting, 464–466
addresses, IP, 16
internetworks, 18
masks, 20–21
reverse ARP, 36
RIP, 173
subnet mask, 24
subnets, 24
secondary RIP, 187
adjacencies, 147, 267, 336–337
building process, 358–362
formation of, 351
troubleshooting, 607–610
troubleshooting, 456–458
adjusting RIPng metrics, 233–235
administrative distance, 98, 175
effect on redistribution, 633–639
setting route preferences, 722–723
advertising default networks, 690
aging process (LSAs), 153–154
alternative routes, creating for static routes, 96–97
always keyword (default-information originate command), 694
AND operator, 21
Boolean AND function, 784–785
anycast addresses, 55–56
application layer (TCP/IP), 6
Area ID, 368
Area ID, 368
autonomous systems, 160–162
backbone, 369
IS-IS, 516–517
L1 routers, 517
maximum size of, 369
multiple L1 areas, IS-IS configuration, 604–606
NSSAs, 387–389
configuring, 428–434
partitioned areas, 371
path types, 391
stub areas, 386
configuring, 423–426
totally stubby areas, 387
configuring, 426–428
traffic types, 369
troubleshooting, 460–463
ARP (Address Resolution Protocol), 32–34, 40
gratuitous ARP, 36
packets
Hardware Address Length field, 33
Hardware Type field, 33
Operation field, 33–34
Protocol Address Length field, 33
proxy ARP, 35–36
reverse ARP, 36
arp timeout command, 45
ASBR Summary LSAs, 382
ASBRs (Autonomous System Border Routers), 370
AS-External LSAs, 488–489
assigning metrics to redistributed routes, 644
asynchronous updates, 145–146
ATT (Attached bit), 518
Attempt state (OSPF neighbors), 354
authentication
OSPF, 393
configuring, 441–444
IS-IS, configuring, 587–591
RIPng, 213
RIPv2, 210–212
configuring, 222–224
Authentication Information TLV, 544
auto-cost reference-bandwidth command, 345
automatic summarization, disabling on EIGRP, 307–309
Autonomous System External LSAs, 383, 408–409
autonomous systems, 160–162
B class IP addresses, 18–19
address masks, 20
subnetting, 24
backbone, 369
virtual links, 373–374
backbone routers, 370
IGRP metric, modifying, 257
reference bandwidth, 345
BDRs (Backup Designated Routers), election process, 342–344
best path determination, convergence, 135–137
binary numbering system, 769–770
converting to hex, 772–773
converting to decimal, 771
bitcount format, 24
bits, IP packet flags, 11
Boolean operators
AND, 784–785
OR, 784
boundaries, 174
boundary routers, 177–178
bounded updates, 262
broadcast networks, 339
IPv6 static routes, configuring, 94
broadcast updates, 138
building process for OSPF adjacencies, 358–362
bytes, 770
C class IP addresses, 18–19
address masks, 20
octet boundaries, 26
subnetting, 24–25
calculating
host addresses for subnets, 27–28
hosts per subnet requirements, 25
IGRP default metric, 260–261
place values, 769
calling ACLs, 792–793
access-class command, 794
case studies
IPv6 redistribution with route maps, 759–760
policy routing, 737–740
and QoS, 744–747
and redistribution, 747–751
router configuration, 743
standard IP access lists, 740–742
protocol migration, 711, 714–716
routing loops, 712–714
RIP configuration, 178–180
route filtering, 708–709
filtering by routing process, 710
route tagging, 752–758
categories of ACLs, 775
CCIE exam, preparing for, 803–804
certification path, 805
exam day, 807
hands-on experience, 805
study materials, 805–807
training classes, 804
CDP (Cisco Discovery Protocol), 90, 680–681
enabling, 697
cdp enable command, 698
cdp run command, 698
CEF (Cisco Express Forwarding), 104
per destination load sharing, 103
certification path for CCIE exam, 805
characteristics of distance vector protocols, 138
broadcast updates, 138
full routing table updates, 139
neighbors, 138
Checksum field
LSAs, 366
TCP, 44
CIDR (Classless Interdomain Routing), 296–297
circular sequence number space, 150–151
Cisco IOS Software, switching method determination, 106
classes of IP addresses, 18
classful routing, 23
replies, 170
requests, 170
subnetting, 176
summarization, 177
classless route lookups, 205–206, 682
redistribution into classful domains, 639–640
unmatching masks, 641–642
clear arp-cache command, 34, 45
clear ip accounting command, 801
CLNP (Connectionless Network Protocol), 513
columns in route tables, 82
command field (RIPv2), 202
access class, 794
access-list compiled, 789
arp timeout, 45
auto-cost reference-bandwidth, 345
cdp enable, 698
cdp run, 698
clear ip accounting, 801
config-router, 179
debug arp, 32
debug iegpr neighbors, 321
debug ip icmp, 45
debug ip packet, 123
debug ip policy, 739
debug ipv6 packet, 123
default metric, 644
default-information originate, 691–693
always keyword, 694
for IPv6 addresses, 695–697
distance, 711–712, 715, 719–722
distribute-list, 703, 706, 717–718
eigrp stub, 310
ip access-group, 792–793
ip accounting access-violations, 801
ip cef, 123
ip default network, 687–690
ip default-network, 698
ip load-sharing per packet, 104
ip ospf cost, 389
ip ospf dead-interval, 338
ip ospf priority, 346
ip ospf transmit-delay, 346
ip policy route-map, 743
ip policy-route map, 737
ip rip triggered, 190
ip route, 123
ip route cache, 123
ip router isis, 574
ipv6 cef, 123
ipv6 nd prefix, 71
ipv6 route command, 123
ipv6 unicast-routing, 123
isis isp-interval, 572
lsp-gen-interval, 572
maximum-paths, 393
metric weights, 268
metric-style wide, 560
neighbor, 193
network area, 412–413
no ip proxy-arp, 36
no ip redirects, 40
output-delay, 193–194
redistribute connected, 665
redistribute eigrp, 754
router, 179
router odr, 697–698
set ip next-hop verify-availability, 738
show arp, 34
show cdp, 90
show cdp neighbor detail, 123
show clns is-neighbors, 608
show clns is-neighbors detail, 597
show interface, 256
show ip access list, 800
show ip accounting access-violations, 801
show ip cef, 123
show ip eigrp topology, 268
show ip ospf database, 374
show ip ospf database nssa-external, 409
show ip ospf interface, 344
show ip ospf neighbor, 351–352
show ipv6 cef, 123
show ipv6 detail, 123
show ipv6 interface, 123
show ipv6 rip, 228
show ipv6 route, 123
show isis database, 529
summary address, 652
timers active time, 275
timers basic, 194
trace, 12
variance, 300
which route, 534
comparing
OSPFv2 and OSPFv3, 478–479
RIPng and RIPv2, 213
compatibility of RIPv2 and RIPv1, 205
compatibility switches, 205, 215–217
config-router command, 179
