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R&S lab ospf nei challenges

dchen0999
Level 1
Level 1

Hi, All,

It is flappy and wierd. Anyone can shed some lights?

Thanks.

Senario:

r3 hub s0/0.235 mul use nei statement - r2, r5 spoke s0/0

Problem:

1. r2 and r5 or either r2 or r5 no route from other ospf areas.

2. using "ip os ne p-mp" or "ip os ne br" or "use all physical interfaces" is fine

Note:

// osp r5 no full route

1. change router id from 2.2.5.5 to 5.5.5.5 for all routers. cle ip os proce: not working

2. reboot r3/2/5 routers: not working (r3 sub-int multipoint not working; r3 physical int works)

3. change nei statment to ip os ne p-mp: it works.

4. change from ip os ne p-mp to ip os ne p-p: not working

5. cle ip os pro for r2/3/5: still not working

6. put it back: ip os ne p-mp: it is fine.

7. however, it is required to use nei statement.

21 Replies 21

Giuseppe Larosa
Hall of Fame
Hall of Fame

Hello Dengming,

you should post the exact text of the scenario description to understand what are the requirements and the constraints.

About point-to-multipoint and neighbor command:

a Cisco proprietary version exists that is called point-to-multipoint non-broadcast.

That mode not using multicast hellos requires to use neighbor command

not receiving routes from other areas:

this should call for a totally stub area.

hub router should be ABR(0, totallystub_area)

Hope to help

Giuseppe

thanks Giuseppe.

Senario:

1. r3 hub s0/0.235 mul - r2, r5 spoke s0/0 ospf area 0: requires to use nei statement on r3

2. R3 connects to multiple ospf areas.

Problem:

r2 and r5 or either r2 or r5 gets no routes from other ospf areas

Note:

I think this is standard ospf implementation with nei statement, but it turns out it is no easy job to get it work.

ip os ne p-p = always works

ip os ne p-mp = works fine

ip os ne br = works fine

nei = works fine for hub physical interface mode

nei = NOT working or not stable in hub sub-interface mode, that is, either both spoke routers or one of the spoke router gets no route from ospf other areas.

This is wierd.

// no router with r3 using nei statement

r3#conf t

Enter configuration commands, one per line. End with CNTL/Z.

r3(config)#router os 1

r3(config-router)#nei 2.2.12.12

r3(config-router)#nei 2.2.12.13

r3(config-router)#end

Access-Server#2

[Resuming connection 2 to r2 ... ]

r2#sh ip rout

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

ia - IS-IS inter area, * - candidate default, U - per-user static route

o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

2.0.0.0/8 is variably subnetted, 3 subnets, 2 masks

C 2.2.2.2/32 is directly connected, Loopback0

C 2.2.12.0/24 is directly connected, Serial0/0

C 2.2.17.0/24 is directly connected, FastEthernet0/0

r2#

Access-Server#5

[Resuming connection 5 to R5 ... ]

*

r5#sh ip rout

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

ia - IS-IS inter area, * - candidate default, U - per-user static route

o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

2.0.0.0/8 is variably subnetted, 3 subnets, 2 masks

C 2.2.5.5/32 is directly connected, Loopback0

C 2.2.12.0/24 is directly connected, Serial0/0

C 2.2.17.0/24 is directly connected, FastEthernet0/1

150.2.0.0/24 is subnetted, 1 subnets

C 150.2.2.0 is directly connected, FastEthernet0/0

r5#

Access-Server#3

[Resuming connection 3 to R3 ... ]

// changing to "ip os ne p-mp" routes show up from other ospf areas

r3#conf t

Enter configuration commands, one per line. End with CNTL/Z.

r3(config)#router os 1

r3(config-router)#no nei 2.2.12.13

r3(config-router)#no nei 2.2.12.13

*Jun 16 17:45:02.901: %OSPF-5-ADJCHG: Process 1, Nbr 0.0.0.0 on Serial0/0.235 fr

om ATTEMPT to DOWN, Neighbor Down: Neighbor deconfigured

r3(config-router)#no nei 2.2.12.12

r3(config-router)#

*Jun 16 17:45:05.513: %OSPF-5-ADJCHG: Process 1, Nbr 0.0.0.0 on Serial0/0.235 fr

om ATTEMPT to DOWN, Neighbor Down: Neighbor deconfigured

r3(config-router)#int s0/0.235

r3(config-subif)#ip os ne p

r3(config-subif)#ip os ne point-to-m

r3(config-subif)#

Access-Server#2

[Resuming connection 2 to r2 ... ]

r2#conf t

Enter configuration commands, one per line. End with CNTL/Z.

