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Frame-Relay cannot receive advertisement

paulo.prista
Level 1
Level 1

Dear Friends,

I have a frame-relay small network with a star topology. Core router is a 3640 and 7 branches use 1750.

Core router has 7 subinterfaces point-to-point configured in one an interface.

5 branches have subinterfaces in their interface and 2 use the interface without explicit subinterface.

Routing alghorithm is RIP 2, no special configuration is in place, mostly use default, including the reverse ARP.

The problem is: core router is not receiving branches routers advertisements. But each branch receives advertisements from core router.

I posted this question before, receiving two advices. First was "use broadcast option" and second "neighbor option".

I tried both but things did not change.

I would like to get some help for this.

Thanks, Paulo

30 Replies 30

Harold Ritter
Cisco Employee
Cisco Employee

Paulo,

Could you include the config of one of the remote sites.

Thanks,

Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México

Ok. It is one sample config, from branch router:

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

!

version 12.1

service timestamps debug uptime

service timestamps log uptime

service password-encryption

!

hostname XXX-XX-ROT-002

!

no logging console

enable secret xxxxxxxx

enable password xxxxx

!

memory-size iomem 25

ip subnet-zero

no ip finger

no ip domain-lookup

!

interface Serial0

description Link para Concentrador

no ip address

encapsulation frame-relay ietf

frame-relay lmi-type ansi

!

interface serial0.1 point-to-point

ip address 192.168.110.2 255.255.255.252

frame-relay interface-dlci 16

no ip directed-broadcast

no cdp enable

no fair-queue

!

interface FastEthernet0

ip address 192.168.10.1 255.255.255.0

speed auto

!

router rip

version 2

network 192.168.10.0

network 192.168.110.0

no auto-summary

!

ip classless

no ip http server

!

line con 0

exec-timeout 0 0

password xxxx

login

transport input none line aux 0

password xxxxx

login

line vty 0 4

password xxxx

login

!

end

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

Paulo

Is the hub configured as point-to-point subinterfaces, or as a single multipoint interface? It should be configured as a set of point-to-point subinterfaces, the way you have your remotes configured.

Russ.W

The hub has 7 sub-interfaces as point-to-point.

All data is flowing correctly, except Rip advertisements from branches to HQ.

Paulo

Can you ping 224.0.0.9? If the remotes respond, then there's a problem on the RIP side, most likely. If they don't, then multicast isn't working.

Russ.W

mark-obrien
Level 4
Level 4

Paulo,

Can the core router ping the branch routers over frame relay, and vice versa?

Mark

Yes, as I put static routes on the core, to circumvent this problem, everything is ok.

I can ping, data flows, all the system is working.

The only thing is that I cannot receive branches routers advertisements on the core.

In the past, we had this network running, in the same topology, with dedicated lines and Rip v2. At that time everything was ok. As we changed to frame-relay, we observed that the core stopped receiving branches routes.

Paulo

Hello Paulo,

I am not sure what the config of your hub router looks like, but you might want to check if split-horizon is disabled. Try to explicitly disable it with no ip split-horizon command.

Regards,

Georg

split horizon would only prevent the hub from propagating the updates from one spoke to another.

Can we have a "sh ip prot" on one of the spokes and the hub.

Thanks,

Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México
Paseo de la Reforma 222
Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México

It appears that broadcast / multicast is broken in the FR could , Is this FR over MPLS or straight FR ?

If straight FR then try a neighbor statement form the hub sites under router rip

router rip

neighbor 192.168.110.2

I put two branches with neighbor command, in HQ´s core and the two branches.

But, nothing changes.

I also put the broadcast option in the frame-relay interface-dlci command. IOS accepts this command, no error message is issued, but the option does not work (IOS bug?).

Paulo

The reason it doesn't work is that these are point-to-point subinterfaces, which means they are broadcast capable anyway. The broadcast keyword only has an impact on point-to-multipoint interfaces.

Can you ping 224.0.0.9?

Russ.W

We can see below sh ip prot for Core and one Branch.

Static routes, I have put to circumvent the problem, are listed.

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

CORE-ROT-001# sh ip prot

Routing Protocol is "rip"

Sending updates every 30 seconds, next due in 11 seconds

Invalid after 180 seconds, hold down 180, flushed after 240

Outgoing update filter list for all interfaces is

Incoming update filter list for all interfaces is

Redistributing: rip

Neighbor(s):

192.168.102.2

192.168.110.2

Default version control: send version 2, receive version 2

Interface Send Recv Triggered RIP Key-chain

FastEthernet0/0 2 2

Serial0/0.1 2 2

Serial0/0.2 2 2

Serial0/0.3 2 2

Serial0/0.4 2 2

Serial0/0.5 2 2

Serial0/0.6 2 2

Serial0/0.7 2 2

FastEthernet0/1 2 2

Automatic network summarization is not in effect

Routing for Networks:

192.168.0.0

192.168.1.0

Interface Send Recv Triggered RIP Key-chain

192.168.102.0

192.168.103.0

192.168.104.0

192.168.105.0

192.168.107.0

192.168.109.0

192.168.110.0

Routing Information Sources:

Gateway Distance Last Update

192.168.107.2 120 00:00:27

192.168.104.2 120 00:00:04

192.168.105.2 120 00:00:17

192.168.110.2 120 00:00:12

192.168.109.2 120 3w0d

192.168.102.2 120 3w3d

192.168.103.2 120 3w0d

Distance: (default is 120)

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

BRANCH10-ROT-002#sh ip prot

Routing Protocol is "rip"

Sending updates every 30 seconds, next due in 24 seconds

Invalid after 180 seconds, hold down 180, flushed after 240

Outgoing update filter list for all interfaces is

Incoming update filter list for all interfaces is

Redistributing: rip

Neighbor(s):

192.168.110.1

Default version control: send version 2, receive version 2

Interface Send Recv Triggered RIP Key-chain

FastEthernet0 2 2

Serial0.1 2 2

Automatic network summarization is not in effect

Routing for Networks:

192.168.10.0

192.168.110.0

Routing Information Sources:

Gateway Distance Last Update

192.168.110.1 120 00:00:16

Distance: (default is 120)

Can you paste in the core config , it looks like you are only advertising 192.168.0.0 192.168.1.0 , is no auto-summary configured ?

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