configuring, 187–190
ACLs, keywords, 796–797
default routes, 681–682
in IPv6, 695–697
ip default-network command, 687–690
dual-protocol routing, 711–716
EIGRP, 297–299
address summarization, 315–316
authentication, 316–317
maximum paths for load sharing, 302–304
multiple processes, 305–306
stub routing, 309–315
unequal-cost load balancing, 299–302
extended IP ACLs, 785–789
sequence number, 786
floating static routes, 97–100
ICMP ACLs, 791–792
IPv6 floating static routes, 100–101
IS-IS
authentication, 587–591
IPv4, 574–579
IPv6, 591–595
multiple area addresses, 581–584
multiple L1 areas, 604–606
multiple topology mode, 596–598
route leaking, 598–603
routers, 579–581
load sharing, 102
CEF, 103–104
named ACLs, 797
ODR, 697
OSPF, 411–413
address summarization, 435–440
authentication, 441–444
Domain Name Service lookups, 417–418
LSA filtering, 441
network area command, 412–413
NSSAs, 428–434
on NBMA networks, 446–454
over demand circuits, 454–455
Router IDs, 415–417
secondary addresses, 418–422
stub areas, 423–426
totally stubby areas, 426–428
virtual links, 444–445
OSPFv3, 494–497
multiple instances on a link, 499
on NBMA networks, 500–505
stub area, 497–498
policy routing, 737–740
and QoS, 744–747
and redistribution, 747–751
global router configuration, 743
standard IP access lists, 740–742
redistribution, 642
EIGRP into OSPF, 646–651
IGRP into RIP, 645–646
metrics, 643–644
reflexive ACLs, 794
example, 795–796
parameters, 794
RIP, 178–180
discontiguous subnets, 184–187
metrics, 187–190
passive interfaces, 181–182
unicast updates, 182–184
RIPng, 224–232
global parameters, 232–233
RIPv2, 214
authentication, 222–224
route maps, 734–736
route tagging, 754–758
standard IP ACLs, 782–784
Boolean AND/OR functions, 784
inverse masks, 785
static routes, 84
IPv4, 85–89
IPv6, 90–94
TCP ACLs, 790
UDP ACLs, 791
virtual links, 374
connection-oriented services, TCP, 41–42
control protocols, ICMPv6 header format, 63–64
convergence, 135–137
after router reboot in redistributed protocol environment, 635–637
converting
binary to hex, 772–773
decimal to binary, 771
routing protocols, 711–716
CoS (Class of Service), 9
cost metric, 135, 155, 345, 389
counting to infinity, 142–144
cryptographic checksum, MD5, 211
CSNPs (Complete SNPs), 527, 552
data links
address masks, 21
IP addresses
masks, 20–21
subnets, 24
TCP/IP, 6
data structure of OSPF neighbors, 351
Database Description packets (OSPF), 399–400
data-link identifiers, ARP, 30
DC-bit, 395
DD (Database Description) packets, 358
debug arp command, 32
debug eigrp neighbors command, 321
debug ip icmp command, 45
debug ip packet command, 123
debug ip policy command, 739
debug ip rip command, 180, 193
debug ipv6 packet command, 123
debugging route table entries, 96
decimal numbering system, 769
converting to binary, 771
converting to hexadecimal, 772–773
IP addresses, 17
decision points for OSPF adjacency formation, 357
decision process (IS-IS), 531–534
default metrics, IGRP
calculating, 260–261
modifying, 257
default networks, 253
advertising, 690
classless route lookups, 682
configuring, 681–682
IPv4, 695–697
in IPv6, 695
ip default-network command, 687–690
filtering, 706
flapping, 694
gateway of last resort, 683
in hub-and-spoke topologies, 678
large-scale use of, 678
redistribution, 693
risk of suboptimal routing, 679
static, 682
“don’t care” bits, 683
redistribution, 684–686
default IGRP timers, modifying, 255
default-information originate command, 691–693
always keyword, 694
for IPv6 addresses, 695–697
default-metric command, 644
modifying, 257
delayed acknowledgments, 365
demand circuits, 393
OSPF, configuring, 454–455
presumption of reachability, 394
depletion of IPv4 addresses, 49
designated routers (IS-IS), 523–526
designing
lollipop-shaped address spaces, 152
subnets, 24–25
Destination Address field (IPv6 packets), 60
destination ports, TCP, 43
devices, boundary routers, 177–178
DF bit, 10
DiffServ (Differentiated Services framework), 9
diffusing computations, 262
feasible successor selection process, 273–287
digits, 769
Dijkstra, E.W., 266
Dijkstra’s algorithm, 156–159
direct acknowledgments, 366
directly connected subnets, 176
disabling
automatic summarization on EIGRP, 307–309
split horizon, 722
summarization on RIPv2, 221
discontiguous subnets, 85, 178
configuring, 184–187
RI, 185
summarizing RIPv2 routes across, 220–222
displaying
IGRP delay, 256
IPv6 addresses, 90
IS-IS link state database, 529–530
IS-IS neighbor table, 523
RIPng processes, 228
distance command, 711–712, 715, 719–722
distance vector routing protocols, 137, 261
asynchronous updates, 145–146
characteristics of, 138
broadcast updates, 138
full routing table updates, 139
neighbors, 138
periodic updates, 138
counting to infinity, 143–144
holddown timers, 144–145
RIP
configuring, 178–180
metrics, configuring, 187–190
route filtering, 702
route invalidation timers, 140–141
routing by rumor, 139–140
split horizon, 141
triggered updates, 144
distributed database protocols. See link-state protocols
distribute-list command, 703, 706, 717–718
domain authentication, IS-IS configuration, 590–591
Domain Name Service lookups, OSPF configuration, 417–418
domains
OSPF, areas, 368
IS-IS, domain-wide prefix distribution extension, 556–557
Don’t Fragment (DF) bit, 10
Down state (OSPF neighbors), 353
DRs (Designated Routers), 341
DRothers, 344
election process, 342–344
DSCP (Differentiated Services Code Point), 9
DUAL (Diffusing Update Algorithm), 266–267
feasible successors, selection process, 270–287
input events, 273
dual-protocol routing, configuring, 711–716
Duplicate Address Detection, 73–74
dynamic ACLs, 786
Dynamic Hostname Exchange, 562
dynamic routing protocols, RIP. See RIP (Routing Information Protocol)
echo packets, tracing, 112
Echo Request/Reply messages (ICMP), 39–40
ECN (Explicit Congestion Notification), 10
editing
ACLs, 780
route maps, 735
EGPs (Exterior Gateway Protocols), 162
EIGRP (Enhanced Interior Gateway Routing Protocol), 263
address aggregation, 293–296
CIDR, 296–297
address summarization, configuring, 315–316
adjacencies, 267
authentication, configuring, 316–317
automatic summarization, disabling, 307–309
configuring, 297–299
diffusing computations, 262
DUAL, 266–267