r2(config)#int s0/0

r2(config-if)#ip os ne po

r2(config-if)#ip os ne point-to-m

r2(config-if)#

Access-Server#5

[Resuming connection 5 to R5 ... ]

r5#conf t

Enter configuration commands, one per line. End with CNTL/Z.

r5(config)#int s0/0

r5(config-if)#ip os ne po

r5(config-if)#ip os ne point-to-m

r5(config-if)#

*Feb 4 03:29:09.656: %OSPF-5-ADJCHG: Process 1, Nbr 3.3.3.3 on Serial0/0 from L

OADING to FULL, Loading Done

r5(config-if)#end

r5#sh ip rout

*Feb 4 03:29:14.488: %SYS-5-CONFIG_I: Configured from console by console

r5#sh ip rout

Codes: C - connected, S - static, R - ....

2.0.0.0/8 is variably subnetted, 12 subnets, 3 masks

O 2.2.12.12/32 [110/128] via 2.2.12.11, 00:00:01, Serial0/0

O IA 2.2.6.6/32 [110/66] via 2.2.12.11, 00:00:01, Serial0/0

C 2.2.5.5/32 is directly connected, Loopback0

O IA 2.2.4.4/32 [110/129] via 2.2.12.11, 00:00:01, Serial0/0

O 2.2.3.3/32 [110/65] via 2.2.12.11, 00:00:01, Serial0/0

O 2.2.2.2/32 [110/129] via 2.2.12.11, 00:00:01, Serial0/0

O IA 2.2.1.1/32 [110/130] via 2.2.12.11, 00:00:01, Serial0/0

O 2.2.12.11/32 [110/64] via 2.2.12.11, 00:00:02, Serial0/0

O IA 2.2.8.0/21 [110/65] via 2.2.12.11, 00:00:02, Serial0/0

C 2.2.12.0/24 is directly connected, Serial0/0

O IA 2.2.16.0/24 [110/128] via 2.2.12.11, 00:00:02, Serial0/0

C 2.2.17.0/24 is directly connected, FastEthernet0/1

150.2.0.0/24 is subnetted, 1 subnets

C 150.2.2.0 is directly connected, FastEthernet0/0

r5#

Access-Server#2

[Resuming connection 2 to r2 ... ]

*Mar

r2(config-if)#end

r2#sh ip

*Mar 14 07:11:07.698: %SYS-5-CONFIG_I: Configured from console by console

r2#sh ip rout

Codes: C - connected, S - static, R - ....

2.0.0.0/8 is variably subnetted, 12 subnets, 3 masks

O IA 2.2.6.6/32 [110/66] via 2.2.12.11, 00:00:08, Serial0/0

O 2.2.5.5/32 [110/129] via 2.2.12.11, 00:00:08, Serial0/0

O IA 2.2.4.4/32 [110/129] via 2.2.12.11, 00:00:08, Serial0/0

O 2.2.3.3/32 [110/65] via 2.2.12.11, 00:00:08, Serial0/0

C 2.2.2.2/32 is directly connected, Loopback0

O IA 2.2.1.1/32 [110/130] via 2.2.12.11, 00:00:08, Serial0/0

O 2.2.12.13/32 [110/128] via 2.2.12.11, 00:00:08, Serial0/0

O 2.2.12.11/32 [110/64] via 2.2.12.11, 00:00:09, Serial0/0

O IA 2.2.8.0/21 [110/65] via 2.2.12.11, 00:00:09, Serial0/0

C 2.2.12.0/24 is directly connected, Serial0/0

O IA 2.2.16.0/24 [110/128] via 2.2.12.11, 00:00:09, Serial0/0

C 2.2.17.0/24 is directly connected, FastEthernet0/0

r2#

Hello Dengming,

this is a subtle issue:

when the IP OSPF network type is different on the two sides of a link even if the OSPF neighborship says it is up the other router cannot install in its routing tables the routes received by the other router even if actually received during the loading phase.

the OSPF network type must match.

you can compare the network type using

sh ip ospf interface type x/y

Hope to help

Giuseppe

Additional to Giuseppe's comment on network type. They network type needs to be matched or compatible with each other, like

- point-to-point is compatible with point-to-multipoint, but you need to make sure the hello and dead intervals are match

- broadcast is compatible with non-broadcast, but you need to make sure the hello and dead intervals are match

HTH,

jerry

Thanks Giuseppe and Jerry.

