Frame-relay Problems

[david foley]

Hi have a Hub & Spoke Frame Relay set up, R4 - R5 & R4 - R6 are all pinging ok, But if i go R5 - R6 or R6 - R5 they are not pinging each other,

I cant get the PC which on R5 to ping R4 nor the Server on R6. I set up OSPF 1 for the Frame Links to see would this fix the problem. but with no joy. could some one tell me where i am going wrong in how i fix this problem so All Routers within Frame Relay can ping.

R4

Building configuration...

Current configuration : 951 bytes
!
version 12.4
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname R4
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface FastEthernet0/0
no ip address
duplex auto
speed auto
shutdown
!
interface FastEthernet0/1
no ip address
duplex auto
speed auto
shutdown
!
interface Serial0/0/0
ip address 172.190.0.6 255.255.255.252
!
interface Serial0/0/1
ip address 172.190.0.18 255.255.255.252
encapsulation frame-relay
frame-relay map ip 172.190.0.17 405 broadcast
frame-relay map ip 172.190.0.18 405
!
interface Serial0/0/1.406 point-to-point
ip address 172.190.0.22 255.255.255.252
frame-relay interface-dlci 406
!
interface Vlan1
no ip address
shutdown
!
router ospf 1
log-adjacency-changes
network 172.190.0.4 0.0.0.3 area 0
network 172.190.0.20 0.0.0.3 area 0
network 172.190.0.16 0.0.0.3 area 0
!
ip classless
!
!
!
!
!
!
!
line con 0
line vty 0 4
login
!
!
!
end

R5

hostname Router
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface FastEthernet0/0
ip address 172.190.0.81 255.255.255.248
duplex auto
speed auto
!
interface FastEthernet0/1
no ip address
duplex auto
speed auto
shutdown
!
interface Serial0/0/0
no ip address
shutdown
!
interface Serial0/0/1
ip address 172.190.0.17 255.255.255.252
encapsulation frame-relay
frame-relay map ip 172.190.0.18 504 broadcast
frame-relay map ip 172.190.0.17 504
!
interface Vlan1
no ip address
shutdown
!
router ospf 1
log-adjacency-changes
network 172.190.0.16 0.0.0.3 area 0
network 172.190.0.0 0.0.0.255 area 0
!
ip classless
!
!
!
!
!
!
!
line con 0
line vty 0 4
login
!
!
!
end

R6

Building configuration...

Current configuration : 805 bytes
!
version 12.4
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Router
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface FastEthernet0/0
ip address 172.190.0.73 255.255.255.248
duplex auto
speed auto
!
interface FastEthernet0/1
no ip address
duplex auto
speed auto
shutdown
!
interface Serial0/0/0
ip address 172.190.0.21 255.255.255.252
encapsulation frame-relay
frame-relay map ip 172.190.0.22 604 broadcast
frame-relay map ip 172.190.0.21 604
!
interface Serial0/0/1
no ip address
shutdown
!
interface Vlan1
no ip address
shutdown
!
router ospf 1
log-adjacency-changes
network 172.190.0.20 0.0.0.3 area 0
network 172.190.0.0 0.0.0.255 area 0
!
ip classless
!
!
!
!
!
!
!
line con 0
line vty 0 4
login
!
!
!
end

[Kasiraman S]

Hi David,

Please provide the "show ip route ospf" from both spoke routers. Most probably this could be an issue with encapsulation.

