ATM0 interface downs then ups every few minutes

[localgareth]

I have a Cisco 877, with IOS 12.3(8).

The router has been working fine for months, but the last two days every few minutes I see this type of entry in my logs, and Internet connection with ADSL is lost:

000031: *Apr 6 09:29:46.663 BST: %LINK-3-UPDOWN: Interface Virtual-Access2, changed state to down

000032: *Apr 6 09:29:46.663 BST: %DIALER-6-UNBIND: Interface Vi2 unbound from profile Di1

000033: *Apr 6 09:29:47.663 BST: %LINEPROTO-5-UPDOWN: Line protocol on Interface Virtual-Access2, changed state to down

000034: *Apr 6 09:29:47.755 BST: %LINK-3-UPDOWN: Interface ATM0, changed state to down

000035: *Apr 6 09:29:48.755 BST: %LINEPROTO-5-UPDOWN: Line protocol on Interface ATM0, changed state to down

000036: *Apr 6 09:30:11.463 BST: %LINK-3-UPDOWN: Interface ATM0, changed state to up

000037: *Apr 6 09:30:12.463 BST: %LINEPROTO-5-UPDOWN: Line protocol on Interface ATM0, changed state to up

000038: *Apr 6 09:30:19.219 BST: %LINK-3-UPDOWN: Interface Virtual-Access2, changed state to up

000039: *Apr 6 09:30:19.219 BST: %DIALER-6-BIND: Interface Vi2 bound to profile Di1

000040: *Apr 6 09:30:22.311 BST: %LINEPROTO-5-UPDOWN: Line protocol on Interface Virtual-Access2, changed state to up

Does anyone know what could be causing this? My ISP tells me nothing on their side is wrong...

Any useful information would be much appreciated.

Gareth

[pkhatri]

Gareth,

While this may not totally solve your problem, you might want to disable OAM managment on your PVC if you have it configured.

For example, if you have the following type of config:

int atm0.32

pvc 8.35

oam-pvc manage

Then, remove the 'oam-pvc manage' config by entering the 'no oam-pvc manage' command.

Pls do remember to rate posts.

Paresh

[localgareth]

Hi Paresh

Thanks for the suggestion, however I do not have oam-pvc manage in my config.

interface ATM0

no ip address

no ip redirects

no ip unreachables

no ip proxy-arp

ip route-cache flow

no atm ilmi-keepalive

dsl operating-mode ansi-dmt

!

interface ATM0.1 point-to-point

no ip redirects

no ip unreachables

no ip proxy-arp

pvc 0/38

encapsulation aal5mux ppp dialer

dialer pool-member 1

!

!

I'm convinced this is an ISP issue, as it has always worked fine before - but my ISP say I must prove it!

Thanks

Gareth

[mitchen]

Gareth,

where are you based? I've been experiencing similar issues here in the UK which I think may be related to BT's rollout of maxDSL.

It seems that, following the upgrade, there is a period when measures are taken to stabilise the line at the maximum speed, and set a fault threshold.

During this period there may be a number of disconnects as it tries to stabilise.

My ISP tells me that it could take around 3days for the stability to be achieved.

This could be what you are experiencing?

[localgareth]

Hi Neil

That could be the same issue. I have 20 ADSL services around the UK, but this one is the only affected service. It's supplied by Demon and is located in Warwick.

Demon refuse to acknowledge this problem, and are making me swap microfilters, cables, and the kitchen sink.

Where abouts are you based?

Gareth

[mitchen]

We've over 70 ADSL connected sites throughout the UK. Only a handful of these are experiencing real service affecting problems with lots of ATM0 up/downs. Though I have noticed this interface flapping, though not as much, on a number of the other routers too.

Don't know if it will help any but you can check if there are any problems at the actual exchange using this site:

http://usertools.f9.net.uk/exchanges/

Though I guess Demon should have been able to tell you if there were any problems there, in any case.

[localgareth]

Strangely, our problem resolved itself overnight! I suspect it was related to this ADSLmax upgrade at this exchange, the dates coincide...

Thanks for the link, v useful.

Gareth