From: jfaure@sztele.com
Date: Mon Feb 03 2003 - 05:34:33 GMT-3
Hi Aamer:
As I said in my first mail, the ospf event that causes the on demand
circuit to bring up is the lost of the adjacency between the two ends of
the isdn network (when ospf on demand are running here, this ospf adjacency
is up and the hellos and lsa's suppresed). Then, one of the two ends
reports this message:
%OSPF-5-ADJCHG: Process 1, Nbr 133.1.46.1 on BRI1/0 from FULL to DOWN,
Neighbor Down: Too many retransmitions on Demand Circuit
Then, this OSPF topology change causes the on demand circuit to go up.
I knew some of your recommendations about stability in ospf on demand
circuits, but i haven't read about disabling cdp. I'm going to try it. It
maybe the "too many retransmitions" of the error message refers to this.
Anyway, anybody know what this error message means exactly?
Regards
Juan Faure Ferrer
email: jfaure@sztele.com
Lmnea de Negocio de Telematica y CC
Ingeniero de Integracisn de Redes y Sistemas
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SOLUZIONA TELECOMUNICACIONES
Servicios Profesionales de UNION FENOSA
Jerez, 3
28016 MADRID
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Aamer Kaleem
<kaleemaamer@y Para: jfaure@sztele.com,
ahoo.com> ccielab@groupstudy.com
Enviado por: cc:
nobody@groupst Asunto: Re: OSPF ON DEMAND CIRCUIT
udy.com SOMETIMES BRINGS UP
01/02/03 23:27
Por favor,
responda a
Aamer Kaleem
Juan,
Here are some thoughts why OSPF is keeping ot up:
1. Filter ISDN Subnet from redistributing back into
OSPF by EIGRP.
2. To find out what LSA is causing the link to be up
use " debug ip ospf monitor ".
3. Disable cdp on BRI interfaces
4. To verify that it is ospf keeping hte link up, you
can run "debug dialer" that show you the destination
as ospf multicast address.
Please verify that ospf is ran as demand circuit by
using ip ospf interface bri<num> command on each
router.
Hope you find the cause...here is the CCO URL for it :
http://www.cisco.com/warp/public/104/dcprob.html
Regards,
Aamer
--- jfaure@sztele.com wrote:
> Hi Guys!
>
> We are testing OSPF ON DEMAND features in my lab.
> I'm using it over an ISDN
> link with the purpose of backing up the main serial
> link (it's running
> ospf) if it becomes unavailable. Apparently, it's
> working fine, but i'm
> seeing that every 12 hours or so, the on demand
> circuit brings up after a
> message like this:
>
> %OSPF-5-ADJCHG: Process 1, Nbr 133.1.46.1 on BRI1/0
> from FULL to DOWN, Nei
> ghbor Down: Too many retransmitions on Demand
> Circuit
>
> This happens when the ospf adjacency beetween the
> two sides of the isdn
> link goes down (you know ospf on demand suppress
> hellos and ospf lsa's in a
> link type "point-to-point" as i have, then the
> adjacency must keep alive).
> Then, why this adjacency goes down?
>
> There is no topollogical change in the ospf network
> other than this (the
> ospf adjacency trough the isdn link goes down). The
> error i said is
> reported by the end that receives the isdn call
> (this end musn't call, and
> the ond demand feature and dialer maps are
> configured in the other link)
>
> Anybody knows what this error means in a ospf on
> demand environment? Am I
> missing something about this?
>
> Here you are the configs of the two routers:
>
> R3---------main Frame Relay link------R5
> |---------------backup isdn link--------------|
>
>
>
> R5 (the router that must call if the main link goes
> down)
>
> username R3 password 0 CISCO
> ip subnet-zero
> no ip domain-lookup
> isdn switch-type basic-net3
>
> interface Loopback0
> ip address 133.1.5.5 255.255.255.255
> !
> interface BRI0/0
> description enlace backup
> ip address 133.1.35.5 255.255.255.0
> encapsulation ppp
> ip ospf demand-circuit
> dialer map ip 133.1.35.6 name R3 broadcast 7200
> dialer load-threshold 128 either
> dialer-group 1
> isdn switch-type basic-net3
> no peer neighbor-route
> ppp authentication chap callin
>
> interface Serial1/1
> no ip address
> encapsulation frame-relay
> no arp frame-relay
> no frame-relay inverse-arp
>
> interface Serial1/1.2 multipoint
> description ENLACE R2 Y R3
> ip address 133.1.46.1 255.255.255.0
> ip ospf authentication message-digest
> ip ospf message-digest-key 1 md5 6 CISCO
> ip ospf network point-to-multipoint
> ip ospf hello-interval 50
> ip ospf priority 255
> no arp frame-relay
> frame-relay map ip 133.1.46.1 502 broadcast
> frame-relay map ip 133.1.46.2 502 broadcast
> frame-relay map ip 133.1.46.3 503 broadcast
> no frame-relay inverse-arp
>
> router ospf 1
> router-id 133.1.46.1
> log-adjacency-changes
> area 5 virtual-link 133.1.56.6
> redistribute rip subnets tag 30
> network 133.1.5.5 0.0.0.0 area 0
> network 133.1.35.0 0.0.0.255 area 3
> network 133.1.46.0 0.0.0.255 area 0
> network 133.1.56.0 0.0.0.255 area 5
>
> access-list 101 permit ospf any any
> access-list 101 deny ip any host 255.255.255.255
> access-list 101 deny ip host 133.1.5.5 any
> access-list 101 permit ip any any
> dialer-list 1 protocol ip list 101
>
> Related config of R3
>
> username R5 password 0 CISCO
> ip subnet-zero
> no ip domain-lookup
> !
> isdn switch-type basic-net3
> interface Loopback0
> ip address 133.1.3.3 255.255.255.255
>
> interface Serial0/0
> description AREA 0
> ip address 133.1.46.3 255.255.255.0
> encapsulation frame-relay
> ip ospf authentication message-digest
> ip ospf message-digest-key 1 md5 6 CISCO
> ip ospf network point-to-multipoint
> ip ospf hello-interval 50
> ip ospf priority 0
> no fair-queue
> no arp frame-relay
> frame-relay map ip 133.1.46.1 305 broadcast
> frame-relay map ip 133.1.46.2 305 broadcast
> frame-relay map ip 133.1.46.3 305 broadcast
> no frame-relay inverse-arp
>
> interface BRI1/0
> ip address 133.1.35.6 255.255.255.0
> encapsulation ppp
> dialer idle-timeout 0
> dialer-group 1
> isdn switch-type basic-net3
> no peer neighbor-route
> ppp authentication chap
>
> router ospf 1
> router-id 133.1.46.3
> log-adjacency-changes
> redistribute eigrp 2 subnets tag 25 route-map
> onlysum
> network 133.1.3.3 0.0.0.0 area 0
> network 133.1.23.0 0.0.0.255 area 3
> network 133.1.35.0 0.0.0.255 area 3
> network 133.1.46.0 0.0.0.255 area 0
>
> I don't include all the config of the 2 routers,
> only the related to this
> issue.
>
> Any help would be apreciated. Regards
>
>
>
>
> Juan Faure Ferrer
> email: jfaure@sztele.com
>
> Lmnea de Negocio de Telematica y CC
> Ingeniero de Integracisn de Redes y Sistemas
>
----------------------------------------------------------------------------
>
> SOLUZIONA TELECOMUNICACIONES
> Servicios Profesionales de UNION FENOSA
> Jerez, 3
> 28016 MADRID
> tel 91 579 30 00 fax 91 350 72 83
>
---------------------------------------------------------------------------
> .
>
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