Thanks,

Kasi

[david foley]

R5

Router#show ip route ospf

Router#show ip route

Codes: C - connected, S - static, I - IGRP, 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, E - EGP

       i - IS-IS, 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

     172.190.0.0/16 is variably subnetted, 2 subnets, 2 masks

C       172.190.0.16/30 is directly connected, Serial0/0/1

C       172.190.0.80/29 is directly connected, FastEthernet0/0

Router#show ip ospf

Routing Process "ospf 1" with ID 172.190.0.81

Supports only single TOS(TOS0) routes

Supports opaque LSA

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 0x000000

Number of opaque AS LSA 0. Checksum Sum 0x000000

Number of DCbitless external and opaque AS LSA 0

Number of DoNotAge external and opaque AS LSA 0

Number of areas in this router is 1. 1 normal 0 stub 0 nssa

External flood list length 0

    Area BACKBONE(0)

        Number of interfaces in this area is 2

        Area has no authentication

        SPF algorithm executed 1 times

        Area ranges are

        Number of LSA 1. Checksum Sum 0x005506

        Number of opaque link LSA 0. Checksum Sum 0x000000

        Number of DCbitless LSA 0

        Number of indication LSA 0

        Number of DoNotAge LSA 0

        Flood list length 0

Router#show ip ospf

Routing Process "ospf 1" with ID 172.190.0.81

Supports only single TOS(TOS0) routes

Supports opaque LSA

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 0x000000

Number of opaque AS LSA 0. Checksum Sum 0x000000

Number of DCbitless external and opaque AS LSA 0

Number of DoNotAge external and opaque AS LSA 0

Number of areas in this router is 1. 1 normal 0 stub 0 nssa

External flood list length 0

    Area BACKBONE(0)

        Number of interfaces in this area is 2

        Area has no authentication

        SPF algorithm executed 1 times

        Area ranges are

        Number of LSA 1. Checksum Sum 0x005506

        Number of opaque link LSA 0. Checksum Sum 0x000000

        Number of DCbitless LSA 0

        Number of indication LSA 0

        Number of DoNotAge LSA 0

        Flood list length 0

R6

Router#show ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
       i - IS-IS, 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

     172.190.0.0/16 is variably subnetted, 2 subnets, 2 masks
C       172.190.0.20/30 is directly connected, Serial0/0/0
C       172.190.0.72/29 is directly connected, FastEthernet0/0
Router#

when i do a show run

ospf not happens..

but i did do a Router ospf 1

network 172.190.0.20
0.0.0.3 area 0 on that router.

i done it their now again.

[Kasiraman S]

Hello David,

issue the show ip ospf nei and you cant see any adj, its because of its frame-relay interface type.

1) Frame Relay physical interface is a multipoint interface type by default, OSPF treats it as a non-broadcast network type. Even though you have broadcast keyword on the frame-relay map it would not work, because physical inteface does not carry broadcast because of it nature. On the R4 side we have Point-to-point subinterface and only possibly have two devices on it, broadcasts are supported.  OSPF  treats it as a point-to-point network type

You can overcom this by enabling "ip ospf network broadcast" on the physical interface to solve the broadcast issue or can form the neighbor relationship by adding neighbor statement.

-----> go to R6 serial interface and add the command "ip ospf network broadcast"

R6

inter se X

ip ospf network broadcast

2) Between R4 and R5 we are running frame-relay in the physical interface, so it by default does not broadcast. So add the same command on the both the side to form adj.

R4:

inter se X

ip ospf network broadcast

R5

inter se X

ip ospf network broadcast

try and let me know if this helps.

Thanks,

Kasi

[cadet alain]

Hi,

So I've relabbed your topology but replacing no Frame-relay with Loopbacks
and the Serial numbering is different.
Here's what is happening:

r4(config-router)#do sh ip os in br
Interface    PID   Area            IP Address/Mask    Cost  State Nbrs F/C
Se0/0        1     0               172.190.0.18/30    64    DR    0/0
Se0/0.406    1     0               172.190.0.22/30    64    P2P   0/0
Lo0          1     0               172.190.0.6/30     1     LOOP  0/0

r5:

r5# sh ip os in b
Interface    PID   Area            IP Address/Mask    Cost  State Nbrs F/C
Lo0          1     0               172.190.0.81/29    1     LOOP  0/0
Se0/0        1     0               172.190.0.17/30    64    DR    0/0

r6:

r6(config-router)#do sh ip os in b
Interface    PID   Area            IP Address/Mask    Cost  State Nbrs F/C
Lo0          1     0               172.190.0.73/29    1     LOOP  0/0
Se0/0        1     0               172.190.0.21/30    64    DR    0/0

As you can see you have ospf enabled on all your interfaces but between

r4-r5 where you have a physical interface( multipoint non broadcast), each

router thinks he is the DR.

