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Troubleshooting OSPF

1. NSSA ABR not translating Type 7 LSA 2006 Cisco Systems Inc All rights reserved 15 Presentation_ D scr Adjacency Is Not Coming Up Useful Commands for This Problem Show IP OSPF neighbor Show IP OSPF interface Debug IP OSPF adjacency Adjacency Is Not Coming Up Layer 2 is down R3 show ip ospf neighbor R3 R3 show ip ospf interface serial Serial2 is down line protocol i Internet Address 18 10 0 3 30 Area 0 Process ID 1 Router ID 3 3 3 3 Network Type POINT_TO_POINT Cost 64 Transmit Delay is 1 sec State D Timer intervals configured Hello TO Dead 40 Wait 40 Retransmit 5 2006 Cisco Systems Inc All rights reserved 16 Presentation_ D scr Adjacency Is Not Coming Up OSPF not enabled on the interface R3 show ip ospf neighbor R3 ow i eualdi is up line O not enabled on this interface In 12 0 R3 show ip ospf interface serial 2 R3 Tip Check for the wrong network statement re enter the network statement Adjacency Is Not Coming Up Interface is defined as passive R3 show ip ospf neighbor R3 R3 show ip ospf interface e0 Ethernei0 is up line protocol is up Internet Address 192 1 1 3 24 Area 1 Process ID 1 Router ID 3 3 3 3 Network Type BROADCAST Cost 10 Transmit Delay is 1 sec State DR Priority 1 Designated Router ID 192 1 1 4 Interface address 192 1 1 3 No PACE designated router on this network Timer in ed Hello 10 Dead 40 Wait 40 Ret
2. IP MTU large for example 4470 on POS interface Available resources are not used CSCse01519 Available in 12 4 13 12 2 33 SXH 12 2 33 SRB Interface Brief Keyword Show ip ospf interface brief Show ipv6 ospf interface brief r100 sh ipv6 ospf interface brief Interface PID Area Intf ID Lo2147483644 65535 4294967294 21 Lo2147483647 65535 255 255 255 255 22 VL1 6 0 25 VLO 0 24 Se3 0 6 0 14 Lol 6 0 20 Se2 0 6 6 10 Tud 1000 0 19 2006 Cisco Systems Inc All rights reserved Presentation_ID scr Cost State 65535 LOOP 1 LOOP 65535 DOWN 62 P2P 64 DOWN 1 LOOP 62 P2P 11111 DOWN Nbrs F C 0 0 0 0 0 0 1 1 0 0 0 0 1 1 0 0 41 Interface Based OSPF Enable OSPF has traditionally supported enabling the protocol on interfaces by a network command On unnumbered interfaces OSPF automatically assumes the same area as the corresponding numbered interface What if the unnumbered interface is desired to be in a different area e0 ip addr 1 1 1 1 se2 0 ip unnumbered e0 router ospf 1 network 1 1 1 0 255 255 255 0 area 0 Interface Based OSPF Enable Allow an interface specific command to enable OSPF in a different area Interface scoped command has higher precedence This allows to preserve address space A new tool which can be used instead of network command By default secondary addresses are announced can be turned off with an option ip ospf 1 area 1 secondaries no
3. Metric 20 Forwarding address 0 0 0 0 External Route 140 10 0 0 192 1 2 024 R1 Ap ASBR 2 2 2 2 a 114 7 ez 81004 i 192 1 4 0 24 lt m External Type 5 2006 Cisco Systems Inc All rights reserved Presentation _ID scr Forwarding Address Type 5 When Will It Set to Non Zero OSPF is enabled on the ASBR s next hop interface amp amp The ASBR s next hop interface is non passive to OSPF amp amp The ASBR s next hop interface network type is not p2p or p2mp amp amp The ASBR s next hop interface address falls into OSPF network range Type 7 Details R7 show ip ospf database nssa external 140 10 0 0 LS age 156 Options No TOS Capability Type 7 5 translation LS type AS External Link Link State ID 140 10 0 0 External Network Number Advertising Router 7 7 7 7 Router ID of R7 ASBR LS Seq Number 80000001 Initial Seq Number Checksum 0x01A6 Length 36 Network Mask 16 Metric Type 2 Metric 20 Forwarding address 0 0 0 0 External Route 140 10 0 0 3 2 192 1 4 0 24 2006 Cisco Systems Inc All rights reserved Presentation_ID scr Forwarding Address Type 7 When Will It Set to Non Zero OSPF is enabled on the ASBR s next hop interface amp amp The ASBR s next hop interface is non passive to OSPF amp amp The ASBR s next hop interface network type is not p2p or p2mp amp amp The ASBR s next hop interface address falls into OSPF net