feasible successors, selection process, 270–284, 287
input events, 273
load sharing, configuring maximum paths, 302–304
metrics, 270
delay, 268
FC, 267
FD, 267
feasible successors, 267
variance, 300
missing neighbors, troubleshooting, 318–323
multiple processes, configuring, 305–306
neighbor discovery/recovery, 265–266
neighbor table, 266
packets, 264
header format, 288–289
Hello, 265
sequence numbers, 264
TLVs, 289–293
protocol-dependent modules, 264
Q Count, 266
redistribution into OSPF, 656
configuring, 646–651
RTO, 265–266
RTP, 264
SRTT, 265
stub routing, configuring, 309–315
stuck-in-active neighbors, troubleshooting, 323, 325–327
summarization, 654–655
timers, mulicast flow timer, 265
topological table, contents of, 268
troubleshooting, 317
unequal-cost load balancing, configuring, 299–302
updates, 262
eigrp stub command, 310
election process for DRs/BDRs, 342–344
electrical protocols, 6
embedded IPv4 addresses, 58
enabling
CDP, 697
classless route lookups, 206
per packet load sharing, 104
process switching, 105
encapsulation (SNAP), ARP, 34
environments, 24
EPHOS (European Procurement Handbook for Open Systems), 513
equal-cost load balancing, 102, 175
error correction in IP packets, 13
ES (End System), 515
establishing adjacencies
decision points, 357
OSPF, 351
Ethernet, 184
examples
of diffusing computations, 276–284, 287
of extended IP ACLs, 787–788
of reflexive ACLs, 795–796
exams, CCIE
certification path, 805
preparing for, 803–807
training classes, 804
Exchange state (OSPF neighbors), 354
expiration timer, RIP, 171
explicit acknowledgments, 359, 364
ExStart state (OSPF neighbors), 354
effect on system performance, 788
example of, 787–788
features, 786–787
placement of, 799
sequence numbers, 786
extended metrics, 596
Extended Ping utility, 10
extension headers, 61–63
functions performed, 62
extensions to IS-IS
3-way handshaking, 555
domain-wide prefix distribution, 556–557
Dynamic Hostname Exchange, 562
IPv6 routing, 560
mesh groups, 566–571
Multi Topology routing, 562–564
wide metrics, 558
exterior routes, 253
External Attributes LSAs, 383–385
external routes, 532
summarization, 435
external traffic, 369
failed routes, tracing, 109–112
IPv6, 120–122
fast switching, per destination load sharing, 105
FC (feasible condition), 267
FD (feasible distance), 267, 270
feasible successors, 267
diffusing computations, 273–284, 287
selection process, 270–276
features
of extended IP ACLs, 786–787
of OSPF, 335
of TCP ACLs, 790
fields
of IS-IS Hello PDUs, 541
of IS-IS LSPs, 546–547
of RIPng messages, 214
of TCP header, 42–44
filter layers, numbering, 778, 780
filtering
implicit deny any, 777
IPv6 routes, 704–705
prefix lists, 798
sequentiality, 778
first octet rule, 18–20
Flags field (TCP), 43
flapping routes, 694
flash updates. See triggered updates
Fletcher algorithm, 366
floating static routes, 97–100
IPv6, 100–101
flooding, 147
LSAs, 363
acknowledgments, 364–366
checksum, 366
sequence numbers, 148–149, 366
circular sequence number space, 150–151
linear sequence number space, 149–150
lollipop-shaped sequence number space, 152–153
flooding delays (IS-IS), 571–573
Flow Label field (IPv6 packets), 59
Floyd, Sally, 145
flush timer (RIP), 171
format
of IPv6 multicast addresses, 57
of OSPFv3 LSAs, 484
AS-External LSAs, 488–489
Inter-Area Prefix LSAs, 486–487
Inter-Area Router LSAs, 487
Intra-Area Prefix LSAs, 491–493
Link LSAs, 489–491
Network LSAs, 486
Router LSAs, 484–486
of RA messages, 66
of Redirect messages, 69
of RIPng messages, 213–214
of RIPv2 messages, 201–204
formation of OSPF adjacencies, 351
decision points, 357
Fragment Offset field (IP packets), 11
fragmenting IP packets, 10
fragments, processing through ACLs, 787
Frame-Relay mapping, OSPFv3, 506–509
full routing table updates, 139
Full state (OSPF neighbors), 354
functional protocols (TCP/IP), 6
garbage collection (RIP), 171
gateway of last resort, 683
general TLV fields, 289
global parameters for RIPng configuration, 232–233
global unicast addresses, 53
GOSIP (Government Open Systems Interconnection Profile), 513
gratuitous ARP, 36
Group Membership LSAs, 385
group pacing, 377
Hardware Address Length field (ARP packets), 33
Hardware Type field (ARP packets), 33
Header Checksum field (IP packets), 13
Header Length field
IP packets, 8
TCP packets, 43
headers
EIGRP packet format, 288–289
IP packets, 7–8
flags, 10
Fragment Offset field, 11
Header Checksum field, 13
identifiers, 10
Options field, 14–16
options field, 14
size, 8
TOS, 8
total length, 10
TTL field, 12–13
IS-IS PDU fields, 535–536
TCP, 42–43
UDP, 44–45
Hedrick, Charles, 169
Hello packets
EIGRP, 264
hold time, 265
Hello PDUs, 539
Area Addresses TLV, 542–543
Authentication Information TLV, 544
fields, 541
Intermediate System Neighbors TLV, 543
IP Interface Address TLV, 545
Padding TLV, 543
Protocols Supported TLV, 545
HelloInterval, 338
hexadecimal numbering system, 769–772
converting to decimal, 772–773
IP address format, 24
hexadecimal IPv6 representation, 51
hippity bit, 528
holddown
RIP, 172
IGRP, 255
holddown timers, 144–145
hop count metric, 134, 170–173
Hop Limit field (IPv6 packets), 60
host addresses, subnet mask octet boundaries, 26
hosts
IP addresses, 16–17
quantity per subnet requirement, calculating, 25
host-to-host layer (TCP/IP)
TCP, 41–44
UDP, 44–45
Host-to-Host Layer Protocol, 13
“hot potato” routing, 392
hub-and-spoke topologies
ODR, 680
stub routers, 678
Huitema, Christian, 514
ICMP (Internet Control Message Protocol), 37–38
ACLs, 791–792
echo packets, tracing, 112
Echo Request/Reply messages, 39–40
redirect packets, 40
Router Advertisement packets, 40
Router Selection packets, 40
ICMPv6 header format, 63–64
identifying IPv6 address types, 54
IGPs (Interior Gateway Protocols), 161
IGRP (Interior Gateway Routing Protocol), 253
default timers, modifying, 255
delay, 256–257
holddown, 255
load, 259
metrics, 255
modifying, 256–257
process domains, 252
redistribution into RIP, configuring, 645–646
reliability, 258–259
similarities to RIP, 251
timers
90-second, 254
sleeptime, 255
Implicit Acknowledgments, 359
implicit acknowledgments, 364
implicit deny any filter, 777
improving SPF efficiency on IS-IS networks, 573–574
InfTransDelay, 366
Init state (OSPF neighbors), 354
input events, 273
