Frame-relay multilink not working

Answered Question
Aug 22nd, 2008

Hello all!


I have 2 routers, each router has 2 x E1 cards and they are connected back-to-back.

If I configure each pair of E1 individual, with FR everything works fine. I bundle the E1 interfaces into a FR multilink, the MFR interface is UP, multilink is reported UP, but no traffic is passing through it. Everything seems to be fine, but (for example) I cannot ping between this 2 routers.

The strange fact is that when I issue "sh frame-relay pvc" there are no INPUT packets. Debugging is showing me only sent packets.

I changed the frame-relay encapsulation (Cisco / IETF), tried different scenarios / parameters, change MTU size...nothing helped so far.

Do you have any idea, advice for me?


Thanks a lot!


Cheers,

Calin

Correct Answer by Giuseppe Larosa about 8 years 6 months ago

Hello Calin,

it was the no arp frame-relay.

you used LMI keepalive with one side as DCE.


Nice to hear you solved the issue


about the solved symbol only you could set it on someebody else's answer because you have started the thread.



Best Regards

Giuseppe

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Giuseppe Larosa Fri, 08/22/2008 - 22:08

Hello Calin,

use the following link as a reference:


http://www.cisco.com/en/US/docs/ios/12_2s/feature/guide/fs_mfr.html


on the physical interfaces you need


encapsulation frame-relay mfr


To create a multilink Frame Relay bundle link and to associate the link with a bundle, use the encapsulation frame-relay mfr command in interface configuration mode. To remove the bundle link from the bundle, use the no form of this command.


encapsulation frame-relay mfr number [name]


no encapsulation frame-relay mfr number [name]


Example:


interface mfr0

!

interface serial 0

encapsulation frame-relay mfr0 BL1



Hope to help

Giuseppe



Calin Chiorean Sat, 08/23/2008 - 03:21

Hello Giuseppe and thanks for replying.


I believe that I have the configuration OK. I's my fault, I should paste it here, to give you some more information. So here it is:


interface Serial1/0

description -> R1 s1/0

no ip address

encapsulation frame-relay MFR1

serial restart-delay 0

no dce-terminal-timing-enable

no arp frame-relay

frame-relay multilink lid R2_S10


interface Serial1/1

description -> R1 s1/1

no ip address

encapsulation frame-relay MFR1

serial restart-delay 0

no dce-terminal-timing-enable

no arp frame-relay

frame-relay multilink lid R2_S11


interface MFR1

description -> bundle R1

no ip address

no keepalive

frame-relay multilink bid R2


interface MFR1.1 point-to-point

ip address 192.168.0.2 255.255.255.0

frame-relay interface-dlci 101


and the same on the other side.


Also:

R2#sh frame-relay multilink

Bundle: MFR1, State = up, class = A, fragmentation disabled

BID = R2

Bundle links:

Serial1/1, HW state = up, link state = Up, LID = R2_S11

Serial1/0, HW state = up, link state = Up, LID = R2_S10


but I cannot ping the other end :(


Thanks and cheers,

Calin

Giuseppe Larosa Sat, 08/23/2008 - 03:54

Hello Calin,

i would try on one side:


int mfr 1

keepalive

frame-relay intf-type dce


on the other router

int mfr1

keepalive


Just to see if there is any changes


May you post the sh frame-rel map .

After having reenabled keepalive with one side acting as the switch view with sh frame-rel lmi if you get bidirectional communication.


see


frame-relay intf-type dce


Example:

Router(config-if)# frame-relay intf-type dce

Configures a device to function as the data circuit-terminating equipment (DCE).


•Only one end of a link should be configured as the DCE. The other end will function as the data terminal equipment (DTE), which is the default setting.


•This command can be used only if Frame Relay switching has been enabled by entering the frame-relay switching command in global configuration mode.


I know that on back to back single link disabling keepalive is effective to get a working link I'm not sure it is the same with multilink FR.



Hope to help

Giuseppe

Calin Chiorean Sat, 08/23/2008 - 05:29

Hi Giuseppe!


Thanks again for replying!