But how to make nei work, as nei is required and no way to bypass.

// all Network Type NON_BROADCAST

r3(config-router)#nei 2.2.12.12

r3(config-router)#nei 2.2.12.13

r3(config-router)#end

r3#sh ip os int s0/0.235

Serial0/0.235 is up, line protocol is up

Internet Address 2.2.12.11/29, Area 0

Process ID 1, Router ID 3.3.3.3, Network Type NON_BROADCAST, Cost: 64

....

r2#sh ip os int s0/0

Serial0/0 is up, line protocol is up

Internet Address 2.2.12.12/24, Area 0

Process ID 1, Router ID 2.2.2.2, Network Type NON_BROADCAST, Cost: 64

Transmit Delay is 1 sec, State DROTHER, Priority 0

No designated router on this network

No backup designated router on this network

Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5

r5#sh ip os int s0/0

Serial0/0 is up, line protocol is up

Internet Address 2.2.12.13/24, Area 0

Process ID 1, Router ID 5.5.5.5, Network Type NON_BROADCAST, Cost: 64

Transmit Delay is 1 sec, State DROTHER, Priority 0

No designated router on this network

No backup designated router on this network

Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5

r5#sh ip os nei

r5#

r2#sh ip os nei

r2#

r3#sh ip os nei

Neighbor ID Pri State Dead Time Address Interface

N/A 0 ATTEMPT/DROTHER - 2.2.12.12 Serial0/0.235

N/A 0 ATTEMPT/DROTHER - 2.2.12.13 Serial0/0.235

2.2.7.7 1 FULL/BDR 00:00:34 2.2.13.7 FastEthernet0/

0

2.2.9.9 1 FULL/DR 00:00:32 2.2.13.9 FastEthernet0/

0

6.6.6.6 1 2WAY/DROTHER 00:00:37 2.2.13.1 FastEthernet0/

0

2.2.8.8 1 FULL/BDR 00:00:31 2.2.10.8 FastEthernet0/

1

4.4.4.4 0 FULL/ - 00:00:31 2.2.16.4 Serial0/1

r3#

Without seeing your configuration, I can't really tell what is wrong. However, I have tested the condition you've described, and I am able to get it to work, please see below:

! R3

interface Serial0/0

no ip address

encapsulation frame-relay

no frame-relay inverse-arp

!

interface Serial0/0.333 multipoint

ip address 152.1.123.3 255.255.255.0

frame-relay map ip 152.1.123.1 301

frame-relay map ip 152.1.123.2 302

!

router ospf 1

log-adjacency-changes

network 150.1.3.3 0.0.0.0 area 0

network 152.1.123.3 0.0.0.0 area 0

neighbor 152.1.123.1

neighbor 152.1.123.2

!

! R1

interface Serial0/0

ip address 152.1.123.1 255.255.255.0

encapsulation frame-relay

ip ospf priority 0

frame-relay map ip 152.1.123.3 103

frame-relay map ip 152.1.123.2 103 !<- next hop resolution for networks adv by R2

!

router ospf 1

log-adjacency-changes

network 150.1.1.1 0.0.0.0 area 0

network 152.1.123.1 0.0.0.0 area 0

!

! R2

interface Serial0/0

ip address 152.1.123.2 255.255.255.0

encapsulation frame-relay

ip ospf priority 0

frame-relay map ip 152.1.123.3 203

frame-relay map ip 152.1.123.1 203 !<- next hop resolution for networks adv by R1

no frame-relay inverse-arp

!

router ospf 1

log-adjacency-changes

network 150.1.2.2 0.0.0.0 area 0

network 152.1.123.2 0.0.0.0 area 0

!