for OSPF interface state machine, 350
for OSPF neighbors, 356–357
inter-area paths, 391
Inter-Area Prefix LSAs, 486–487
Inter-Area Router LSAs, 487
inter-area summarization, 435
inter-area traffic, 369
Inter-Domain Routing Protocol Information TLV, 551
Interface ID, 53
interface state machine (OSPF), 348–349
input events, 350
interfaces, OSPF, 344
data structure, 344–348
input events, 350
states, 348–349
interface-specific summarization, 653
interior routes, 252
Intermediate System Neighbors TLV, 549
internal routers, 369
internal routes, 532
Internet layer (TCP/IP), 6
internetwork IP addresses, 17–18
intra-area paths, 391
Intra-Area Prefix LSAs, 491–493
intra-area traffic, 369
Intradomain Routing Protocol Discriminator, 535
invalid timers
IGRP, 254
RIP, 171
invalid updates, sources of, 210
inverse masks, 784–785
ip access-group command, 792–793
ip accounting access-violations command, 801
IP Address field
RIP, 173
RIPv2, 203
IP addresses, 16–17
bitcount format, 24
dotted decimal format, 24
dotted-decimal format, 17
first octet rule, 18–20
hexadecimal format, 24
internetworks, 17
masks, 20–21
prefix lists, 798
reverse ARP, 36
RIP, 173
subnet masks, troubleshooting, 29
designing, 24–26
summary routes, 94
IP packets, 7
flags, 10
Fragment Offset field, 11
Header Checksum field, 13
header length, 8
identifiers, 10
Options field, 14–16
Protocol field, 13
TOS (Type of Service), 8
total length, 10
TTL (Time to Live) field, 12
versions of, 8
ip cef command, 123
ip classless command, 682, 698
ip default-network command, 687–690, 698
IP External Reachability TLV, 551
U/D bit, 556
IP External Routes TLV, 291–293
IP Interface Address TLV, 545
IP Internal Reachability TLV, 550–551
U/D bit, 556
IP Internal Routes TLV, 290–291
ip load-sharing, 123
ip load-sharing command, 123
ip load-sharing per-packet command, 104
ip netmask-format, 24
ip netmask-format command, 24, 46
ip ospf cost command, 389
ip ospf dead-interval command, 338
ip ospf priority command, 346
ip ospf transmit-delay command, 346
ip policy route-map command, 737, 743
ip redirects command, 46
ip rip triggered command, 190
ip route command, 123
ip route-cache command, 123
ip router isis command, 574
IP-specific TLV fields, 290
IPv4, 8
configuring on IS-IS, 574–579
depletion of, 49
static routes, configuring, 85–89
IPv6, 8
address representation, 50–51
anycast addresses, 55–56
configuring on IS-IS, 591–595
default-information originate command, default
route configuration, 695–697
double colon representation, 51
embedded IPv4 addresses, 58
extension headers, 61–63
failed routes, tracing, 120–122
floating static routes, 100–101
global unicast addresses, 53
identifying address types, 54
local unicast addresses, 55
modifying static entries on replaced routers, 116–120
multicast addresses, 56–57
NDP, 64–65
address autoconfiguration, 71–73
Duplicate Address Detection, 73–74
messages, 65
Neighbor Address Resolution, 74–75
Neighbor Unreachability Detection, 76–77
privacy addresses, 75–76
router discovery, 70–71
need for, 50
packet header format, 58–60
prefixes, 52
redistribution with route tags, 759–760
RIPng, 212
configuring, 224–232
next-hop route entries, 214
route summarization, 235
route filtering, 704–705
routing with IS-IS, 560
static routes, configuring, 90–94
unspecified addresses, 52
ipv6 cef command, 123
ipv6 nd prefix command, 71
IPv6 Prefix field (RIPng messages), 214
ipv6 route command, 123
ipv6 unicast-routing command, 123
IS (intermediate system), 515
IS-IS (intermediate System-to-Intermediate System), 513
adjacencies, 517
troubleshooting, 607–610
areas, 516
authentication, configuring, 587–591
extensions
3-way handshaking, 555
domain-wide prefix distribution, 556–557
Dynamic Hostname Exchange, 562
IPv6 routing, 560
mesh groups, 566–571
Multi Topology routing, 562–564
wide metrics, 558
flooding delay, 571–572
controlling, 572–573
IPv4, configuring, 574–579
IPv6, configuring, 591–595
layered network architecture, 521
subnetwork dependent functions, 521–526
subnetwork independent functions, 526–534
link-state database
displaying, 529–530
LSPs, 546
fields, 546–547
Inter-Domain Routing Protocol Information TLV, 551
Intermediate System Neighbors TLV, 549
IP External Reachability TLV, 551
IP Internal Reachability TLV, 550–551
TLVs, 547–548
multiple area addresses, configuring, 581–584
multiple L1 areas, configuring, 604–606
multiple topology mode, configuring, 596–598
neighbor table, displaying, 523
NETs, 519
format, 519–520
selecting, 520
on NBMA networks, troubleshooting, 615–619
PDUs
format, 534
header fields, 535–536
Hello PDU format, 539
Hello PDUs, 541–545
IS-IS LSPs, 546–551
IS-IS Sequence Number PDU format, 552–553
TLV fields, 536–539
redistribution into RIP/RIPng, 663–669
route leaking, configuring, 598–603
route summarization, configuring, 585–587
router types, configuring, 579–581
similarities with OSPF, 514
SNPs, 527
SPF efficiency, improving, 573–574
System ID, 519
troubleshooting, 606
virtual link support, 518
isis lsp-interval command, 572
IS-IS Sequence Number PDUs, 552
LSP Entries TLV, 553
Jacobson, Van, 145
key chains, configuring for RIPv2 authentication, 223
keywords for ACL configuration, 796–797
L1 LSPs, TLVs, 547
L1 routers, 517
L1/L2 routers, 517
L2 LSPs, TLVs, 548
L2 routers, 517
LAN Hellos, 540
layered network architecture, IS-IS, 521–534
Level 3 Routing, 162
linear sequence number space, 149–150
link costs, 155
Link State Acknowledgment packets (OSPF), 402
link state refresh process, 376
Link State Request packets (OSPF), 400
Link State Update packets (OSPF), 401
link-local unicast addresses, 55
links, OSPF, 344
link-state advertisements, see LSAs link-state database, 147, 154–156, 336, 363, 374
IS-IS
displaying, 529–530
LSA group pacing, 377
link-state routing protocols, 146, 262
areas, 160–162
Dijkstra’s algorithm, 156–157
router adaptation, 157–159
flooding, 147
sequence numbers, 148–153
IS-IS. See IS-IS
LSAs, 146–147
aging process, 153–154
OSPF. See OSPF
neighbor discovery, 147
route filtering, 702
LIRs (Local Internet Registries), 54
load (IGRP), 259
unequal-cost, EIGRP configuration, 299–302
load sharing
CEF, 103–104
configuring, 102
maximum paths, EIGRP configuration, 302–304
per packet
enabling, 104
process switching, 105–106
