Re: ospf routing path

bmehdi · ‎09-30-2003

Hi ,

we have three router connected to each other via frame-relay.My router is connected to the other two via frame-relay.problem is all the routes my router learns (of both router ) is from serial 1/0.1.

----------------------------------------------

int serial1/0.1 point-to-point

ip address 10.1.1.253 255.255.255.252

int serial1/0.1 point-to-point

ip address 10.1.1.249 255.255.255.252

ospf configuration is

router ospf 10

network 10.2.1.1 0.0.0.255 area 20(my router network)

network 10.1.1.240 0.0.0.15 area 0

show ip ospf neighbor identifies both the neighboirs in full state.

Any suggestions

deilert · ‎09-30-2003

according to above you have 2 s1/0.1 interfaces . For some reason it sees this as a more attractive router , are you using the ip ospf cost command or are you setting a bandwidth statement on the interfaces, Can you paste in a sh run

ruwhite · ‎09-30-2003

This can't be your configuration--as David has noted, you have tow s0/0.1's... If you typed this in this way, it would just change the ip address on the one subinterface. :-)

I don't see where you're tying the frame dlci's to the subinterfaces--maybe the router has both frame dlci's on one subinterface, or on the main interface (?). And, are you seeing this on the "hub" of the frame cloud, or the "spokes" of the frame cloud (just to make certain I understand your question correctly).

Russ.W

bmehdi · ‎09-30-2003

thanks for the response and sorry ,typo here ,actually the other serial subinterface is serial 1/0.2.And two PVC by dlci's are defined for each of the interfaces.

wanted to add another thing and that is the other two routers are learning routes from the routers attached to them.This is confusing,Any commands or hints ?

ruwhite · ‎09-30-2003

I hate to ask more questions, but.... Are you saying that both of the "spoke" routers are learning all their routes only through the "hub" router on the frame cloud? If so, that would be natural, really, since there's no PVC between the "spoke" routers directly.

Is this what you are seeing, or are the routes not learned on the "hub" router?

Russ.W

bmehdi · ‎09-30-2003

Np,questions are welcome,following is the flow maybe it will help

ROuterA --pvc--RouterB--pvc-routerC

| |

----------pvc--------------

My router is RouterB ,my router is learning routes of router A and C from router C.While router A is learning my routes from me,and router C's routes from C.Same is the case with router C.

Does this make sence.

ipotts · ‎09-30-2003

It could be that the cost of the pvc B-C is lower than the cost of B-A-C. Please send the output of the sh ip ospf interface for all 6 PVC interfaces,

Regards

Ian

bmehdi · ‎10-01-2003

router A and C are also connected and have a pvc.

following is the show ip ospf and show ip neighbor output at my router

sh ip ospf

Routing Process "ospf 20" with ID 10.20.1.1 and Domain ID 0.0.0.20

Supports only single TOS(TOS0) routes

Supports opaque LSA

It is an area border router

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 0. Checksum Sum 0x0

Number of opaque AS LSA 0. Checksum Sum 0x0

-------------------------------------------

MSCLHR#sh ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

10.21.1.1 1 FULL/ - 00:00:32 10.1.254.250 Serial1/0.2

10.22.1.1 1 FULL/ - 00:00:34 10.1.254.254 Serial1/0.1

my router shows routes learned by 10.1.254.254 only via serial 1/0.1

bmehdi · ‎10-01-2003

router A and C are also connected and have a pvc.

following is the show ip ospf and show ip neighbor output at my router

sh ip ospf

Routing Process "ospf 20" with ID 10.20.1.1 and Domain ID 0.0.0.20

Supports only single TOS(TOS0) routes

Supports opaque LSA

It is an area border router

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 0. Checksum Sum 0x0

Number of opaque AS LSA 0. Checksum Sum 0x0

-------------------------------------------

MSCLHR#sh ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

10.21.1.1 1 FULL/ - 00:00:32 10.1.254.250 Serial1/0.2

10.22.1.1 1 FULL/ - 00:00:34 10.1.254.254 Serial1/0.1

my router shows routes learned by 10.1.254.254 only via serial 1/0.1

bmehdi · ‎10-01-2003

at my router.