Here is the show output

! R3

Rack1R3#sh frame map

Serial0/0.333 (up): ip 152.1.123.1 dlci 301(0x12D,0x48D0), static,

CISCO, status defined, active

Serial0/0.333 (up): ip 152.1.123.2 dlci 302(0x12E,0x48E0), static,

CISCO, status defined, active

Rack1R3#sh ip ospf nei

Neighbor ID Pri State Dead Time Address Interface

150.1.1.1 0 FULL/DROTHER 00:01:58 152.1.123.1 Serial0/0.333

150.1.2.2 0 FULL/DROTHER 00:01:34 152.1.123.2 Serial0/0.333

Rack1R3#sh ip ospf int s0/0.333

Serial0/0.333 is up, line protocol is up

Internet Address 152.1.123.3/24, Area 0

Process ID 1, Router ID 150.1.3.3, Network Type NON_BROADCAST, Cost: 64

Transmit Delay is 1 sec, State DR, Priority 1

Designated Router (ID) 150.1.3.3, Interface address 152.1.123.3

No backup designated router on this network

Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5

.....

Neighbor Count is 2, Adjacent neighbor count is 2

Adjacent with neighbor 150.1.1.1

Adjacent with neighbor 150.1.2.2

Suppress hello for 0 neighbor(s)

! R1

Rack1R1#sh frame map

Serial0/0 (up): ip 152.1.123.3 dlci 103(0x67,0x1870), static,

CISCO, status defined, active

Rack1R1#sh ip ospf nei

Neighbor ID Pri State Dead Time Address Interface

150.1.3.3 1 FULL/DR 00:01:32 152.1.123.3 Serial0/0

Rack1R1#sh ip ospf int s0/0

Serial0/0 is up, line protocol is up

Internet Address 152.1.123.1/24, Area 0

Process ID 1, Router ID 150.1.1.1, Network Type NON_BROADCAST, Cost: 64

Transmit Delay is 1 sec, State DROTHER, Priority 0

Designated Router (ID) 150.1.3.3, Interface address 152.1.123.3

No backup designated router on this network

Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5

! R2

Rack1R2#sh frame map

Serial0/0 (up): ip 152.1.123.3 dlci 203(0xCB,0x30B0), static,

CISCO, status defined, active

Rack1R2#sh ip ospf nei

Neighbor ID Pri State Dead Time Address Interface

150.1.3.3 1 FULL/DR 00:01:30 152.1.123.3 Serial0/0

Rack1R2#sh ip ospf int s0/0

Serial0/0 is up, line protocol is up

Internet Address 152.1.123.2/24, Area 0

Process ID 1, Router ID 150.1.2.2, Network Type NON_BROADCAST, Cost: 64

Transmit Delay is 1 sec, State DROTHER, Priority 0

Designated Router (ID) 150.1.3.3, Interface address 152.1.123.3

No backup designated router on this network

Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5

Regards,

jerry

wow. thanks Jerry for your great effort to the help.

I do extra test again for another lab: the hub s0/0.134 mul to r3, r4 spoke s0/0 nei statement with same thing r3, or r4 no route from ospf other areas.

No worry. I will see if I will put together all the config files for your check later on.

Thanks again Jerry and All for the great help and have a wonderful day.

It is lucky to get it working tonight.

Thanks Jerry. I am good. I will keep watch on this and will update this as needed.

R5#

interface Serial0/0

no ip address

encapsulation frame-relay

no frame-relay inverse-arp

frame-relay lmi-type cisco

!

interface Serial0/0.125 multipoint

ip address 2.2.125.5 255.255.255.0

ip ospf priority 255

snmp trap link-status

frame-relay map ip 2.2.125.1 501 broadcast

frame-relay map ip 2.2.125.2 502 broadcast

frame-relay map ip 2.2.125.5 501

!

router ospf 1

log-adjacency-changes

network 2.2.5.5 0.0.0.0 area 0

network 2.2.125.5 0.0.0.0 area 0

neighbor 2.2.125.1

neighbor 2.2.125.2

R1#

interface Serial0/0

ip address 2.2.125.1 255.255.255.0

encapsulation frame-relay

ip ospf priority 0

no dce-terminal-timing-enable

frame-relay map ip 2.2.125.1 105

frame-relay map ip 2.2.125.2 105 broadcast

frame-relay map ip 2.2.125.5 105 broadcast

no frame-relay inverse-arp

frame-relay lmi-type cisco

!