Loading state (OSPF neighbors), 354
local computations, 273
local unicast addresses, 55
lollipop-shaped sequence number space, 152–153
lookups
classless, 682
recursive, 107–109
LSAs (link-state advertisements), 146–147, 336, 402, 702
acknowledgments, 359
during flooding process, 364–366
aging process, 153–154
ASBR Summary LSAs, 382
Autonomous System External LSAs, 408–409
External Attributes LSAs, 385
filtering, OSPF configuration, 441
checksum, 366
sequence numbers, 148–150, 152–153
Group Membership LSAs, 385
group pacing, 377
header format, 403
Network Summary LSAs, 381–382, 407–408
Opaque LSAs, 385
Options field, 410
OSPFv3, 481–483
format, 484
Inter-Area AS-External LSAs, 488–489
Inter-Area Prefix LSAs, 486–487
Inter-Area Router LSAs, 487
Intra-Area Prefix LSAs, 491–493
Link LSAs, 489–491
Network LSAs, 486
Router LSAs, 484–486
sequence numbers, 367
types of, 377
LSP Entries TLV, 553
lsp-gen-interval command, 572
LSPs
ATT, 518
flooding delays, 571–573
controlling, 572–573
MAC addresses, ARP, 31
MAC-to-EUI64 conversion, 72–73
masks, 176. See also subnet masks
octet boundaries, 25–27
MaxAge timer, link state refresh, 376
maximum-paths command, 393
MD5, 211
mechanical protocols (TCP/IP), 6
medium internetworks, 18
medium networks, 18
mesh groups, 566–571
messages
ICMP, Echo Request/Reply, 39–40
NDP, 65
OSPFv3, 479–480
RIP, 172–175
RIPng, 213–214
RIPv2, 201–204
Metric field
RIP, 173
RIPng, 214
metric weights command, 268
metrics, 84, 133. See also administrative distance
and redistribution, 633
bandwidth, 134–135
delay, 135
EIGRP, 270
delay, 268
FC, 267
FD, 267, 270
feasible successors, 267
variance, 300
hop-count, 134
IGRP, 255
default metric, calculating, 260–261
load, 259
modifying, 256
reliability, 259
redistribution, configuring, 643–644
reliability, 135
RIPng, adjusting, 233–235
triggered updates, 144
metric-style wide command, 560
MF bit (More Fragments), 11
microflows, 59
migrating to new routing protocols, 711–716
minimizing impact of updates on RIP, 190–193
minimumLSPTransmissionInterval, 528
misconfigured OSPF summarization, troubleshooting, 463–466
missing EIGRP neighbors, troubleshooting, 318–323
missing route table entries, 83
modifying
cost metric, 345
IGRP default metrics, 256–257
IGRP default timers, 255
RouterDeadInterval, 338
More Fragments (MF) bit, 11
MOSPF (Multicast OSPF), 385
MT (Multi Topology) routing, 562–564
MTU (Maximum Transmission Unit), 10
IP packets, 10
multiaccess, 446
multicast addresses, 56–57
multicast flow timer, 265
multiple area addresses, configuring on IS-IS, 581–584
multiple EIGRP processes, configuring, 305–306
multiple L1 areas, IS-IS configuration, 604–606
multiple topology mode, IS-IS configuration, 596–598
mutual redistribution, 657, 701
at multiple redistribution points, 716–722
NA (Neighbor Advertisement) messages, 65
format, 68
NAT (Network Address Translation), 49
NBMA networks, 340
IS-IS, troubleshooting, 615–619
OSPF, configuring, 446–454, 500–505
NDP (Neighbor Discovery Protocol), 64–65
address autoconfiguration, MAC-to-EUI64 conversion, 71–73
Duplicate Address Detection, 73–74
messages, 65–66
Neighbor Address Resolution, 74–75
neighbor discovery, 70–71
Neighbor Unreachability Detection, 76–77
privacy addresses, 75–76
Neighbor Address Resolution, 74–75
neighbor command, 193
neighbor state machine (OSPF), 353–357
neighbor table, 337
EIGRP, 266
Neighbor Unreachability Detection, 76–77
neighbors, 138
adjacencies
formation of, 351
troubleshooting, 456–458
discovery/recovery
adjacencies, 147
EIGRP, 265–266
EIGRP, adjacencies, 267
IS-IS, 522–523
OSPF, 350
adjacency building process, 358–362
data structure, 351–353
input events, 356–357
NETs (Network Entity Titles)
format, 519
selecting, 520
network area command, 412–413
Network Summary LSAs, 382, 407–408
Next Header field (IPv6 packets), 60
Next Hop field (RIPv2), 203
next-hop addresses on replaced routers, troubleshooting, 116–120
next-hop route entries (RIPng), 214
NLA (Next-Level Aggregator), 53
no ip proxy-arp command, 36
no ip redirects command, 40
nonperiodic updates, 262
not-so-stubby areas, 387–389
NPDUs (Network Protocol Data Units), 515
NS (Neighbor Solicitation) messages, 65
NS messages, format, 67
NSSAs (not-so-stubby areas), 388–389
configuring, 428–434
null interface, 656
numbering ACL filter layers, 778–780
numbering systems
binary, 769–770
hexadecimal, 769–773
place values, 769
octets, 770–773
binary, 770
boundary subnet masks, 25–27
hexadecimal, 771–772
subnetting, 26
ODR (On-Demand Routing)
CDP, 680–681
configuring, 697
redistribution, 697
offset lists, RIP, 189
OL (Overload) bit, 528
opaque LSAs, 385
operation of OSPFv3, 477
Operation field (ARP packets), 33–34
operators
Boolean AND function, 21, 784–785
Boolean OR function, 784
optical protocols, 6
Options field
IP packets, 14–16
LSAs, 410
TCP, 44
OSPF (Open Shortest Path First). See also OSPFv3
ABRs, 369
address summarization, configuring, 435–440
adjacencies, 336–337
formation of, decision points, 357
troubleshooting, 456–458
areas, 367
Area ID, 368
backbone, 369
maximum size of, 369
not-so-stubby areas, 387–389
partitioned areas, 371
path types, 391
stub areas, 386
totally stubby areas, 387
traffic types, 369
area-wide problems, troubleshooting, 459
ASBRs, 370
authentication, 393
configuring, 441–444
backbone routers, 370
BDRs, 342
election process, 342–344
broadcast networks, 339
configuring, 411–413
on NBMA networks, 446–454
over demand circuits, 454–455
cost metric, modifying, 345
DD packets, 358
Domain Name Service lookups, configuring, 417–418
DRs, 341
election process, 342–344
features of, 335
Hello packets, 338–339
Hello protocol, 338
interface state machine, 348–349
input events, 350
interfaces, data structure, 344–348
internal routers, 369
isolated areas, troubleshooting, 460–463
link state database, 374
LSA group pacing, 377
link state refresh process, 376
links, 344
loopback interfaces, 337
LSAs, 402
ASBR Summary LSAs, 382
Autonomous System External LSAs, 408–409
External Attributes LSAs, 385
filtering, 441
flooding process, 363
Group Membership LSAs, 385
group pacing, 377
header format, 403
Network Summary LSAs, 381–382, 407–408
Opaque LSAs, 385
Options field, 410
sequence numbers, 367
types of, 377