So 1st you must tell R5 he will never be a DR with the interface command
ip ospf priority 0 then you will see this

r5(config-if)#do sh ip os in br
Interface    PID   Area            IP Address/Mask    Cost  State Nbrs F/C
Lo0          1     0               172.190.0.81/29    1     LOOP  0/0
Se0/0        1     0               172.190.0.17/30    64    DROTH 0/0

But Still you've got no ospf adjacency on any router.
For R4-R5 as it is NBMA network you must use the neighbor command under the ospf process on R4:

r4(config-router)#router os 1
r4(config-router)#neighbor 172.190.0.17

and then on R4 you'll see
r4(config-router)#do sh ip os nei

Neighbor ID     Pri   State           Dead Time   Address         Interface
172.190.0.81      0   FULL/DROTHER    00:01:56    172.190.0.17    Serial0/0

and on R5:
r5(config-if)#do sh ip os nei

Neighbor ID     Pri   State           Dead Time   Address         Interface
172.190.0.6       1   FULL/DR         00:01:50    172.190.0.18    Serial0/0

Now you still have a problem between R4 and R6
if you do a sh ip os int s0/0.406 on R4 you'll see

r4(config-router)#do sh ip os int s0/0.406
Serial0/0.406 is up, line protocol is up
  Internet Address 172.190.0.22/30, Area 0
  Process ID 1, Router ID 172.190.0.6, Network Type POINT_TO_POINT,

Cost: 64
  Transmit Delay is 1 sec, State POINT_TO_POINT
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

And the same on R6 s0/0

r6(config)#do sh ip os int s0/0
Serial0/0 is up, line protocol is up
  Internet Address 172.190.0.21/30, Area 0
  Process ID 1, Router ID 172.190.0.73, Network Type NON_BROADCAST,

Cost: 64
  Transmit Delay is 1 sec, State DR, Priority 1
  Designated Router (ID) 172.190.0.73, Interface address 172.190.0.21
  No backup designated router on this network
  Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5

You have different ospf network types with different timers but also a different view of the network.
On R4 we have point-to-point so no DR/BDR,broadcast and on R6 we have NBMA so DR/BDR, no broadcast.
We could modify the timers so they are equal on both sides and there would be an adjacency

but as the LSA database would be inconsistent then  you wouldn't see routes installed in the RIB.
So the solution is to change the ospf network type of R6 to point-to-point with the interface command ip os netw point-to-p

r6(config-if)#ip os netw point-to-p
r6(config-if)#
*Mar  1 00:43:29.035: %OSPF-5-ADJCHG: Process 1, Nbr 172.190.0.6 on

Serial0/0 from LOADING to FULL, Loading Done
r6(config-if)#do sh ip os nei

Neighbor ID     Pri   State           Dead Time   Address         Interface
172.190.0.6       0   FULL/  -        00:00:33    172.190.0.22    Serial0/0

r4(config-router)#do sh ip os nei

Neighbor ID     Pri   State           Dead Time   Address         Interface
172.190.0.81      0   FULL/DROTHER    00:01:59    172.190.0.17    Serial0/0
172.190.0.73      0   FULL/  -        00:00:34    172.190.0.21            Serial0/0.406

so on R5

r5(config-if)#do sh ip ro os
     172.190.0.0/16 is variably subnetted, 5 subnets, 3 masks
O       172.190.0.20/30 [110/128] via 172.190.0.18, 00:12:15, Serial0/0
O       172.190.0.6/32 [110/65] via 172.190.0.18, 00:12:15, Serial0/0
O       172.190.0.73/32 [110/129] via 172.190.0.18, 00:00:51, Serial0/0

on R6

r6(config-if)#do sh ip ro os
     172.190.0.0/16 is variably subnetted, 5 subnets, 3 masks
O       172.190.0.16/30 [110/128] via 172.190.0.22, 00:01:58, Serial0/0
O       172.190.0.6/32 [110/65] via 172.190.0.22, 00:01:58, Serial0/0
O       172.190.0.81/32 [110/129] via 172.190.0.22, 00:01:58, Serial0/0

And You have full connectivity from end to end.