4. LS age 0 Always 0 at origination Options No TOS capability LS type Router Links This is a router LSA 1 Link State ID 3 3 3 3 Router ID of R3 Advertising Router 3 3 3 3 Router ID of R3 LS Seq Number 80000001 Initial Seq Number a S TS 192 1 4 0 24 Area Border Router bitB 1 Number of links 2 Link Connected to another Router point to point Link ID Neighboring Router ID 6 6 6 6 Link Data Router Interface address 18 10 0 5 Number of TOS metrics 0 TOS 0 Metric 8 Link Connected to a Stub Network Link ID Network subnet number 18 10 0 4 Link Data Network Mask 255 255 255 252 Number of TOS metrics 0 TOS 0 Metric 8 Router Link Types Summary Point to Point Neighbors Interface IP Numbered RID Address 1 Point to Point Neighbors MIB II Ifindex Unnumbered RID Value lt IP Address Interface IP 2 Ten of the DR Address IP Network 3 Stub Nabe Subnet Mask c Neighbors Interface IP 4 Virtual Link RID Address 2006 Cisco Systems Inc All rights reserved Presentation_ID scr Network LSA for 192 1 1 0 R3 show ip ospf database network 192 1 1 4 Network Link States Area 1 LS age 948 Options No TOS Capability LS type Network Links Link State ID 192 1 1 4 address of Designated Router Advertising Router 4 4 4 4 RID of DR LS Seq Number 80000001 Initial Seq Number Checksum 0x9A84 Length 40 Network Mask 24 Attached Router 4 4 4 4 Attached Router 3 3 3 3 Attached Route
5. SPF algorithm executed 38 times SPF calculation time Delta T Intra D Intra Summ D Summ Ext D Ext Total Reason 00 22 00 0 0 0 0 0 0 0 RN SN 00 21 44 0 0 4 0 0 0 4 R SN X 00 21 34 0 0 4 0 0 o0 4 R SN X 00 21 24 0 0 0 4 0 o0 4 RSN X 0 0 0 0 0 0 0 00 21 04 0 0 0 0 0 o 0 RN SN 00 20 54 0 0 0 0 0 0 0 x 00 20 44 0 0 4 0 0 0 4 R SN X 00 20 34 0 0 0 0 0 0 0 x 00 00 17 4 0 0 0 0 0 4 R N SN SA X R Router LSA N NetworkLSA SN Summary Network LSA SA Summary ASBR LSA X External LSA 2006 Cisco Systems Inc All rights reserved Presentation_ D scr ra Show IP OSPF Stat Requires Enable Mode R1 show ip ospf stat detail OSPF process ID 100 Area 0 SPF algorithm executed times SPF 1 executed 1w0d ago SPF type Full SPF calculation time in msec SPT Intra D Intr Summ D Summ Ext7 D Ext7 Total 0 0 0 0 0 0 LSIDs processed R 1 N 0 Stub 1 SN 0 SA 0 X7 0 Change record R LSIDs changed 1 ast 10 LSIDs 4 4 4 4 R Summary OSPF SPF statistic SPF calculation time Delta T Intra D Intra Summ D Summ Ext D Ext Total Reason iw0d 0 0 0 0 0 0 0 R SPF Running Constantly R3 deb ip ospf mon OSPF edule SP a Change in LS ID 1 1 1 1 LBA type R OSPF schedule SPF spf_time Oms wait_interval 861421816s OSPF Begin SPF at 0x33585480ms process time 752ms spf_time Oms wait_interval 861421816s OSPF End SPF at 0x33585488ms Total elapsed time 8ms Intra 4ms Inter Oms External Oms 2006 Cisco Systems Inc
6. All rights reserved Presentation_ D scr SPF Running Constantly R3 show ip ospf database OSPF Router with ID 3 3 3 3 Process ID 1 Router Link States Area 0 LinkID ADV Router Age Seq Checksum Link count 3 3 3 3 3 3 3 3 106 Ox80000009 OxC3F1 3 Summary Net Link States Area 0 LinkID ADV Router Seqi Checksum 18 10 0 0 7 7 7 7 3 ADNA 0x80000008 0x3DC2 18 10 0 0 8 8 8 8 1396 0x80000004 0x27D8 Router Link States Area 1 LinkID ADV Router Seq Checksum Link count 1 1 1 1 1 1 1 1 0x80000016 OxE6CD 2 NSSA ABR Not Translating Type 7 LSA Only NSSA ABR with the highest RID does the conversion Type 7 5 Conversion 2006 Cisco Systems Inc All rights reserved 36 Presentation_ID scr NSSA ABR Not Translating Type 7 LSA Only NSSA ABR with the highest RID does the conversion Common Issues 2006 Cisco Systems Inc All rights reserved Presentation_ID scr 37 I Interface Scoped Debugging Enhancement in limiting the OSPF debug output to just a selection of interfaces Example below will generate debug output for only two interfaces specified below debug condition interface Ethernet 0 0 debug condition interface Ethernet 1 0 debug ip ospf hello debug ip ospf adjacency Available in 12 4 4 T 12 2 30 S 12 0 32 S debug ip ospf flood Further enhancement to allow an access list filter and a detail option for verbose output Available in 12 4 4 T 12 2 30 S 12 0 32 S debug
7. Inc All rights reserved Presentation _ID scr 46
