iii
Configuring OSPF preference ·················································································································· 77
Configuring OSPF route redistribution ····································································································· 78
Advertising a host route ··························································································································· 79
Tuning and optimizing OSPF networks ············································································································ 79
Configuration prerequisites ······················································································································ 79
Configuring OSPF timers ························································································································· 79
Specifying LSA transmission delay ·········································································································· 80
Specifying SPF calculation interval ·········································································································· 81
Specifying the LSA arrival interval ··········································································································· 81
Specifying the LSA generation interval ···································································································· 81
Disabling interfaces from receiving and sending OSPF packets ····························································· 82
Configuring stub routers ··························································································································· 82
Configuring OSPF authentication ············································································································· 83
Adding the interface MTU into DD packets ······························································································ 84
Configuring a DSCP value for OSPF packets ·························································································· 84
Configuring the maximum number of external LSAs in LSDB ································································· 84
Configuring OSPF exit overflow interval ·································································································· 85
Enabling compatibility with RFC 1583 ······································································································ 85
Logging neighbor state changes ·············································································································· 85
Configuring OSPF network management ································································································ 86
Configuring the LSU transmit rate ············································································································ 87
Enabling OSPF ISPF ······························································································································· 87
Configuring prefix suppression ················································································································· 87
Configuring prefix prioritization ················································································································· 88
Configuring OSPF PIC ····························································································································· 88
Configuring the number of OSPF logs ····································································································· 89
Configuring OSPF GR ····································································································································· 89
Configuring OSPF GR restarter ··············································································································· 90
Configuring OSPF GR helper ··················································································································· 91
Triggering OSPF GR ································································································································ 91
Configuring OSPF NSR ··································································································································· 92
Configuring BFD for OSPF ······························································································································ 92
Configuring bidirectional control detection ······························································································· 92
Configuring single-hop echo detection ····································································································· 93
Configuring OSPF FRR ··································································································································· 93
Configuration prerequisites ······················································································································ 93
Configuration guidelines ··························································································································· 93
Configuration procedure ··························································································································· 94
Displaying and maintaining OSPF ··················································································································· 95
OSPF configuration examples ························································································································· 96
Basic OSPF configuration example ········································································································· 96
OSPF route redistribution configuration example ···················································································· 99
OSPF route summarization configuration example ················································································ 100
OSPF stub area configuration example ································································································· 103
OSPF NSSA area configuration example) ····························································································· 106
OSPF DR election configuration example ······························································································ 108
OSPF virtual link configuration example ································································································ 112
OSPF GR configuration example ··········································································································· 114
OSPF NSR configuration example ········································································································· 116
BFD for OSPF configuration example ···································································································· 118
OSPF FRR configuration example ········································································································· 121
Troubleshooting OSPF configuration ············································································································· 123
No OSPF neighbor relationship established ·························································································· 123
Incorrect routing information ·················································································································· 124
Configuring IS-IS ························································································· 125
Overview ························································································································································ 125
Terminology ··········································································································································· 125
IS-IS address format ······························································································································ 125
NET ························································································································································ 126
IS-IS area ··············································································································································· 127
IS-IS network types ································································································································ 128