sh ip ospf interface s1/0.1

Serial1/0.1 is up, line protocol is up

Internet Address 10.1.254.253/30, Area 0

Process ID 20, Router ID 10.22.1.1, Network Type POINT_TO_POINT, Cost: 48

Transmit Delay is 1 sec, State POINT_TO_POINT,

Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

Hello due in 00:00:07

Index 1/1, flood queue length 0

MSCLHR#sh ip ospf int s1/0.2

Serial1/0.2 is up, line protocol is up

Internet Address 10.1.254.249/30, Area 0

Process ID 20, Router ID 10.21.1.1, Network Type POINT_TO_POINT, Cost: 48

Transmit Delay is 1 sec, State POINT_TO_POINT,

Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

Hello due in 00:00:07

Index 2/2, flood qu

ruwhite · ‎10-01-2003

Could you do a:

show ip ospf data router 10.21.1.1

? That would tell us what the local router has received from this neighbor on its router LSA. If you know of some route which is attached to 10.21.1.1, could you capture a show ip route for that route?

Russ.W

bmehdi · ‎10-01-2003

here are the outputs,my router id is 10.23.1.1,as you can see the 10.21.1.1 is learning routes from both routers while my ip route learn just from 10.22.1.1

sh ip ospf database

OSPF Router with ID (10.21.1.1) (Process ID 30)

Router Link States (Area 0)

Link ID ADV Router Age Seq# Checksum Link count

10.21.1.1 10.21.1.1 128 0x8000060D 0x5D51 4

10.22.1.1 10.22.1.1 127 0x80000734 0xF9CD 4

10.23.1.1 10.23.1.1 158 0x8000011F 0xCC0D 4

Summary Net Link States (Area 0)

Link ID ADV Router Age Seq# Checksum

10.22.0.0 10.22.1.1 636 0x80002DA1 0x5D38

10.21.1.0 10.21.1.1 159 0x8000009C 0xCFF4

10.21.2.0 10.21.1.1 159 0x8000061A 0xA36B

10.23.1.0 10.23.1.1 1346 0x80000101 0xEF6D

10.23.2.0 10.23.1.1 1346 0x80000101 0xD05A

Summary ASB Link States (Area 0)

Link ID ADV Router Age Seq# Checksum

10.21.11.1 10.21.1.1 175 0x8000061A 0x6A3C

Router Link States (Area 30)

Link ID ADV Router Age Seq# Checksum Link count

10.21.1.1 10.21.1.1 190 0x80000C1F 0x4F8E 18

10.21.11.1 10.21.11.1 336 0x8000583F 0x38A3 5

Summary Net Link States (Area 30)

Link ID ADV Router Age Seq# Checksum

10.22.0.0 10.21.1.1 141 0x80000002 0xE916

10.22.254.244 10.21.1.1 135 0x80000003 0x45C9

10.22.254.248 10.21.1.1 181 0x80000001 0x6C7F

10.22.254.252 10.22.1.1 135 0x80000003 0x774F

10.23.1.0 10.21.1.1 161 0x80000001 0x14C8

sh ip route

Gateway of last resort is 10.21.254.246 to network 0.0.0.0

10.21.0.0/24 is subnetted, 19 subnets

C 10.21.191.0 is directly connected, Serial

C 10.21.190.0 is directly connected, Serial

10.22.0.0/16 is variably subnetted, 4 subnets, 2 masks

C 10.22.254.244/30 is directly connected, Serial3/1.1

C 10.22.254.248/30 is directly connected, Serial3/1.2

O IA 10.22.0.0/16 [110/98] via 10.22.254.246, 00:03:10, Serial3/1.1

O 10.22.254.252/30 [110/161] via 10.22.254.246, 00:03:10, Serial3/1.1

10.23.0.0/24 is subnetted, 15 subnets

O IA 10.23.158.0 [110/237] via 10.23.254.249, 00:03:10, Serial3/1.2

O IA 10.18.159.0 [110/181] via 10.23.254.249, 00:03:10, Serial3/1.2

ipotts · ‎10-01-2003

According to your sh ip rou you are getting routes from s3/1.1 and 1.2 so I don't see the problem you described of getting routes from only one neighbor. Would you please help me understand this?

bmehdi · ‎10-01-2003

This output is of the other router thats getting the information as it should .

mine is not.

ruwhite · ‎10-01-2003

Okay, so could you post the output of show ip ospf data router 10.21.1.1 and show ip ospf data router 10.22.1.1 from your router? I don't see the actual database from your router anyplace on the thread (?).

Thanks!

Russ.W