8. ip ospf packets Available in 12 4 10 12 2 33 SXH 12 2 33 SRB OSPF Traffic Statistics show clear ip ospf process id traffic interface Output consists of router2 show ip ospf traffic Global summary section OSPF statistics Revd 29 total 0 checksu errors Per process sections 7 Hello 8 database desc 2 link state req 8 link state updates 4 link state acks OSPF queues Sent 29 total i 8 Hello 6 database desc 2 link state req Interface details 8 link state updates 5 link state acks Per process summary Available in 12 4 6 T 12 0 28 S 12 2 30 S OSPFv3 support in 12 2 31 SB 2006 Cisco Systems Inc All rights reserved 38 Presentation _ID scr OSPF Traffic Statistics Per Process Summary Summary traffic statistics for process ID 1 OSPF packets received sent Type Packets Bytes 0 RX Invalid 0 RX Hello 8 384 RX DB des 8 496 RX LSreq 2 72 HX LS upd 8 740 RX LS ack 4 236 RX Total 30 1928 Per process filter TXFailed 0 0 sh ip ospf lt process_id gt traffic TX Hello 10 792 TX DB des 6 624 TXLSreq 2 112 TXLS upd 8 708 TXLS ack 5 460 TX Total 31 2696 OSPF header errors Length 0 Checksum 0 Version 0 Bad Source 0 No Virtual Link 0 Area Mismatch 0 No Sham Link 0 Self Originated 0 Duplicate ID 0 Hello 0 MTU Mismatch 0 Nbr Ignored 0 LLS 0 Authentication 0 TTL Check Fail 0 OSPF LSA errors Type 0 Length 0 Data 0 Checksum 0 OSPF Traffic Statistics Queue
9. 5 30 Area 0 Process ID 1 Router ID 3 3 3 3 Network Typ POINT TO POINT Cost 64 R6 show ip ospf interface serial 0 SerialO is up line protocol is up Internet Address 18 0 0 6 30 Area 0 Process ID 1 Router ID 6 6 6 6 Network Typ BROADCAST Cost 64 2006 Cisco Systems Inc All rights reserved 28 Presentation_ID scr Mismatched Network Types Cont R3 show ip ospf database router 3 3 3 3 Link ID 6 6 6 6 Router id of the neighbor Link Data 18 10 0 5 IP interface address This is a point to point link TOS metrics 0 metric 8 18 10 0 4 30 R6 R3 show ip ospf database router 6 6 6 6 LinkID 18 10 0 6 IP address of the DR Link Data 18 10 0 6 Interface address This is a transit link metrics 0 metric 8 Point to Point Numbered and Unnumbered Links 192 1 4 1 R3 18 10 0 4 30 R6 R3 show ip ospf neighbor Neighbor ID Pri Dead Time Address Interface 6 6 6 6 1 00 00 30 18 0 0 6 SerialO R3 show interface serialO SerialO is up line protocol is up Hardware is HD64570 Cinterface is unnumbered sing address of Ethernet1 192 1 4 1 R6 show interface serialO Serial is up line protocol is up Hardware is HD64570 Internet address i 18 10 0 6 30 2006 Cisco Systems Inc All rights reserved Presentation_ID scr 29 T Point to Point Numbered and Unnumbered Links Cont R3 show ip ospf database router 3 3 3 3 Router id of the neighbor MIBII Ifindex Value Th
10. Dead tin in 00 00 39 CNeighbor is up for 00 06 30 Index 0 0 retransmission queue length 0 number of retransmission 0 First 0x0 0 0x0 0 Next 0x0 0 0x0 0 Last retransmission scan length is 0 maximum is 0 Last retransmission scan time is 0 msec maximum is 0 msec Neighbor 2 2 2 2 interface address 192 1 1 2 In the area 1 via interface FastEthernet0 0 Neighbor priority is 1 State is FULL 6 state changes DR is 192 1 1 4 BDR is 192 1 1 2 Options is 0x42 Dead timer due in 00 00 38 Neighbor is up for 00 06 31 Index 2 2 retransmission queue length 0 number of retransmission 0 First 0x0 0 0x0 0 Next 0x0 0 0x0 0 Last retransmission scan length is 0 maximum is 0 Last retransmission scan time is 0 msec maximum is 0 msec Show IP OSPF Interface R3 show ip ospf interface FastEthernet0 0 is up line Internet Addres lt 192 1 1 3 24 Area Process ID 1 Router ID 5 3 Network Type BROADOAST East 1 Transmit Delay is 1 sec State DROTHER Priority Designated Router ID 4 4 4 4 Interface address 192 1 1 4 Backup Designated router ID ddress 192 1 1 2 Timer interva onfigured Hello 10 Dead 40 Wait 40 5 Index 1 1 flood queue length 0 Next 0x0 0 0x0 0 Last flood scan length is 0 maximum is 5 Last flood scan time is 0 msec maximum is 0 msec Neighbor Count is 3 Adjacent neighbo Adjacent with neighbor 2 2 2 2 Backup Designated Router Adjacent with neighbor 4 4 4 4 Designated Router Suppress hello f