misconfigured summarization, troubleshooting, 463–466
MOSPF, 385
NBMA networks, 340
neighbor table, 337
neighbors, 350
data structure, 351–353
input events, 356–357
state machine, 353–357
NSSAs, 388–389
configuring, 428–434
over demand circuits, 393
oversubscription, 394
packets, 395–396
Database Description packets, 399–400
header format, 396–398
Hello packets, 398–399
Link State Acknowledgment packets, 402
Link State Request packets, 400
Link State Update packets, 401
point-to-multipoint networks, 340
point-to-point networks, 339
PollInterval, 351
presumption of reachability, 394
pseudonodes, 341
redistribution into EIGRP, configuring, 646–651
reference bandwidth, 345
refresh process versus IS-IS Update
process, 526
route table entries, lookups, 393
Router IDs, 337
configuring, 415–417
RouterDeadInterval, 338
routing table entries
destination types, 390–391
path types, 391–392
secondary addresses, configuring, 418–422
similarities with IS-IS, 514
stub areas, configuring, 423–426
stub networks, 340
totally stubby areas, configuring, 426, 428
transit networks, 340
troubleshooting, 455–456
OSPFv3, 477
configuring, 494–497
Frame-Relay mapping, 506–509
LSAs, 481–483
AS-External LSAs, 488–489
format, 484
Inter-Area Prefix LSAs, 486–487
Inter-Area Router LSAs, 487
Intra-Area Prefix LSAs, 491–493
Link LSAs, 489–491
Network LSAs, 486
messages, 479–480
multiple instances on a link, configuring, 499
on NBMA networks, configuring, 500–505
operation, 477
redistribution into RIPng, 657–663
stub areas configuring, 497–498
troubleshooting, 506
versus OSPFv2, 478–479
out keyword, 706
output-delay command, 193–194
oversubscription, 394
packet filtering routers, 800
packets, 34
ARP, 30–34
Hardware Address Length field, 33
Hardware Type field, 33
Operation field, 33–34
Protocol Address Length field, 33
EIGRP
header format, 288–289
Hello, 265
sequence numbers, 264
TLVs, 289–293
fragments, processing through ACLs, 787
Hello (OSPF), 338–339
ICMP, 37–39
Echo Reply, 39
Echo Request, 39
redirect, 40
Router Advertisement, 40
Router Selection, 40
IP, 7
flags, 10
Fragment Offset field, 11
Header Checksum field, 13
header length, 8
identifiers, 10
Options field, 14–16
Protocol field, 13
TOS (Type of Service), 8
total length, 10
TTL field, 12
IPv6, 58
Destination Address field, 60
Flow Label field, 59
Hop Limit field, 60
Next Header field, 60
Payload Length field, 60
Source Address field, 60
Traffic Class field, 59
LSAs, 402
acknowledgment during flooding process, 364–366
ASBR Summary LSAs, 382
AS-External LSAs, 488–489
Autonomous System External LSAs, 408–409
External Attributes LSAs, 385
Group Membership LSAs, 385
header format, 403
Inter-Area Prefix LSAs, 486–487
Inter-Area Router LSAs, 487
Intra-Area Prefix LSAs, 491–493
Link LSAs, 489–491
Network LSAs, 379–381, 406, 486
Network Summary LSAs, 381–382, 407–408
Opaque LSAs, 385
Options field, 410
OSPFv3, 481–484
Router LSAs, 378–379, 403–406, 484–486
sequence numbers, 367
types of, 377
OSPF, 395–396
Database Description, 358
Database Description packets, 399–400
header format, 396–398
Hello packets, 398–399
Link State Acknowledgment packets, 402
Link State Request packets, 400
Link State Update packets, 401
PDUs. See PDUs (Protocol Data Units)
Padding TLV, 543
parameters
of extended IP ACLs, 786–787
of reflexive ACLs, 794
Partial Route Calculation, 573
partial updates, 262
partitioned areas, 371
passive interfaces, configuring, 181–182
passive state, 273
passive-interface command, 182, 194
path types (OSPF), 391–392
Payload Length field (IPv6 packets), 60
P-bit, 388
PDUs (Protocol Data Units), 515
format, 534
header fields, 535–536
Hello PDUs
Area Addresses TLV, 542–543
Authentication Information TLV, 544
fields, 541
format, 539
Intermediate System Neighbors TLV, 543
IP Interface Address TLV, 545
Padding TLV, 543
Protocols Supported TLV, 545
IS-IS LSPs, 546
fields, 546–547
Inter-Domain Routing Protocol
Information TLV, 551
Intermediate System Neighbors TLV, 549
IP External Reachability TLV, 551
IP Internal Reachability TLV, 550–551
TLVs, 547–548
IS-IS Sequence Number PDU format, 552
LSP Entries TLV, 553
TLV fields, 536–539
per destination load sharing, 105, 301
CEF, 103–104
per packet load sharing
enabling, 104
process switching, 105–106
periodic updates, 138
PHB (Per-Hop Behavior), 9
physical layer (TCP/IP), 6
place values of numbering systems, 769
placement of ACLs, 799
point-to-multipoint networks, 340
point-to-point connections, TCP, 41
point-to-point Hellos, 540
point-to-point networks, 339
policy routing, 731
and QoS, 744–747
and redistribution, 747–751
case study, 737–40
match commands, 733
set commands, 734
standard IP access lists, case study, 740–743
PollInterval, 351
port numbers, 42
ports
sockets, 43
TCP, 43
Prefix Length field (RIPng messages), 214
prefix lists, 798
preparing for CCIE exam, 803–804
certification path, 805
exam day, 807
hands-on experience, 805
study materials, 805–807
training classes, 804
presumption of reachability, 394
privacy addresses, 75–76
procedural protocols, 6
process domains, 252
process switching, 105–106
promiscuous ARP, 35–36
Protocol Address Length field (ARP packets), 33
protocol conflicts, troubleshooting, 112, 115–116
Protocol field, 13
protocol migration, case study, 711–716
protocol-dependent modules, 264
Protocols Supported TLV, 545
proxy ARP, 35–36
resolving protocol conflicts, 115
pseudonodes, 341
PSNPs (Partial SNPs), 527–552
Q Count, 266
QoS and policy routing, 744–747
queries, EIGRP, 264
query origin flags, 275
RA (Router Advertisement) messages, 65–66
RARP (Reverse ARP), 36
recursive table lookups, 107–109
Redirect messages, 65
format, 69
redirects (ICMP), 40
redistribute connected command, 665
redistribute eigrp command, 754
redistribution
administrative distances, 633–639
and policy routing, 747–751
and summarization, 652–657
case study, 708–710
classless to classful protocols, 639–640
unmatching masks, 641–642
configuring, 642
conflicting metrics, 633
convergence after router reboot, 635–637
EIGRP into OSPF, 656
configuring, 646–651
IGRP into RIP, configuring, 645–646
IPv6 addresses with route maps, 759–760
IS-IS into RIP/RIPng, 663–669
match commands, 733
metrics, configuring, 643–644
mutual redistribution, 701