Regards.

Alain.

[Kasiraman S]

Hi Alain,

Thanks. got it. We can also have dynamic discovery between between R4 and R5 by adding ip ospf network broadcast right? Will that work?

Secondly, As per your coment it seems like network type should match between the neighbor. Eventhough they form neighbor but they do not put the routes in the RIB, because of the unmatched network type??

Thanks,

Kasi

[cadet alain]

Hi,

We can also have dynamic discovery between between R4 and R5 by adding ip ospf network broadcast right? Will that work?

Yes it will work if you don't want to use the neighbour command but it will change the timers to 10 and 40 instead of 30 120.

Secondly, As per your coment it seems like network type should match 
between the neighbor. Eventhough they form neighbor but they do not put 
the routes in the RIB, because of the unmatched network type??

To form a neighbourship, there is nothing told about network types but the timers must be the same(hello and dead timers).

So I could change the timers on one side to fit the other side and the neighbour ship would come up.

But as the network types are incompatible  the routers won't put the routes in their routing table.

here is what it will look like

r6(config-if)#ip ospf hello-interval 10
r6(config-if)#do sh ip os in s0/0
Serial0/0 is up, line protocol is up
  Internet Address 172.190.0.21/30, Area 0
  Process ID 1, Router ID 172.190.0.73, Network Type NON_BROADCAST, Cost: 64
  Transmit Delay is 1 sec, State WAITING, Priority 1
  No designated router on this network
  No backup designated router on this network
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
    Hello due in 00:00:04
    Wait time before Designated router selection 00:01:04
  Supports Link-local Signaling (LLS)
  Cisco NSF helper support enabled
  IETF NSF helper support enabled
  Index 1/1, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 1, maximum is 1
  Last flood scan time is 0 msec, maximum is 0 msec
  Neighbor Count is 1, Adjacent neighbor count is 0
  Suppress hello for 0 neighbor(s)
r6(config-if)#
r6(config-if)#
r6(config-if)#
r6(config-if)#
r6(config-if)#do sh ip os nei

Neighbor ID     Pri   State           Dead Time   Address         Interface
172.190.0.6       1   2WAY/DROTHER    00:00:38    172.190.0.22    Serial0/0
r6(config-if)#
*Mar  1 01:49:18.031: %OSPF-5-ADJCHG: Process 1, Nbr 172.190.0.6 on Serial0/0 from LOADING to FULL, Loading Done
r6(config-if)#do sh ip os nei

Neighbor ID     Pri   State           Dead Time   Address         Interface
172.190.0.6       1   FULL/BDR        00:00:32    172.190.0.22    Serial0/0
r6(config-if)#do sh ip ro os

r4(config-router)#do sh ip os nei

Neighbor ID     Pri   State           Dead Time   Address         Interface
172.190.0.81      0   FULL/DROTHER    00:01:57    172.190.0.17    Serial0/0
172.190.0.73      0   FULL/  -        00:00:37    172.190.0.21    Serial0/0.406
r4(config-router)#do sh ip ro os
     172.190.0.0/16 is variably subnetted, 4 subnets, 2 masks
O       172.190.0.81/32 [110/65] via 172.190.0.17, 00:04:44, Serial0/0

Regards.

Alain.