11. ID 3 3 3 3 od Hello RID 6 6 6 6 N 3 3 3 3 a DBD MTU 1500 flag 0x7 Seq 1E55 DBD MTU 1500 flag Lo Seq 22AB Stuck in EXSTART EXCHANGE Useful in debugging defines M and MS bits OSPF Send DBD to 141 108 97 1 on Serial0 seq 0xBC4 opt 0x2fag 0x3 len 492 Flag 0x7 gt 111 means I Initial 1 M 1 More MS 1 Master Flag 0x6 gt 110 not possible Flag 0x5 gt 101 not possible Flag 0x4 gt 100 not possible Flag 0x3 gt 011 means master has more data to send Flag 0x2 gt 010 means slave has more data to send Flag 0x1 gt 001 means master has no more data left to send Flag 0x0 gt 000 means slave has no more data left to send Lee be Pelt ee 2006 Cisco Systems Inc All rights reserved Presentation_ ID scr 25 Stuck in EXSTART EXCHANGE Reasons MTU mismatch EXCHANGE Note If Cisco IOS is lt 12 0 3 neighbor will show stuck in EXCHANGE Neighbor RID is same as ours EXSTART Note If Cisco IOS is gt 12 0 7 it displays msg OSPF 3 DUP_RTRID and OSPF neighbor list will be empty Unicast is broken EXCHANGE 1 Wrong VC DLCi mapping in frame ATM environment in highly redundant network 2 MTU problem can t ping across with more than certain length packet 3 Access list blocking unicast after two way OSPF send unicast packet except p2p links 4 NAT is translating unicast packet Between PRI and BRi dialer and network type i
12. RE e 1 Troubleshooting OSPF BRKRST 3310 2006 Cisco Systems Inc All rights reserved Presentation_ID scr Networkers fre Ld ET efo cen Cisco Networkers l Agenda LSA Overview Troubleshooting Commands Common Issues Troubleshooting Enhancements LSA Overview 2006 Cisco Systems Inc All rights reserved Presentation_ID scr LSA Type Review 1 Router Network Summary Network Summary ASBR External Greup Membership NSSA oOo N DO a fF WO ND 9 11 Opague Router LSA of R3 for Area 1 R3 show ip ospf database router 3 3 3 3 Router Link States Area 1 LS age 0 Always 0 at origination Options No TOS capability LS type Router Links This is a router LSA 1 Link State ID 3 3 3 3 Router ID of R3 Advertising Router 3 3 3 3 Router ID of R3 LS Seq Number 80000001 Initial Seq Number Checksum 0x146B Length 48 192 1 4 0 24 Area Border Router bit B 1 Number of links 2 Link Connected to a Transit Network Link ID Designated Router address 192 1 1 4 Link Data Router Interface address 192 1 1 3 Number of TOS metrics 0 TOS 0 Metric 1 Link Connected to a Stub Network Link ID Network subnet number 192 1 4 0 Link Data Network Mask 255 255 255 0 Number of TOS metrics 0 TOS 0 Metric 2 2006 Cisco Systems Inc All rights reserved Presentation_ D scr Router LSA of R3 for Area 0 Cont Router Link States Area 0
13. ary Net Link States Area 0 LinkID ADV Router Age Seq Checksum 18 10 0 0 7 7 7 7 3 DNA 0x80000008 0x3DC2 18 10 0 0 8 8 8 8 1396 0x80000004 0x27D8 Router Link States Area 1 LinkID ADV Router Age Seq Checksum Link count 1 1 1 1 1 1 1 1 671 0x80000016 OxE6CD 2 2006 Cisco Systems Inc All rights reserved Presentation _ID scr Show IP OSPF Database Database Summary R3 show ip ospf database database summary OSPF Router with ID 3 3 3 3 Process ID 1 Area 0 database summary e Count Delete Maxage 6 0 0 4 0 0 0 0 Summary A 0 0 0 Type 7 Ext 0 0 0 Opaque Link 0 0 0 Opaque Area 0 0 0 Subtotal 20 0 0 Area 1 database summary LSA Type Count Delete Maxage Router 4 0 0 Network 1 0 0 Summary Net 10 0 0 0 0 Summary ASBR 4 Show IP OSPF Neighbor R3 show ip ospf neighbor Heighbor Dr State Bead Time Address Interface 1 1 1 1 FULL DROTHER 00 00 33 192 1 1 1 FastEthernet0 0 2 2 2 2 1 FULL DROTHER 00 00 32 192 1 1 2 FastEthernet0 0 4 4 4 4 1 FULL DR 00 00 39 192 1 1 4 FastEthernet0 0 6 6 6 6 1 FULL 00 00 38 18 10 0 6 SerialO 0 R3 192 1 4 0 24 2006 Cisco Systems Inc All rights reserved Presentation_ID scr 10 Show IP OSPF Neighbor Detail R3 show ip ospf neighbor detail Neighbor 1 1 1 1 interface address 192 1 1 1 In the area 1 Via interface FastEthernet0 0 Neighbor priority is 1 State is 2WAY state changes DR is 192 1 1 4 BDR is 192 1 1 2 Options i 0x2 gt