at multiple redistribution points, 716–722
of default routes, 693
of default static routes, 684–686
of ODR-discovered routes, 697
of static routes, 669–671
into dynamic routing protocols, 632
of static routes into OSPF, 631
OSPFv3 into RIPng, 657–663
route feedback, 701
route tagging, 752–758
tagged routes, filtering, 757
routing loops, 636–639
set commands, 733
SIN routing, 632
reference bandwidth, 345
reflexive ACLs, 794
example, 795–796
parameters, 794
reliability as IGRP metric, 135, 258–259
reliable multicast, 264
remarks, adding to ACLs, 783–784
replaced routers, troubleshooting next-hop addresses, 116–120
replies
EIGRP, 264
gratuitous ARP, 36
ICMP, 39
RIP, 170
representation of IPv6 addresses, 50
double colon, 51
prefixes, 52
Request messages (RIP), 170, 174–175
requests
ARP, 30
EIGRP, 264
gratuitous ARP, 36
ICMP, 39
RIP, 170
Reserved field, TCP, 43
Response messages, RIP, 170
reverse ARP, 36
reverse routes, 141
RFCs, ICMP-related, 37
RIB (routing information base). See route tables
RIP (Routing Information Protocol), 169, 172. See also RIPng; RIPv1; RIPv2
classful routing, 175–178
subnetting, 176
summarization, 177
configuring, 178–180
discontiguous subnets, 184–187
metrics, 187
equal-cost load balancing, 175
hop counts, 170
messages, 172–173
metrics, configuring, 187–190
offset lists, 189
passive interfaces, configuring, 181–182
redistribution into IGRP, configuring, 645–646
redistribution into IS-IS, 663–669
replies, 170
Request messages, 174–175
requests, 170
silent hosts, 172
similarities to IGRP, 251
timers, 170–172
triggered updates, 172
troubleshooting, 193
updates
minimizing impact of, 190–193
unicast, configuring, 182–184
RIP_JITTER variable, 170
RIPng (Routing Information Protocol next generation), 212
authentication, 213
configuring, 224–232
global parameters, configuring, 232–233
message format, 213–214
metrics, adjusting, 233–235
misconfigured VLSM, troubleshooting, 236–242
next-hop route entries, 214
processes, displaying, 228
redistribution
into IS-IS, 663–669
into OSPFv3, 657–663
route summarization, 235
RIPv1, compatibility with RIPv2, 205
RIPv2, 201
authentication, 210–212
configuring, 222–224
compability switches, 215–217
compatibility with RIPv1, 205
configuring, 214
messages, 202–204
misconfigured VLSM, troubleshooting, 236–242
similarity to RIPng, 213
summarization, 220–222
VLSM, 218–220
RIRs (Regional Internet Registries), 54
route feedback, 701
route filtering, 701
case study, 708–709
filtering by routing process, case study, 710
specific routes, filtering, 703–708
tagged routes, filtering, 757
route flapping, 135
route invalidation timers, 140–141
IS-IS configuration, 598–603
route lookups, classless, 205–206
route maps, 731
editing, 735
redistribution of IPv6 addresses, 759–760
sequence number, configuring, 734–735
route redistribution. See redistribution
route summarization. See summarization
route tables, 81
administrative distance, 98
columns, 82
entries
debugging, 96
of static routes, 89
floating static routes, IPv6, 100–101
metrics, 84
missing entries, 83
static routes
configuring, 84–94
creating alternative routes, 96–97
floating static routes, 97–100
load sharing, configuring, 102–104
recursive table lookups, 107–109
summarizing, 95
troubleshooting, 109–112
Route Tag field (RIPng messages), 214
Route Tag field (RIPv2), 202
Router Advertisement packets (ICMP), 40
router command, 179
Router IDs, 337
configuring, 415–417
Router LSAs, 378, 403–406, 484–486
router odr command, 697–698
router preferences, setting with administrative distance, 722–723
Router Selection packets (ICMP), 40
RouterDeadInterval, 338
routers
boundary routers, 177–178
configuring on IS-IS, 579–581
IS-IS
designated routers, 523–524, 526
hold time, 522
System ID, 519
“routing by rumor,” 137–140
routing domains versus process domains, 252
Routing Information Protocol. See RIP
routing loops
counting to infinity, 143–144
in redistributed protocol environments, 636–639
troubleshooting, 114
routing policies, 701
routing protocols
classless, 206
redistribution into classful domains, 639–642
distance vector, 137
asynchronous updates, 145–146
characteristics of, 138–139
counting to infinity, 143–144
holddown timers, 144–145
route invalidation timers, 140–141
routing by rumor, 139–140
split horizon, 141
triggered updates, 144
link state, 146
areas, 160
autonomous systems, 160–162
Dijkstra’s algorithm, 156–159
flooding, 147–153
LSAs, 146–147
neighbor discovery, 147
metrics, 133
bandwidth, 134–135
cost, 135
delay, 135
hop count, 134
reliability, 135
selecting, 162–164
routing table entries (OSPF)
destination types, 390–391
lookups, 393
path types, 391–392
RS (Router Solicitation) messages, 65–67
RTO (retransmission timeout), 265–266
RTP (Reliable Transport Protocol), 264
Scholten, C.S., 266
secondary addresses
OSPF configuration, 418–422
RIP, 187
security, authentication
configuring on EIGRP, 316–317
configuring on IS-IS, 587–591
OSPF configuration, 393, 441–444
selecting
NETs, 520
routing protocols, 162–164
Sequence Number field (TCP), 43
sequence numbers, 148–149, 366–367, 734–735, 781, 786
circular sequence number space, 150
EIGRP, 264
linear sequence number space, 149–150
lollipop-shaped sequence number space, 152–153
TCP, 43
sequentiality of access list filters, importance of, 778
set ip next-hop verify-availability command, 738
shortest path first protocols. See link-state routing protocols
show arp command, 34
show cdp command, 90
show cdp neighbor detail command, 123
show clns is-neighbors command, 608
show clns is-neighbors detail command, 597
show interface command, 256
show ip access-list command, 800
show ip accounting access-violations command, 801
show ip cef command, 123
show ip eigrp topology command, 268
show ip osfp interface command, 344
show ip ospf database command, 374
show ip ospf database nssa-external command, 409
show ip ospf neighbor command, 351–352
show ip route command, 83, 123
show ipv6 cef command, 123
show ipv6 cef detail command, 123
show ipv6 interface command, 123
show ipv6 rip command, 228
show ipv6 route command, 123
show isis database command, 529
SIA (stuck-in-active), 274
troubleshooting, 324–327
silent hosts, 172
Simple Internet Protocol (SIP), 8
SIN (ships in the night) routing, 632