Above you have some info when the "no keepalive" was in place

sh frame-relay pvc


PVC Statistics for interface MFR1 (Frame Relay DTE)


Active Inactive Deleted Static

Local 0 0 0 1

Switched 0 0 0 0

Unused 0 0 0 0


DLCI = 101, DLCI USAGE = LOCAL, PVC STATUS = STATIC, INTERFACE = MFR1.1


input pkts 0 output pkts 1021 in bytes 0

out bytes 325865 dropped pkts 0 in pkts dropped 0

out pkts dropped 0 out bytes dropped 0

in FECN pkts 0 in BECN pkts 0 out FECN pkts 0

out BECN pkts 0 in DE pkts 0 out DE pkts 0

out bcast pkts 951 out bcast bytes 318585

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

pvc create time 1d02h, last time pvc status changed 15:20:47


-as you can see there are no "input packets" on DLCI 101.


sh frame-relay map

MFR1.1 (up): point-to-point dlci, dlci 101(0x65,0x1850), broadcast


-this seems fine


NOW after modifying according to your advice (keepalive enable, DTE-DCE...):


R1(DCE)

sh frame-relay pvc


PVC Statistics for interface MFR1 (Frame Relay DCE)


Active Inactive Deleted Static

Local 0 1 0 0

Switched 0 0 0 0

Unused 0 0 0 0


DLCI = 101, DLCI USAGE = LOCAL, PVC STATUS = INACTIVE, INTERFACE = MFR1.1


input pkts 0 output pkts 1026 in bytes 0

out bytes 327540 dropped pkts 0 in pkts dropped 0

out pkts dropped 0 out bytes dropped 0

in FECN pkts 0 in BECN pkts 0 out FECN pkts 0

out BECN pkts 0 in DE pkts 0 out DE pkts 0

out bcast pkts 956 out bcast bytes 320260

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

pvc create time 1d02h, last time pvc status changed 00:04:49


sh frame-relay map

MFR1.1 (down): point-to-point dlci, dlci 101(0x65,0x1850), broadcast

status defined, inactive


sh frame-relay lmi


LMI Statistics for interface MFR1 (Frame Relay DCE) LMI TYPE = CISCO

Invalid Unnumbered info 0 Invalid Prot Disc 0

Invalid dummy Call Ref 0 Invalid Msg Type 0

Invalid Status Message 0 Invalid Lock Shift 0

Invalid Information ID 0 Invalid Report IE Len 0

Invalid Report Request 0 Invalid Keep IE Len 0

Num Status Enq. Rcvd 3 Num Status msgs Sent 3

Num Update Status Sent 0 Num St Enq. Timeouts 2545


---continues in next message (characters exceeded 4000) -------

Calin Chiorean Sat, 08/23/2008 - 05:29

---continuing-----



R2(DTE)


sh frame-relay pvc


PVC Statistics for interface MFR1 (Frame Relay DTE)


Active Inactive Deleted Static

Local 0 1 0 0

Switched 0 0 0 0

Unused 0 0 0 0


DLCI = 101, DLCI USAGE = LOCAL, PVC STATUS = INACTIVE, INTERFACE = MFR1.1


input pkts 0 output pkts 0 in bytes 0

out bytes 0 dropped pkts 0 in pkts dropped 0

out pkts dropped 0 out bytes dropped 0

in FECN pkts 0 in BECN pkts 0 out FECN pkts 0

out BECN pkts 0 in DE pkts 0 out DE pkts 0

out bcast pkts 0 out bcast bytes 0

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

pvc create time 00:00:28, last time pvc status changed 00:00:28


sh frame-relay map

MFR1.1 (down): point-to-point dlci, dlci 101(0x65,0x1850), broadcast

status defined, inactive


sh frame-relay lmi


LMI Statistics for interface MFR1 (Frame Relay DTE) LMI TYPE = CISCO

Invalid Unnumbered info 0 Invalid Prot Disc 0

Invalid dummy Call Ref 0 Invalid Msg Type 0

Invalid Status Message 0 Invalid Lock Shift 0

Invalid Information ID 0 Invalid Report IE Len 0

Invalid Report Request 0 Invalid Keep IE Len 0

Num Status Enq. Sent 9588 Num Status msgs Rcvd 0

Num Update Status Rcvd 0 Num Status Timeouts 9587


-on R2 seems that I have no sent / receive LMI packets


Now the MF1 is UP protocol DOWN.


I tried the steps above yesterday also, but I said let's give a shot today too.


Cheers,

Calin



Calin Chiorean Sun, 08/24/2008 - 01:23

Hello again!


So, nobody has any idea what can be wrong there?:(


Thanks again!


Cheers,

Calin

Calin Chiorean Sun, 08/24/2008 - 22:13

Sorry to push the things here, but anyone have any idea why I don't have input packets on the multilink interface?