14. e are not OSPF 4 ERRRCV Received invalid packet_mismatch area ID from backbone ernetO area must be virtual link but not found from 192 1 1 4 2006 Cisco Systems Inc All rights reserved 19 Presentation_ D scr Adjacency Is Not Coming Up Mismatched transit stub NSSA option 8 8 8 8 7 7 7 7 48 49 0 1 81002 88 8 8 amp Area 2 a Area 2 NSSA R8 R7 show ip ospf neighbor R7 R7 debug ip ospf adj OSPF adjacency events debugging is on OSPF Hello from 18 10 0 2 witkcmismatched Stub Transit area option bit Options Normal area OSPF Send DBD to 141 108 97 1 on Serialo seq 0xBC4Gpt 0x2 Dag 0x3 len 492 E bit is 1 Allow externals option 0x2 HEX 00000010 Bin Stub area OSPF Send DBD to 141 108 97 1 on Serial0 seq 0x186 opt 0x0 Jag 0x3 len 372 E bit is 0 no external allowed options 0x0 00000000 NS SA ospF Send DBD to 141 108 97 1 on Serialo seq 0x11 opt 0x8 Wag 0x3 len 372 N P bit is on options 0x8 00001000 DC OSPF Send DBD to 141 108 97 1 on SerialO seq Ox1A1 T 0x3 len 392 DC bit is negotiated options 0x20 00100000 Jo eoleo e 2006 Cisco Systems Inc All rights reserved 20 Presentation_ ID scr OSPF Neighbor Stuck in State Useful Commands for This Problem Show IP OSPF neighbor Debug IP OSPF adjacency OSPF Adjacency States ATTEMPT INIT 2 WAY EXSTART EXCHANGE LOADING FULL 2006 Cisco Systems Inc All rights reserved 21 Presentation_ID
15. ires Enable Mode R1 show ip ospf stat detail OSPF process ID 100 Area 0 SPF algorithm executed times gt SPF 1 executed 1w0d ago SPF type Full SPF calculation time in msec SPT Intra D Intr Summ D Summ Ext7 D Ext7 Total 0 0 0 0 0 0 0 LSIDs processed R 1 N 0 Stub 1 SN 0 SA 0 X7 0 Change record R LSIDs changed 1 ast 10 LSIDs 4 4 4 4 R Summary OSPF SPF statistic SPF calculation time Delta T Intra D Intra Summ D Summ Ext D Ext Total Reason iw0d 0 0 0 0 0 Show IP OSPF Borders R3 show ip ospf borders routers OSPF Process 1 internal Routing Table Codes i Intra area route Inter area route i 4 4 4 4 1 via 192 1 1 4 FastEthernet0 0 BR Area 0 SPF 42 i 4 4 4 4 1 via 192 1 1 4 FastEthernet0 0 ABR Area 1 SPF 38 i 8 8 8 8 10 via 18 10 0 6 Serial0 0 ABR ASBR Area 0 SPF 42 i 7 7 7 7 17 via 192 1 1 4 FastEthernet0 0 ABR ASBR Area 0 SPF 42 2006 Cisco Systems Inc All rights reserved Presentation_ D scr Other Show Commands BRKAST 2310 a 14451_04 2008 c2 2008 Cisco Systems Inc All rights reserved Cisco Public 27 Other Show Commands Cont BRKRST 2310 28 14451 04 2008 c2 2008 Cisco Systems Inc All rights reserved Gisco Public 28 2006 Cisco Systems Inc All rights reserved 14 Presentation_ID scr Common Issues Common Issues Adjacency is not coming up OSPF neighbor stuck in State Information is in the DB but not in the RT SPF running constantly
16. is is a point to point link Link Data Type 1 192 1 4 1 J e 18 10 0 4 30 metric 8 R6 R3 show ip ospf database router 6 6 6 6 ou Router id of the neighbor IP interface address This is a transit link Link Data Type 1 TO etri metric 8 TER Different Mask or IP Subnet on P2P Links R3 show ip ospf neighbor Neighbor ID Pri Dead Time Address Interface 6 6 6 6 1 00 00 30 18 0 0 6 Serial R3 show interface serial 0 Serial0 is up line protocol is up Hardware is HD64570 Internet address is 9 10 0 5 24 R6 show interface serial 0 SerialO is up line protocol is up Hardware is HD64570 Internet address i 18 10 0 6 30 2006 Cisco Systems Inc All rights reserved 30 Presentation_ D scr Different Mask or IP Subnet on P2P Links Cont R3 show ip ospf database router 3 3 3 3 Router id of the neighbor Interface address This is a point to point link metric 8 R3 show ip ospf database router 6 6 6 6 Router id of the neighbor Interface address This is a point to point link metric 8 Address Flipped on Dual Links R3 show ip ospf neighbor Neighbor ID Pri Dead Time Address Interface 6 6 6 6 1 00 00 30 18 10 0 6 Serial 6 6 6 6 1 00 00 33 18 10 0 22 Seriali R3 show interface serial 0 SerialO is up line protocol is up Hardware is HD64570 Internet address i 18 10 0 21 30 2006 Cisco Systems Inc All rights reserved 31 Presentation_ D scr F
17. ne Available in 12 3 11 T 12 2 28 SB 12 0 29 S 2006 Cisco Systems Inc All rights reserved Presentation_ D scr e0 ip addr 1 1 1 1 se2 0 ip unnumbered e0 ip ospf 1 area 1 router ospf 1 network 1 1 1 0 255 255 255 0 area 0 42 OSPF Graceful Shutdown OSPF Graceful Shutdown Technique of removing an OSPF router from a network with minimal disruption to the network OSPF configuration is retained When router enters the shutdown mode it informs all other routers in the network about this event Floods it s own maxed router lsa in each area Sends Hello packet with no neighbors listed on all it s interfaces OSPF process does not perform any activity when shutdown OSPF packets received on any interface are dropped No OSPF packets are sent Only configuration changes are processed 2006 Cisco Systems Inc All rights reserved 43 Presentation_ D scr L OSPF Graceful Shutdown Cont Router Mode command no shutdown Per interface shutdown is also available Hello packet with no neighbors is sent on interface Link s associated with the interface are removed from Router LSA Network LSA is flushed for broadcast segment OSPF operation is disabled on the interface OSPF configuration is retained Interface Mode command no ip ospf shutdown Available in 12 2 33 SRC Summary What We Learned Overview of OSPF LSAs Different troubleshooting commands and what to look for in tho