interface Serial0/1

ip address 2.2.13.1 255.255.255.0

encapsulation frame-relay

ip ospf network point-to-point

no dce-terminal-timing-enable

frame-relay map ip 2.2.13.1 113

frame-relay map ip 2.2.13.3 113 broadcast

no frame-relay inverse-arp

!

router ospf 1

log-adjacency-changes

network 2.2.1.1 0.0.0.0 area 0

network 2.2.13.1 0.0.0.0 area 13

network 2.2.125.1 0.0.0.0 area 0

R2#

interface Serial0/0

ip address 2.2.125.2 255.255.255.0

encapsulation frame-relay

ip ospf priority 0

frame-relay map ip 2.2.125.1 205 broadcast

frame-relay map ip 2.2.125.2 205

frame-relay map ip 2.2.125.5 205 broadcast

no frame-relay inverse-arp

frame-relay lmi-type cisco

!

router ospf 1

log-adjacency-changes

network 2.2.2.2 0.0.0.0 area 0

network 2.2.125.2 0.0.0.0 area 0

!

================

r5#sh ip os nei

Neighbor ID Pri State Dead Time Address Interface

2.2.1.1 0 FULL/DROTHER 00:01:57 2.2.125.1 Serial0/0.125

2.2.2.2 0 FULL/DROTHER 00:01:59 2.2.125.2 Serial0/0.125

r1#sh ip os nei

Neighbor ID Pri State Dead Time Address Interface

2.2.5.5 255 FULL/DR 00:01:55 2.2.125.5 Serial0/0

2.2.3.3 0 FULL/ - 00:00:30 2.2.13.3 Serial0/1

r2#sh ip os nei

Neighbor ID Pri State Dead Time Address Interface

2.2.5.5 255 FULL/DR 00:01:50 2.2.125.5 Serial0/0

r2#sh ip rou

2.0.0.0/8 is variably subnetted, 11 subnets, 2 masks

O IA 2.2.7.7/32 [110/130] via 2.2.125.1, 00:00:24, Serial0/0

O 2.2.5.5/32 [110/65] via 2.2.125.5, 00:01:58, Serial0/0

O IA 2.2.3.3/32 [110/129] via 2.2.125.1, 00:00:34, Serial0/0

C 2.2.2.2/32 is directly connected, Loopback0

O 2.2.1.1/32 [110/65] via 2.2.125.1, 00:01:58, Serial0/0

O IA 2.2.12.0/24 [110/129] via 2.2.125.1, 00:00:19, Serial0/0

O IA 2.2.13.0/24 [110/128] via 2.2.125.1, 00:01:58, Serial0/0

r1#sh ip rout

2.0.0.0/8 is variably subnetted, 8 subnets, 2 masks

O 2.2.7.7/32 [110/66] via 2.2.13.3, 00:00:30, Serial0/1

O 2.2.5.5/32 [110/65] via 2.2.125.5, 00:01:41, Serial0/0

O 2.2.3.3/32 [110/65] via 2.2.13.3, 00:00:30, Serial0/1

O 2.2.2.2/32 [110/65] via 2.2.125.2, 00:01:41, Serial0/0

C 2.2.1.1/32 is directly connected, Loopback0

O 2.2.12.0/24 [110/65] via 2.2.13.3, 00:00:30, Serial0/1

r5#sh ip rout

2.0.0.0/8 is variably subnetted, 10 subnets, 2 masks

O IA 2.2.7.7/32 [110/130] via 2.2.125.1, 00:00:37, Serial0/0.125

C 2.2.5.5/32 is directly connected, Loopback0

O IA 2.2.3.3/32 [110/129] via 2.2.125.1, 00:00:47, Serial0/0.125

O 2.2.2.2/32 [110/65] via 2.2.125.2, 00:02:11, Serial0/0.125

O 2.2.1.1/32 [110/65] via 2.2.125.1, 00:02:11, Serial0/0.125

O IA 2.2.12.0/24 [110/129] via 2.2.125.1, 00:00:32, Serial0/0.125

O IA 2.2.13.0/24 [110/128] via 2.2.125.1, 00:02:11, Serial0/0.125

Okay, thanks for letting me know.

Regards,

jerry

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