Thanks!


Cheers,

Calin

Giuseppe Larosa Sun, 08/24/2008 - 23:52

Hello Calin,

I see this:

DLCI = 101, DLCI USAGE = LOCAL, PVC STATUS = INACTIVE, INTERFACE = MFR1.1


the DLCI is still inactive so LMI is not working correctly



sh frame-relay map

MFR1.1 (down): point-to-point dlci, dlci 101(0x65,0x1850), broadcast

status defined, inactive



on R2 from sh frame-rel lmi (DTE)


Num Status Enq. Sent 9588 Num Status msgs Rcvd 0

Num Update Status Rcvd 0 Num Status Timeouts 9587



on R1 from sh frame-rel lmi (DCE)


Num Status Enq. Rcvd 3 Num Status msgs Sent 3

Num Update Status Sent 0 Num St Enq. Timeouts 2545


What releases of IOS and what routers are you using ?

it could be a bug of your release.


Cabling and clocking shoud be fine because the links are working when used in stand alone.

Now, with the configuration of FR LMI you have a confirmation that something is not working.


You can also use debug frame-rel lmi to see if you can see the LMI frames on the routers.


I had tested FR multilink on C7200 using two E1 ports of PA with 8 E1 with the LMI and it worked between two C7206.


I would verify with feature navigator and I would try another IOS release on one or both routers.


Hope to help

Giuseppe

Calin Chiorean Mon, 08/25/2008 - 00:08

Thanks Giuseppe for all help!


I will try your advices and let you know how is working.


Cheers,

Calin

Calin Chiorean Mon, 08/25/2008 - 04:13

Hello!


Giuseppe as I said I'm back with some more info.

I searched for IOS BUGs and features and everything is ok. Upgrading the IOS cannot be taken into consideration now, because of some environmental policies.


I tried ppp multilink instead of FR multilink, and it is working fine, but I cannot transport 2 VRF over this multilink interface because the physical interface can be bundled to only one multilink ppp group and for multiple VRFs I need at leat 2 MU interfaces.


The only thing that is in the Cisco documentation at Restrictions for FRF16.1 is: "The multilink Frame Relay peer device must not send frames that require assembly or reordering." but I have not idea how to check if I send this kind of frames, at this moment.


Thanks for support!


Cheers,

Calin

Giuseppe Larosa Mon, 08/25/2008 - 04:25

Hello Callin,


>> but I cannot transport 2 VRF over PPP multilink


is PPP multilink a VRF access link or a a backbone link ?

As a backbone link you just have to enable MPLS forwarding with MPLS IP.

As VRF access link do the following :

define subinterface of the PPP multilink and associate one with VRF1 and one with VRF2.

I was able to define subinterfaces of a PPP interface.




Hope to help

Giuseppe


Calin Chiorean Mon, 08/25/2008 - 05:18

Regarding:

"I was able to define subinterfaces of a PPP interface."

I could not define subinterfaces:


(config)#int multilink ?

<1-2147483647> Multilink interface number


(config)#int multilink 1 ?


(config)#int multilink 1


(config)#int multilink 1.1

^

% Invalid input detected at '^' marker.


Maybe we are talking about different stuff.


Cheers,

Calin


Giuseppe Larosa Mon, 08/25/2008 - 08:21

Hello Calin,

I agree with you this solution is not possible for you



Best Regards

Giuseppe

Calin Chiorean Mon, 08/25/2008 - 12:27

Giuseppe thanks for all the help and support.

I still don't know yet how to "crack" this problem, but if I will find a solution be sure that I'll post it here.


Cheers,

Calin

Calin Chiorean Tue, 08/26/2008 - 00:35

!!!!SOLVED!!!!


This problem is solved. For those who are interested I found a NOTE specifying that if you have a point-to-point E1 from a provider and this provider is transporting the line over different environments, you have to configure DTE-DCE peers (event if you have point-to-point interface configured) and "arp frame-relay" command should be enabled.

Now it is working. Thank you for all the support!


Cheers,

Calin


P.S. Somebody should hit "this answer solve the problem..." just to be showed solved to others. I cannot do it because it's my post. Thanks!

Correct Answer
Giuseppe Larosa Tue, 08/26/2008 - 02:10

Hello Calin,

it was the no arp frame-relay.

you used LMI keepalive with one side as DCE.


Nice to hear you solved the issue


about the solved symbol only you could set it on someebody else's answer because you have started the thread.



Best Regards

Giuseppe

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