18. or 0 neighbor s 2006 Cisco Systems Inc All rights reserved 11 Presentation_ ID scr Show IP OSPF Virtual Links R3 show ip ospf virtual link Virtual Link OSPF_VLO toTouter 4 4 4 4 is up Run as demand circuit DoNotAge LSA allowed Transit area 1 via interface FastEthernet0 0 Cost of using 1 Transmit Delay is 1 sec State POINT TO POINT Timer DRE configured Hello 10 Dead 40 Wait 40 Retransmit 5 Hello due in 00 00 09 Adjacency State FULL Hello suppressed Index retransmission queue length 0 number of retransmission 1 First 0x0 0 0x0 0 Next 0x0 0 0x0 0 Last retransmission scan length is 1 maximum is 1 Last retransmission scan time is 0 msec maximum is 0 msec R3 Show IP OSPF Stat Requires Enable Mode R3 sh ip ospf stat Area 0 SPF algorithm executed 42 times Area 1 SPF algorithm executed 38 times SPF calculation time Delta T Intra D Intra Summ D Summ Ext D Ext Total Reason 00 22 00 0 0 0 0 0 0 0 R N SN 00 21 44 0 0 4 0 0 0 4 R SN X 00 21 34 0 0 4 0 0 0 4 R SN X 00 21 24 0 0 0 4 0 0 4 R SN X 0 Do 0 0 0 0 0 0 gt 00 21 04 0 0 0 0 0 0 0 R N SN 00 20 54 0 0 0 0 0 0 0 X 00 20 44 0 0 4 0 0 0 4 R SN X 00 20 34 0 0 0 0 0 0 0 X 00 00 17 4 0 0 0 0 0 4 R N SN SA X R Router LSA N NetworkLSA SN Summary Network LSA SA Summary ASBR LSA X External LSA 2006 Cisco Systems Inc All rights reserved Presentation_ ID scr 12 Show IP OSPF Stat Requ
19. orwarding Address Problem External Route 140 10 0 0 4 R5 18 10 0 9 29 pz Ri show ip ospf database external 140 10 0 0 Link State ID 140 10 0 0 Advertising Router 5 5 5 5 Network Mask 255 255 0 0 f orwarding address 18 10 0 10 Ri show ip route 18 10 0 10 Routing entry for 18 10 0 8 29 Known via ospf 1 distance 110 metric 20 pe extern 2 7 forward metric 10 Forwarding Address Problem External Route 140 10 0 0 ee 5 18 10 0 9 29 R7 R5 router ospf 1 network 18 10 0 0 0 0 0 255 area 1 redistribute rip subne router rip network 10 0 0 0 R4 router asp area 1 range 18 10 0 0 255 255 255 240 gt 2006 Cisco Systems Inc All rights reserved Presentation _ID scr 32 Discontigous Backbone Summary Summary LSA LSA R1 and R2 are not be able to see each other Summary LSA for inter area routes must not be generated into the backbone The solution is to create virtual link between ABR1 and ABR2 SPF Running Constantly Useful Commands for This Problem Show IP OSPF stat Show IP OSPF database Show IP OSPF database database sum 2006 Cisco Systems Inc All rights reserved 33 Presentation_ID scr SPF Running Constantly Reasons LSA Flaps Due To Duplicate RID IP address Constant link flapping in an area SPF Running Constantly Requires Enable Mode R3 sh ip ospf stat Area 0 SPF algorithm executed 42 times Area 1
20. r 2 2 2 2 Attached Router 1 1 1 1 192 1 4 0 24 Type 3 Details R4 show ip ospf database summary 192 1 2 0 Summary Net Link States Area 0 LS age 1514 Options No TOS Capability LS type Summary Links Networks Link State ID 192 1 2 0 Summary Network Number Advertising Router 4 4 4 4 RID of ABR LS Seq Number 80000001 Initial Seq Number Checksum 0xFC68 Length 28 Network Mask 24 TOS 0 Metric 4 OIA ABR 192 12 0 24 metric 4 192 1 2 0 24 192 1 4 0 24 2006 Cisco Systems Inc All rights reserved Presentation _ID scr Type 4 Details R4 show ip ospf database asbr summary 7 7 7 7 Summary ASB Link States Area 0 LS age 1548 Options No TOS Capability LS type Summary Links AS Boundary Router Link State ID 7 7 7 7 As Boundary Router address Advertising Router 4 4 4 4 RID of ABR LS Seq Number 80000001 Initial Seq Number Checksum 0x93E2 Length 28 Network Mask 0 TOS 0 Metric 16 Type 4 Summary 1 1 1 1 a External Route eas lt 140 10 0 0 192 1 2 024 R1 N _Aip ASBR 192 1 4 0 24 Type 5 Details R4 show ip ospf database external 140 10 0 0 LS age 156 Options No TOS Capability LS type AS External Link Link State ID 140 10 0 0 External Network Number Advertising Router 7 7 7 7 Router ID of R7 LS Seq Number 80000001 Initial Seq Number Checksum 0x93E2 Length 36 Network Mask 16 Metric Type 2 bit E 1 gt O E2 Default
