Redistribution brings it up.
What happens is, the link is brought up and OSPF forms an adjacency. Then,
since it is a demand circuit, periodic LSA's are squelched and OSPF routes
associated with those LSA's do not age out of the routing table. Then, the
layer 2 portion of the link drops, since there is no interesting traffic.
Once the link drops, whatever protocol you are redistributing into OSPF sees
it's link drop, and changes its tables in accordance with the topology
change. This change gets redistributed into OSPF, and OSPF floods LSA's out
announcing the change. These LSA's bring up the link while OSPF converges.
Then, after a while, things are stable again, and the link drops - and guess
what? That's right! The whole thing starts again...
There are ways to stop it.
Z
>From: "George Zhang" <[EMAIL PROTECTED]>
>Reply-To: "George Zhang" <[EMAIL PROTECTED]>
>To: <[EMAIL PROTECTED]>, <[EMAIL PROTECTED]>,
><[EMAIL PROTECTED]>, <[EMAIL PROTECTED]>,
><[EMAIL PROTECTED]>, <[EMAIL PROTECTED]>, <[EMAIL PROTECTED]>,
> <[EMAIL PROTECTED]>, <[EMAIL PROTECTED]>,
><[EMAIL PROTECTED]>, <[EMAIL PROTECTED]>
>Subject: Re: bri flapping with demand cirquit/igrp redistribution
>Date: Tue, 27 Mar 2001 13:50:52 -0600
>
>I also had the same problem a few days ago. Here is how I fixed it:
>
>1. Isolate the problem by shutting down all other interfaces besides the
>interfaces
> between the two related routers;
>
>2. Disable all other routing protocols (non-OSPF ones);
>
>3. Turn off IGRP redistribution to OSPF;
>
>3. Now, verify the ISDN demand circuit. It should be quiet now.
>
>4. Now, start unshut the interfaces you have shut down one by one and
>verify
> that the ISDN demand circuit. It should might come up briefly but it
>should go
> down and keep quiet after some interfaces are unshut. If the ISDN
>line
> keep dialing, you should know which interface is causing the problem.
>
>5. If the ISDN line is still quiet after you unshut all interfaces, turn on
>your other router
> protocols such as IGRN, RIP, etc one by one. Again, verify the IDN
>line after
> each change as above.
>
>5. If the ISDN line is still quiet after you enable all other routing
>protocols, turn on your
> redistribution one by one. Again verify ISDN line along the way.
>
>If you follow these steps, you should be able to pin down what is causing
>your ISDN
>line to stay up.
>
>Hope it helps.
>
>George Zhang
>
>
> >>> "Donald B Johnson Jr" <[EMAIL PROTECTED]> 03/27/01 03:33PM >>>
>It may keep the connection open though even after there is no intresting
>traffic.
>Don
>----- Original Message -----
>From: Alan Basinger <[EMAIL PROTECTED]>
>To: Chris Larson <[EMAIL PROTECTED]>; perez claude-vincent
><[EMAIL PROTECTED]>; Ya Wen <[EMAIL PROTECTED]>; Patrick
>Murphy <[EMAIL PROTECTED]>; Leah Lynch <[EMAIL PROTECTED]>; 'Jay
>Chandradas' <[EMAIL PROTECTED]>; 'Bob Boone' <[EMAIL PROTECTED]>;
><[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
>Sent: Saturday, March 24, 2001 8:37 AM
>Subject: RE: bri flapping with demand cirquit/igrp redistribution
>
>
> > CDP may work at layer 2 but if the line is brought up because of web
>traffic
> > CDP packets would then traverse the line consume a small amount of
> > bandwidth.
> > I have installed a few ISDN DDR VPN's without turning off CDP and never
>had
> > and issue but also didn't think about the bandwidth consumption at the
>time.
> >
> > Alan
> >
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
> > Chris Larson
> > Sent: Saturday, March 24, 2001 9:00 AM
> > To: perez claude-vincent; Ya Wen; Patrick Murphy; Leah Lynch; 'Jay
> > Chandradas'; 'Bob Boone'; [EMAIL PROTECTED]; [EMAIL PROTECTED]
> > Subject: RE: bri flapping with demand cirquit/igrp redistribution
> >
> >
> > It may not, I have just always disabled it on dialer links as a habit.
>It
> > makes sense that it shouldn't since the dialer-list defines layer 3
>traffic
> > only. You could always put an access-list on the dialer interface
>permitting
> > all traffic with the log statement to see exactly what is trying to get
> > accross the line. It will output to the console if you are consoled in.
>That
> > may help you to see what is bringing the line up.
