ISDN backup problem - really confused

sleste · ‎05-24-2005

Hi, I have an ISDN backup problem. Seems to me that everything is working with the ISDN backup dialer when it comes to the physical connection. When my GRE tunnel (using GRE tunnel due to other cirumstances which I will not go into now) goes down due to loss of connectivity, the dialer at the remote site C1712 router fires up the ISDN connection towards the other end, which is a C3660 router. My static routes then spring into action to make it possible to route to the 172.17.0.0/23 network via the ISDN link instead of the main link. The routing tables on both sides then contain routes to their reseptive dialers to route this traffic. However, when performing a ping, no response is received at all! I cannot seem to even ping the IP addresses on the dialer interfaces.

I have trimmed the configs from both routers to just include the necessary information (other interfaces have been removed, etc.).

Is there anyone who can spot where I have gone wrong with the config? ANY help would be greatly appreciated!! :o)

C1712 router:

hostname StokkeTest-router

!

isdn switch-type basic-net3

!

interface BRI0

no ip address

encapsulation ppp

no ip split-horizon

shutdown

dialer rotary-group 1

dialer-group 1

isdn switch-type basic-net3

isdn point-to-point-setup

!

interface Tunnel0

ip address 172.17.62.10 255.255.255.252

backup delay 2 20

backup interface Dialer1

keepalive 5 2

tunnel source Loopback0

tunnel destination 172.17.62.1

!

interface Dialer1

description Backup Connection to Stokke

ip address 172.17.61.26 255.255.255.252

encapsulation ppp

dialer in-band

dialer idle-timeout 60

dialer map ip 172.17.61.25 name C3660_Skodje class dial1 broadcast 5551234

dialer-group 1

ppp authentication chap

ppp chap hostname StokkeTest-router

!

ip classless

ip route 0.0.0.0 0.0.0.0 FastEthernet0

ip route 172.17.0.0 255.255.254.0 Tunnel0

ip route 172.17.0.0 255.255.254.0 Dialer1 10

!

map-class dialer dial1

dialer-list 1 protocol ip permit

C3660 router:

hostname C3660_Skodje

!

isdn switch-type basic-net3

!

username StokkeTest-router password 0 xxx

!

interface GigabitEthernet0/0

description connected to Ethernet Skodje

ip address 172.17.0.2 255.255.254.0

ip nat inside

duplex auto

speed auto

media-type rj45

negotiation auto

!

interface BRI3/0

description ISDN-backup

no ip address

encapsulation ppp

dialer pool-member 1

dialer pool-member 2

dialer pool-member 3

dialer pool-member 4

dialer pool-member 6

isdn switch-type basic-net3

isdn point-to-point-setup

no cdp enable

!

interface BRI3/1

description ISDN-backup

no ip address

dialer pool-member 3

dialer pool-member 1

dialer pool-member 2

dialer pool-member 4

dialer pool-member 6

isdn switch-type basic-net3

isdn point-to-point-setup

!

interface BRI3/2

description ISDN-backup

no ip address

dialer pool-member 3

dialer pool-member 1

dialer pool-member 2

dialer pool-member 4

dialer pool-member 6

isdn switch-type basic-net3

isdn point-to-point-setup

!

interface BRI3/3

description ISDN-backup

no ip address

dialer pool-member 3

dialer pool-member 1

dialer pool-member 2

dialer pool-member 4

dialer pool-member 6

isdn switch-type basic-net3

isdn point-to-point-setup

!

interface Dialer6

description ISDN-backup Slyper Test

ip address 172.17.61.25 255.255.255.252

encapsulation ppp

no ip split-horizon

dialer pool 6

dialer remote-name StokkeTest-router

dialer idle-timeout 60

dialer hold-queue 100

dialer-group 1

no cdp enable

ppp authentication chap

ppp chap hostname C3660_Skodje

!

router eigrp 1

redistribute static

passive-interface GigabitEthernet0/0

network 10.0.0.0

network 172.17.0.0

auto-summary

neighbor 172.17.60.54 GigabitEthernet0/1

!

ip classless

ip route 172.17.90.0 255.255.255.0 Tunnel0

ip route 172.17.90.0 255.255.255.0 Dialer6 10

!

dialer-list 1 protocol ip permit

Richard Burts · ‎05-24-2005

The first thing that I notice is the shutdown command on the BRI on the 1712 router.