21. ransmit 5 No Hellos Passive interface 2006 Cisco Systems Inc All rights reserved 17 Presentation_ ID scr E Adjacency Is Not Coming Up Mismatched subnet mask R3 show ip ospf neighbor R3 R3 debug ip ospf adj OSPF adjacency events debugging is on R3 OSPF Mismatched hello parameters trom Dead R 40 C 40 Hello R 10 C40 Mask R 255 255 255 192 C 255 255 255 0 Adjacency Is Not Coming Up Mismatched hello dead interval R3 show ip ospf neighbor R3 R3 debug ip ospf adj OSPF adjacency events debugging is on R3 OSPF Mismatched hello parameters from 192 1 1 4 Dead R 40 C HS R 15 C T0 Mask R 255 255 255 0 C 255 255 255 0 R4 config if interface ethernet 0 R4 config if no ip ospf hello interval 15 Tip Default is 10 second on LAN 2006 Cisco Systems Inc All rights reserved 18 Presentation_ D scr E Adjacency Is Not Coming Up Mismatched authentication key R3 show ip ospf neighbor R3 R3 debug ip ospf adj OSPF adjacency events debugging is on R3 OSPF Rev pkt from 192 1 1 4 EthernetQ lt Mismatch Authentication Key lt Clear Text Tip Watch for the space at the end of the authentication key E Adjacency Is Not Coming Up Mismatched area ID R4 show ip ospf neighbor R4 R4 debug ip ospf adj OSPF adjacency events debugging is on OSPF Rev pkt from 192 1 1 4 Ethernet0 area 0 0 0 1 mismatch area 0 0 0 2 imthe header neighbor is in area 2 but w
22. s InputQ UpdateQ OutputQ Limit 0 200 0 Drops 0 8881 0 Max delay msec 1076 21188 28 Max size 3961 200 6 Invalid 0 0 0 Hello 3961 0 0 DB des 0 0 0 LS req 0 0 0 LS upd 0 200 0 LS ack 0 0 6 Current size 0 0 0 Invalid 0 0 0 Hello 0 0 0 DB des 0 0 0 LS req 0 0 0 LS upd 0 0 0 LS ack 0 0 0 2006 Cisco Systems Inc All rights reserved Presentation_ID scr 39 OSPF Traffic Statistics Interface Details Interface Serial2 0 OSPF packets received sent Type Packets RX Invalid 0 RX Hello 8 RXDBdes 8 RXLSreq 2 RXLSupd 8 RXLSack 4 RX Total 30 TX Failed 0 TX Hello 10 TXDBdes 6 TXLSreq 2 TXLSupd 8 TXLSack 5 TX Total 31 Interface Related Enhancements 2006 Cisco Systems Inc All rights reserved Presentation_ID scr Bytes 0 384 496 72 740 236 1928 792 624 112 708 2696 Per interface filter Show clear ip ospf traffic lt if_name gt Available in 12 4 6 T 12 0 28 S OSPF header errors Length 0 Checksum 0 Version 0 Bad Source 0 No Virtual Link 0 Area Mismatch 0 No Sham Link 0 Self Originated 0 Duplicate ID 0 Hello 0 MTU Mismatch 0 Nbr Ignored 0 LLS 0 Authentication 0 TTL Check Fail 0 OSPF LSA errors Type 0 Length 0 Data 0 Checksum 0 40 OSPF Packet Size Honors IP MTU Default OSPF packet size 1500B IP MTU small for example 1400 in IPSec environment OSPF builds 1500B packet IP code does packet fragmentation Increase in CPU load and pps rate
23. s p2p EXCHANGE Stuck in LOADING 3 3 3 3 2 R3 LS Req LS Type Link State ID Advertising Router LS Update x LSAs 2006 Cisco Systems Inc All rights reserved Presentation_ID scr 26 Stuck in LOADING Reasons LS request is being made and neighbor is sending bad packet or mem corrupt a Do show IP OSPF bad to see bad LSA b Show log will show OSPF 4 BADLSATYPE msg LS request is being made and neighbor is ignoring the request MTU mismatch problem RFC 1583 and 2178 compatibility issue CSCee23634 R OSPF should detect if the neighbor MTU is smaller than ours Currently available in latest 12 3 and 12 0S Stuck in LOADING 3 3 3 3 6 6 6 6 es MTU 2048 MTU 4470 R3 R6 Cisco IOS Cisco IOS 11 3 10T tSReq T 12 0 7T RFC 1583 LS Type RFC 2178 Link State ID Advertising Router LS Update LSAs LSAs 2006 Cisco Systems Inc All rights reserved 27 Presentation_ID scr I Information Is in the DB But Not in the RT Useful Commands for This Problem Show IP OSPF interface lt interface gt Show IP OSPF database lt x gt Where x can be router network summary summary asbr external NSSA Mismatched Network Types R3 18 10 0 4 30 R6 R3 show ip ospf neighbor Neighbor ID Pri Dead Time Address Interface 6 6 6 6 1 00 00 30 18 0 0 6 SerialO R3 show ip ospf interface serial 0 Serial is up line protocol is up Internet Address 18 0 0