[david foley]

HI Cadetalain / kasiva

Once i get home from work, i will Try out this command

inter se X

ip ospf network broadcast

I dont want to mess around to much with the loopback 0 as ill have to change all the VLSM,

int s0/0/1

ip opsf network broadcast.

will that force all Ospf to dynamic ? for this to work on the Sub int will i need to change point-to-point to something else ?

but this command should allow my Routers to ping one another inc the host on R5 - R6

regards,

Dave

[cadet alain]

Hi,

will that force all Ospf to dynamic ? for this to work on the Sub int will i need to change point-to-point to something else ?

but this command should allow my Routers to ping one another inc the host on R5 - R6

Setting the ospf network type to broadcast will make the neighbourship come up without using the neighbor command which is mandatory on a

NBMA network( which is the default for a FR physical interface).

But don't forget you have a hub and spoke topology so the hub must be the DR and the spokes must be DROTHERS and to achieve this ,

on the spokes issue interface following command: ip ospf priority 0.

For the R4-R6 adjacency, there was a network type mismatch: NBMA vs point-to-point so here simplest for me is to change the network type

of R6 physical interface from NBMA(default) to point-to-point.

When both adjacencies are full then you will have all your ospf routes and your ping will work.

Regards.

Alain.

[david foley]

OK, i done all that and R5 is working and its host PC is working away, but R6 still can't ping try changing the Point-to-point to multipoint but gives an error on R4.

I would say point-to-point is blocking the Server from getting out of R6 to R4,

to getting a better image i have upload my PT file.

regards

Dave

[cadet alain]

Hi,

Can you upload as jpeg or pdf or doc, thks.

And also  sh ip os nei on r6, sh ip os in br on r6

Regards.

alain.

[david foley]

Router#show ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
172.190.0.22      0   2WAY/DROTHER    00:00:33    172.190.0.22    Serial0/0/0
Router#

Router#show ip ospf in serial0/0/0
Serial0/0/0 is up, line protocol is up
  Internet address is 172.190.0.21/30, Area 0
  Process ID 1, Router ID 172.190.0.73, Network Type BROADCAST, Cost: 64
  Transmit Delay is 1 sec, State WAITING, Priority 0
  No designated router on this network
  No backup designated router on this network
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    Hello due in 00:00:09
  Index 2/2, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 1, maximum is 1
  Last flood scan time is 0 msec, maximum is 0 msec
  Neighbor Count is 1, Adjacent neighbor count is 0
  Suppress hello for 0 neighbor(s

Router#show ip ospf database
            OSPF Router with ID (172.190.0.73) (Process ID 1)

                Router Link States (Area 0)

Link ID         ADV Router      Age         Seq#       Checksum Link count
172.190.0.73    172.190.0.73    280         0x80000003 0x00dd91 2
Router#
Router#show ip ospf database
            OSPF Router with ID (172.190.0.73) (Process ID 1)

                Router Link States (Area 0)

Link ID         ADV Router      Age         Seq#       Checksum Link count
172.190.0.73    172.190.0.73    293         0x80000003 0x00dd91 2
Router#

[cadet alain]

Hi,

So you put tne network type of broadcast on both R6 s0/0/0 and R4 s0/0/0.406 but when you did the sh ip ospf nei the adjacency was not full because on frame-relay it takes sometimes to come up. Can you do sh ip os nei  a little bit later on both routers as well as sh ip ospf and sh ip os in s0/0/0.406 on R4

Regards.

Alain.

[david foley]

hi,

my last message never show up for some reason,,

SO  i did what you told me leave PT on for a while i left it on for about 16mins and still now luck,

The same Config that i posted in my last Message was the Same output when i left it run for 16mins

Not a home so cant  post the Config..

But it still on State WAITING, Priority 0 this could be the problem that its not going from WAITING to Point-to-Point

[cadet alain]

Hi,

Priority 0 means the router will never be DR/BDR on this segment but it's no use if the ospf network type is point-to-point

as there is no DR/BDR election in this case.

When I said it can take some time you don't need to wait for this long, remember the highest dead interval is 120 seconds.

If the adjacency doesn't get full then most probably there is a timer mismatch due to different ospf network type timers on both end.

when you get home post the packet tracer topology.

Regards.

Alain.