I also notice that there is no dial in-band on the dialer interface of the 3660.

I notice that while the 3660 does have a username configured which is for the 1712 there is not any username on the 1712 for the 3660. I do not know whether you cut that out accidentally in preparing the config for posting or whether it is really missing.

If none of these help your problem then it would be helpful if you would run some debugs and post the output. I would suggest debug isdn q931, then debug ppp negotiation, then debug ppp authentication. You can run these one at a time or run them together.

HTH

Rick

HTH

Rick

sleste · ‎05-24-2005

Hi,

and thanx for replying to my post.

Firstly, when I put the "no shut" command under the BRI0 interface on the C1712 router, I constantly get this message at intervals:

StokkeTest-router#conf t

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

StokkeTest-router(config)#int bri 0

StokkeTest-router(config-if)#no shut

*May 16 18:24:26.147: %LINK-3-UPDOWN: Interface BRI0:1, changed state to down

*May 16 18:24:26.147: %LINK-3-UPDOWN: Interface BRI0:2, changed state to down

*May 16 18:24:26.199: %LINK-3-UPDOWN: Interface BRI0, changed state to up

*May 16 18:24:26.215: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0, TEI 97 changed to up

StokkeTest-router(config-if)#

*May 16 18:24:41.295: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0, TEI 97 changed to down

*May 16 18:24:41.327: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0, TEI 97 changed to up

*May 16 18:24:56.395: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0, TEI 97 changed to down

*May 16 18:24:56.427: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0, TEI 97 changed to up

*May 16 18:25:11.491: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0, TEI 97 changed to down

*May 16 18:25:11.527: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0, TEI 97 changed to up

Is this normal?

Secondly, I did as you said in your post a bit too much cutting. This line is in the config for the C1712

username C3660_Skodje password 0 xxx

I will run the debug commands and post them here.

Steffen

Richard Burts · ‎05-24-2005

Steffen

I would not think that the layer 2 going down and quickly back up, and repeating every 15 seconds is normal.

Seeing these messages I would suggest that you start with debug isdn q921 and then do debug isdn q931. I would wait for the debug ppp till there is resolution of the flapping down and up.

HTH

Rick

HTH

Rick

sleste · ‎05-24-2005

Hi again,

I enabled the debugs on the C1712 router as you stated in your reply.

When I disconnected the ethernet0 on the C1712 this is what happened:

*May 16 18:35:30.611: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0, TEI 97 changed to down

*May 16 18:35:30.615: ISDN BR0 Q931: Ux_DLRelInd: DL_REL_IND received from L2

*May 16 18:35:30.643: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0, TEI 97 changed to up

*May 16 18:35:35.207: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0, changed state to down

*May 16 18:35:40.207: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel0, changed state to down

*May 16 18:35:45.691: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0, TEI 97 changed to down

*May 16 18:35:45.695: ISDN BR0 Q931: Ux_DLRelInd: DL_REL_IND received from L2

*May 16 18:35:45.727: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0, TEI 97 changed to up

*May 16 18:35:46.207: %LINK-3-UPDOWN: Interface Dialer1, changed state to up

*May 16 18:36:00.795: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0, TEI 97 changed to down

*May 16 18:36:00.795: ISDN BR0 Q931: Ux_DLRelInd: DL_REL_IND received from L2

*May 16 18:36:00.827: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0, TEI 97 changed to up

*May 16 18:36:15.895: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0, TEI 97 changed to down

*May 16 18:36:15.895: ISDN BR0 Q931: Ux_DLRelInd: DL_REL_IND received from L2

*May 16 18:36:15.927: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0, TEI 97 changed to up