24. scr Stuck in ATTEMPT 3 3 3 3 R3 Hello Hello Stuck in ATTEMPT Reasons Our hellos are getting lost in NBMA cloud Neighbor hellos are getting lost in NBMA cloud We received neighbor s hello but rejects it for some reason Misconfigured neighbor statement Broken Unicast 2006 Cisco Systems Inc All rights reserved 22 Presentation_ID scr Stuck in INIT Hello RID 1 1 1 1 Hello RID 2 2 2 2 Hello RID 1 1 1 1 N 2 2 2 2 Hello RID 2 2 2 2 Stuck in INIT Reasons One side is blocking the hello packet with access list One side is translating NAT OSPF hello One side multicast capabilities is broken Layer 2 Dialer map or Frame Relay map is missing keyword broadcast LLS capability issue when Cisco IOS is upgraded 2006 Cisco Systems Inc All rights reserved 23 Presentation_ D scr Stuck in 2 WAY Hello RID 1 1 1 1 P 0 Hello RID 2 2 2 2 P 0 N 1 1 1 1 Hello RID 1 1 1 1 P 0 N 2 2 2 2 Stuck in 2 WAY Reasons This is normal in broadcast network types This is to reduce the amount of flooding on the wire Problem can happen if all the router are configured with priority equal to 0 Only low end routers should be configured with priority 0 so they don t participate in DR election 2006 Cisco Systems Inc All rights reserved 24 Presentation_ D scr Stuck in EXSTART EXCHANGE 3 3 3 3 Koma 6 6 6 6 k R3 Hello EE R
25. se commands Common issues in OSPF networks e g adjacency problems information in the database but not in RT SPF problems and NSSA problems and how to correct those problems OSPF Troubleshooting Enhancements including debugs and interface based enhancements 2006 Cisco Systems Inc All rights reserved 44 Presentation_ D scr More Information White Papers ii Web and Mailers Cisco Press RTFB pmm IP Routing Protocols The campr rhenana haneden gui nodving IP routang probleme CCO OSPF Page C http www cisco com en US tech tk365 tk480 me ea tsd_technology_support_sub protocol_home html RTFB Read the Fine Book Customer Support Mailing List tac cisco com 2006 Cisco Systems Inc All rights reserved Presentation_ID scr T Complete Your Online Session Evaluation Give us your feedback and you could win Don t forget to activate fabulous prizes Winners announced daily your virtual account for access to Receive 20 Passport points for each session all session material evaluation you complete on demand and return for our live virtual event Complete your session evaluation online now in October 2008 open a browser through our wireless network Go to the Collaboration to access our portal or visit one of the Internet Zone in World of stations throughout the Convention Center Solutions or visit d Afafe CISCO 2006 Cisco Systems
26. work range f the above are true then we set the fwd_addr to the next hop addr otherwise If the next hop interface is passive or non multi access use our own IP address on the next hop interface else Use one of the loopbacks if it s up and OSPF is enabled in the area we re announcing to If no loopbacks in that area use the address of the first interface in that area Troubleshooting Commands 2006 Cisco Systems Inc All rights reserved Presentation_ID scr Show IP OSPF R3 show ip ospf Routing Process ospf 1 with D 3 3 3 Dand Domain ID 0 0 0 1 Supports only single TOS TOSO routes Supports opaque LSA ETS an area border router gt SPF schedule delay 5 secs Hold time between two SPFs 10 secs Minimum LSA interval 5 secs Minimum LSA arrival 1 secs Number of external LSA 1 Checksum Sum 0x3B57 Number of opaque AS LSA 0 Checksum Sum 0x0 Number of DCbitless external and opaque AS LSA 0 ge external and opaque AS LSA 0 mber of areas in this router is 22 normal 0 stub 0 nssa Area ranges are Number of LSA TZ gt Checksum Sum 0x686B5 Number of opaque link LSA 0 Checksum Sum 0x0 Number of DCbitless LSA 0 Number of indication LSA 0 Number of DoNotAge LSA 9 Flood list length 0 Show IP OSPF Database R3 show ip ospf database OSPF Router withdD 3 3 3 3 Process ID 1 gt Router Link States Area 0 LinkID ADV Router Age Seq Checksum Link count 3 3 3 3 3 3 3 3 106 0x80000009 OxC3F1 3 Summ

Troubleshooting OSPF

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