> >
> > -----Original Message-----
> > From: perez claude-vincent [mailto:[EMAIL PROTECTED]]
> > Sent: Saturday, March 24, 2001 9:22 AM
> > To: Ya Wen; Patrick Murphy; Leah Lynch; 'Jay Chandradas'; 'Chris
> > Larson'; 'Bob Boone'; [EMAIL PROTECTED]; [EMAIL PROTECTED]
> > Subject: RE: bri flapping with demand cirquit/igrp redistribution
> >
> >
> > Can somebody tell me how come CDP may bring the line
> > up? As you know, it works only in layer 2 as said
> > before. Your dialer-list works at layer 3 & 4 only.
> >
> > Did I miss something? :-(
> >
> >
> >
> > --- Ya Wen <[EMAIL PROTECTED]> wrote:
> > > Try remove the "log" from the access-list 15
> > > associated with the route-map
> > > stuff. Also, you do not need the summary-address
> > > under OSPF.
> > >
> > > -Ya
> > >
> > > -----Original Message-----
> > > From: [EMAIL PROTECTED]
> > > [mailto:[EMAIL PROTECTED]]On Behalf Of
> > > Patrick Murphy
> > > Sent: Friday, March 23, 2001 5:04 PM
> > > To: Leah Lynch; 'Jay Chandradas'; 'Chris Larson';
> > > 'Bob Boone';
> > > [EMAIL PROTECTED]; [EMAIL PROTECTED]
> > > Subject: Re: bri flapping with demand cirquit/igrp
> > > redistribution
> > >
> > >
> > > Also check the BRI interface and see if you see
> > > IPCDP, it should disapper
> > > when you no cdp en!
> > >
> > > Patrick
> > >
> > > ----- Original Message -----
> > > From: "Leah Lynch" <[EMAIL PROTECTED]>
> > > To: "'Jay Chandradas'" <[EMAIL PROTECTED]>; "'Chris
> > > Larson'"
> > > <[EMAIL PROTECTED]>; "'Bob Boone'"
> > > <[EMAIL PROTECTED]>;
> > > <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
> > > Sent: Friday, March 23, 2001 7:45 PM
> > > Subject: RE: bri flapping with demand cirquit/igrp
> > > redistribution
> > >
> > >
> > > > I think you normally disable CDP in dialup lines
> > > for efficiency.
> > > >
> > > > Leah
> > > >
> > > > -----Original Message-----
> > > > From: [EMAIL PROTECTED]
> > > [mailto:[EMAIL PROTECTED]]On Behalf Of
> > > > Jay Chandradas
> > > > Sent: Friday, March 23, 2001 2:57 PM
> > > > To: Chris Larson; Bob Boone; [EMAIL PROTECTED];
> > > > [EMAIL PROTECTED]
> > > > Subject: Re: bri flapping with demand cirquit/igrp
> > > redistribution
> > > >
> > > >
> > > >
> > > >
> > > > I am not sure CDP will keep the line up ? And ur
> > > interesting traffic is
> > > > permit ip any any . I dont think CDP will keep the
> > > line up. When u do a
> > > > debug ip pack.. u can nvr see CDP.. CDP is layer
> > > 2.
> > > >
> > > > my 0.02
> > > >
> > > > ----- Original Message -----
> > > > From: "Chris Larson" <[EMAIL PROTECTED]>
> > > > To: "Bob Boone" <[EMAIL PROTECTED]>; "Jay
> > > Chandradas"
> > > <[EMAIL PROTECTED]>;
> > > > <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
> > > > Sent: Friday, March 23, 2001 2:40 PM
> > > > Subject: RE: bri flapping with demand cirquit/igrp
> > > redistribution
> > > >
> > > >
> > > > > Will CDP keep the line up? Turn off CDP.
> > > > >
> > > > > -----Original Message-----
> > > > > From: [EMAIL PROTECTED]
> > > [mailto:[EMAIL PROTECTED]]On Behalf Of
> > > > > Bob Boone
> > > > > Sent: Friday, March 16, 2001 5:30 PM
> > > > > To: Jay Chandradas; [EMAIL PROTECTED];
> > > [EMAIL PROTECTED]
> > > > > Subject: Re: bri flapping with demand
> > > cirquit/igrp redistribution
> > > > >
> > > > >
> > > > > Yes i do have passive BRI on IGRP, and also, the
> > > way it is done now, it
> > > > > restricts ALL networks, if you look at the
> > > access-list 15 it has one
> > > > > statement and then explisit deny all.
> > > > > still not working.