*May 16 18:36:30.995: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0, TEI 97 changed to down

*May 16 18:36:30.995: ISDN BR0 Q931: Ux_DLRelInd: DL_REL_IND received from L2

*May 16 18:36:31.027: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0, TEI 97 changed to up

*May 16 18:36:46.091: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0, TEI 97 changed to down

*May 16 18:36:46.095: ISDN BR0 Q931: Ux_DLRelInd: DL_REL_IND received from L2

*May 16 18:36:46.127: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0, TEI 97 changed to up

*May 16 18:36:52.883: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0, TEI 97 changed to down

I still get the up and down on the LAYER2 as I stated in my last reply. Not sure why it would be doing this. Cable fault? Config fault?

Steffen

Richard Burts · ‎05-24-2005

Steffen

I am not sure what causes this but I have two suggestions. First can you verify that the switch type you specify is correct according to the provider of the ISDN?

Second I notice that you are using this configuration command:

isdn point-to-point-setup

the documentation describes this as being for static TEI but I do not see that you have configured static TEI. I suggest that you remove isdn point-to-point-setup from the config and see if it makes any difference.

HTH

Rick

HTH

Rick

sleste · ‎05-24-2005

Rick

The flapping I seem to have solved with using another cable. I don't get the flapping messages on the LAYER2 anymore.

As for the switch type, I have looked it up and it's the correct one for my country -> Norway.

The new debug shows this after doing all the forementioned debug commands. I only get this result:

StokkeTest-router#debug isdn q921

debug isdn q921 is ON.

StokkeTest-router#debug isdn q931

debug isdn q931 is ON.

StokkeTest-router#debug ppp negotiation

PPP protocol negotiation debugging is on

StokkeTest-router#debug ppp authentication

PPP authentication debugging is on

StokkeTest-router#

*May 16 19:11:43.943: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0, changed state to down

*May 16 19:11:52.943: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel0, changed state to down

*May 16 19:11:58.943: %LINK-3-UPDOWN: Interface Dialer1, changed state to up

And that is about it. Am I missing anything? I would think that the debug would create more feedback? After Dialer1 went up I waited for several minutes, but didn't receive any more debug feedback.

Will be removing the ISDN Point-Point commands now and try again...

Steffen

Richard Burts · ‎05-24-2005

Steffen

I am glad that you fixed the flapping issue with a different cable.

Yes I would expect more output from the debug. It seems to me that either there is some problem with your logging including debug output (but it did get debug output in the previous post where you were running debug isdn q931). Or that the dialer is not doing anything. To verify whether it is doing anything you can run debug dialer.

I will be very interested whether removing the point to point setup command changes anything. (I am not sure that it will, but I think the command is worth removing since it seems to be intended for an environment different from what you are running)

HTH

Rick

HTH

Rick

sleste · ‎05-31-2005

Hi to all who were kind enough to reply,

the problem was fixed last week. There was something wrong with the ISDN connections on the other end. It all seemed to work fine, as I saw the dialer on the other side getting the connection, but it newer routed any traffic. Exactly what was wrong I will never know, but it was definitely something on the ISDN layer. I got a technician from the phone company who set up the ISDN connections for the clients. The ISDNs went through some sort of phone central, so not your basic run-of-the-mill sort of ISDN. At least noe here in my country. The technician called back saying he had tested everything, but made no changes. After saying so, everything worked like a charm. Funny and pretty miraculous, huh?! :) So, my solution must have been that the technician from the phone company really did some changes (as a collegue of mine who was on-site when it happened, said the guy was going through tons of parameters on the phone system), or that the ISDN cables where not totally attached or something in that order? I believe the first to be true, as I had my collegue try out the ISDN points with his laptop and an ISDN card with which he was dialing up and Internet connection. He got connected, but had problems sending and retreiving data.

To be honest, it's not the first time I have had a problem solved miraculously while another technician was going over things and "not doing any changes". :)

In any case, I am happy things are working and so is the client.

Again thanx for all the replies to my thread.

Regards,

Steffen