SIP (Simple Internet Protocol), 8
site-local unicast addresses, 55
sizing IP packet headers, 8
sleeptime, IGRP, 255
small internetworks, 18
SNAP (subnetwork access protocol), 681
ARP encapsulation, 34
SNPA (Subnetwork Point of Attachment), 515
sockets, 43
solicited-node multicast addresses, 73
Source Address field (IPv6 packets), 60
source ports, TCP, 43
sources of invalid updates, 210
SPF efficiency, improving on IS-IS networks, 573–574
split horizon, 141
disabling, 722
resolving routing loops in redistributed
environments, 637–639
with poisoned reverse, 142, 172
spoofing attacks, 799
SRTT (smooth round-trip time), 265
standard IP ACLs, 782–784
Boolean AND/OR functions, 784
inverse masks, 785
placement of, 799
policy routing configuration, 740–742
static default routes, 682
“don’t care” bits, 683
static routes
administrative distance, 98
configuring, 84
failed routes, tracing, 109–112
floating static routes, creating, 97–100
IPv4, configuring, 85–89
IPv6
configuring, 90–94
floating static routes, 100–101
troubleshooting on replaced routers, 116–120
load sharing
CEF, 103–104
configuring, 102
per destination, 103
per packet, 105–106
policy routes, 731
policy routing
match commands, 733
set commands, 734
protocol conflicts, resolving, 112, 115–116
recursive table lookups, 107–109
redistribution, 669–671
redistribution into dynamic routing protocols, 632
redistribution into OSPF, 631
summarizing, 95
troubleshooting, 109
static routing
creating alternative routes, 96–97
per destination load sharing, 105
configuring, 423–426
stub networks, 340
stub routers, 678
configuring on EIGRP, 309–315
ODR, 680
unreachable destinations, 678
stuck-in-active EIGRP neighbors, troubleshooting, 323–327
study materials for CCIE exam, 805–807
subinterfaces, 208
subnet, 177
subnet hiding, 177
Subnet ID field, 53
Subnet Mask field (RIPv2), 203
subnet masks, 22–24
octect boundaries, 25–27
troubleshooting, 29
unmatching, advertising, 641–642
VLSM, 206–209
bitcount format, 24
classful routing protocols, 23
designing, 24–25
summarizing RIPv2 routes across, 220–222
dotted decimal format, 24
hexadecimal format, 24
IP addresses, 24
number of required hosts, calculating, 25
RIP, classful routing, 176
subnetting, VLSM
and RIPv2 routing, 218–220
troubleshooting, 236–242
subnetwork dependent functions of IS-IS layered network architecture, 521
Decision process, 531–534
designated routers, 523–524, 526
neighbors, 522–523
Update process, 526–530
Subnetwork Independent sublayer (IS-IS), 521
sub-subnetting, 208
summarization, 677
address aggregation, 293–296
CIDR, 296–297
EIGRP, 655
in redistributed environments, 652–657
interface-specific, 653
null interfaces, 657
of RIPv2 routes, disabling, 221
OSPF
configuring, 435–440
troubleshooting, 463–466
RIP, 177
RIPng, 235
summary addresses, 677
summary routes, 94
summary-address command, 652
supernetting, 95
System ID (IS-IS), 519
system routes, 252
TCP (Transmission Control Protocol), 41–44
ACLs, 790
header information, 42
TCP/IP (Transmission Control Protocol/Internet Protocol), 5
application layer, 6
ARP, 33–34
proxy ARP, 36
data link layer, 6
UDP, 44–45
ICMP Echo Requests/Replies, 39
Internet layer, 6
physical layer, 6
three-way handshaking, 555
timers
EIGRP, multicast flow timer, 265
holddown timers, 144–145
IGRP, 254–255
OSPF, group pacing timer, 377
RIP, 170–172
expiration timer, 171
route invalidation, 140–141
timers active time command, 275
timers basic command, 194
timing jitter, 145
TLA (Top Level Aggregator), 53
TLV (Type/Length/Value) fields, 70
general fields, 289
IP External Routes TLV, 291–293
IP Internal Reachability, U/D bit, 556
IP Internal Routes TLV, 290–291
IP-specific fields, 290
of IS-IS PDUs, 536–539
Area Addresses TLVs, 542–543
Authentication Information TLV, 544
Intermediate System Neighbors TLVs, 543
IP Interface Address TLV, 545
Padding TLV, 543
Protocols Supported TLV, 545
of IS-IS LSPs, 547–548
Inter-Domain Routing Protocol Information, 551
Intermediate System Neighbors, 549
IP External Reachability, 551
IP Internal Reachability, 550–551
topological table, contents of, 268
totally stubby areas, 387
trace command, 12
tracing failed routes, 109–112
IPv6, 120–122
traffic, load balancing, 137
Traffic Class field (IPv6 packets), 59
training classes for CCIE exam, 804
transit networks, 340
transition technologies, 58
triggered updates, 144
RIP, 172
troubleshooting
EIGRP, 317
missing neighbors, 318–323
stuck-in-active neighbors, 323–327
IS-IS, 606
adjacencies, 607–610
link-state database, 607, 610–614
on NBMA networks, 615–619
OSPF, 455–456
adjacencies, 456–458
area-wide problems, 459
isolated areas, 460–463
misconfigured summarization, 463–466
OSPFv3, Frame-Relay mapping, 506–509
RIP, 193
RIPng, misconfigured VLSM, 236–242
RIPv2, misconfigured VLSM, 236–242
static routes, 109
failed routes, 109–112
protocol conflicts, 112, 115–116
subnet masks, 29
TTL (Time to Live) field, 12
Type 1 external paths, 392
Type 2 external paths, 392
types of LSAs, 377
ASBR Summary LSAs, 382
External Attributes LSAs, 385
Group Membership LSAs, 385
Network LSAs, 379–381
Network Summary LSAs, 381–382
NSSA External LSAs, 385
Opaque LSAs, 385
Router LSAs, 378–379
types of traffic in OSPF areas, 369
U/D (Up/Down) bit, 556
UDP (User Datagram Protocol)
ACLs, 791
header information, 44–45
unequal-cost load balancing, EIGRP configuration, 299–302
unequal-cost load sharing, 102
unicast addresses, 174
global addresses, 53
updates, configuring, 182–184
unreachable networks, 144
unspecified addresses, 52
Update process (IS-IS), 526–530
update timers, RIP, 172
updates
EIGRP, 264
invalid, sources of, 210
minimizing impact of, 190–193
nonperiodic, 262
RIP, 172
uptime, 266
Urgent Pointer field, TCP, 44
User Datagram Protocol. See UDP
variables, RIP_JITTER, 170
variance command, 300
verifying EIGRP stub router configuration, 311
Version field
RIP, 173
RIPv2, 202
versions of IP, 8
viewing
IS-IS link-state database, 529–530
IS-IS neighbor table, 523
configuring, 374
IS-IS support, 518
OSPF, configuring, 444–445
VLSM (variable-length subnet masking), 206–209
and RIPv2 routing, 218–220
troubleshooting, 236–242
which-route command, 534
wide metrics, 558
Window Size field, TCP header, 43
windowing, TCP, 42