> > > > >
> > > > > ----- Original Message -----
> > > > > From: "Jay Chandradas" <[EMAIL PROTECTED]>
> > > > > To: "Netguy" <[EMAIL PROTECTED]>;
> > > <[EMAIL PROTECTED]>;
> > > > > <[EMAIL PROTECTED]>
> > > > > Sent: Friday, March 16, 2001 12:22 PM
> > > > > Subject: Re: bri flapping with demand
> > > cirquit/igrp redistribution
> > > > >
> > > > >
> > > > > > 1. DO u have a passive interface on bri0 under
> > > router IGRP
> > > > > >
> > > > > > 2. I wud do this way !! when u r redisributing
> > > into OSPG .. allow only
> > > > the
> > > > > > IGRP networks ( including the network conneted
> > > with is running IGRP )
> > > > > >
> > > > > > Jay
> > > > > >
> > > > > > when u r redistributing into
> > > > > > ----- Original Message -----
> > > > > > From: "Netguy" <[EMAIL PROTECTED]>
> > > > > > To: <[EMAIL PROTECTED]>;
> > > <[EMAIL PROTECTED]>
> > > > > > Sent: Friday, March 16, 2001 12:01 PM
> > > > > > Subject: bri flapping with demand cirquit/igrp
> > > redistribution
> > > > > >
> > > > > >
> > > > > > > > Hello all you happy people.
> > > > > > > > Router A has ospf/igrp mutual
> > > redistribution and bri
> > > > > > > > int dialing elsewhere with demand circuit.
> > > it keeps
> > > > > > > > flapping.
> > > > > > > > i followed someone's advice and created a
> > > route/map
> > > > > > > > filter to filter out bri network from igrp
> > > > > > > > redistributing back into ospf.
> > > > > > > > what the hell am i doing wrong? i know its
> > > a big
> > > > > > > > thing
> > > > > > > > that lots of people had problems with.
> > > > > > > > here's the key configs:
> > > > > > > > interface BRI0/0
> > > > > > > > ip address 173.5.8.1 255.255.255.252
> > > > > > > > encapsulation ppp
> > > > > > > > ip ospf demand-circuit
> > > > > > > > dialer idle-timeout 15
> > > > > > > > dialer map ip 173.5.8.2 name R5 broadcast
> > > 8667007
> > > > > > > > dialer map ip 173.5.8.2 name R5 broadcast
> > > 8667008
> > > > > > > > dialer load-threshold 128 outbound
> > > > > > > > dialer-group 1
> > > > > > > > isdn switch-type basic-dms100
> > > > > > > > isdn spid1 9258667005
> > > > > > > > isdn spid2 9258667006
> > > > > > > > ppp authentication chap
> > > > > > > > ppp chap hostname CCIE
> > > > > > > > ppp multilink
> > > > > > > >
> > > > > > > >
> > > > > > > > router ospf 1
> > > > > > > > log-adjacency-changes
> > > > > > > > area 0 authentication message-digest
> > > > > > > > area 0 range 173.5.1.0 255.255.255.0
> > > > > > > > summary-address 173.5.10.0 255.255.255.0
> > > > > > > > redistribute igrp 100 metric 100 subnets
> > > route-map
> > > > > > > > stuff
> > > > > > > > network 1.1.1.0 0.0.0.3 area 0
> > > > > > > > network 173.5.1.0 0.0.0.15 area 0
> > > > > > > > network 173.5.7.0 0.0.0.7 area 3
> > > > > > > > network 173.5.8.0 0.0.0.3 area 3
> > > > > > > > network 173.5.10.0 0.0.0.127 area 3
> > > > > > > > network 173.5.17.0 0.0.0.255 area 0
> > > > > > > > access-list 15 permit 173.5.8.0 0.0.0.3
> > > log
> > > > > > > > route-map stuff deny 5
> > > > > > > > match ip address 15
> > > > > > > > !
> > > > > > > > route-map stuff permit 10
> > > > > > > > set tag 4
> > > > > > > >
> > > > > > > >
> > > __________________________________________________
> > > > > > > > Do You Yahoo!?
> > > > > > > > Get email at your own domain with Yahoo!
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> > > > > > >
> > > > > > >
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> > > > > > > Get email at your own domain with Yahoo!
> > > Mail.
> > > > > > > http://personal.mail.yahoo.com/
> > > > > > >
> > > > > > >
> > >
> > _______________________________________________________
> > > > > > > To unsubscribe from the CCIELAB list, send a
> > > message to
> > >
> > === message truncated ===
> >
> >
> > =====
> >
> > Vincent
> >
> >
> > __________________________________________________
> > Do You Yahoo!?
> > Get email at your own domain with Yahoo! Mail.
> > http://personal.mail.yahoo.com/
> >
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