[j-nsp] L2circuit martini issue....!

[FAHAD ALI KHAN]

The reason is...If client lastmile goesdown....it will effect only DLCI flag
to DWON....but its FR-CCC flag never down....and if FR-CCC didnt down...it
will never let L2circuit to go down....!

Consider the following diagram,

CE---FR-swtch==(NNI)==Juniper--------Juniper---CE
 |________Backup Link____|

Here CE is connected to FR Switch and that FR switch is connected to Juniper
over NNI. CE also hav a backup link connected directly to Juiper PE. Now
when the primary Link goesdown....FR switch signal Juniper to inactive the
CE DLCI.....Juniper do it but didint down it logical FR link
(FR-CCC)....check these stats carefully....


*show interfaces ds-1/1/2:1.0 *



 Logical interface ds-1/1/2:1.0 (Index 121) (SNMP ifIndex 156)

    Description: *** Client X SITE B ***

    Flags: Point-To-Point *SNMP-Traps Encapsulation: FR-CCC  (FR-CCC
encapsulation)*

  Input packets : 47743200

  Output packets: 43623195

    Protocol ccc, MTU: 1504

      Flags: None

    *DLCI 152*

     * Flags: Down, DCE-Configured (DLCI FLAG is down but FR-CCC FLAG is not
down...causing link to remain UP)*

      Total down time: 53:49:06 sec, Last down: 01:34:06 ago

      Input packets : 47743200

      Output packets: 43623195

If this link is remain UP....untill its FR-CCC goes down.....and it will be
down only when the complete interface (NNI) will down, which is not
possible. Due to this reason.....primary link in L2circuit remain UP and
client cannot use the protected (secondary) link.

I hope this will clear the problem......!

Regards

Fahad

On 1/25/07, Alex <alex.arseniev at gmail.com> wrote:
>
>  Fahad,
> BFD probes directly connected IP neighbors (since it is run over IP) , in
> case of L2circuit it will be CE-CE.
> 803.2ah is scheduled in  future JUNOS releases, AFAIK.
> I'm still not clear why you need to probe CE-PE link. If BFD/IP SLA probes
> would indicate CE-CE connectivity problem on IP level then surely the CE
> should be able to take a remedy action: switch to backup
> link/protect-interface which should be by that time enabled by PE.
> Rgds
> Alex
>
> ----- Original Message -----
> *From:* FAHAD ALI KHAN <fahad.alikhan at gmail.com>
> *To:* Alex <alex.arseniev at gmail.com> ; juniper-nsp<juniper-nsp at puck.nether.net>
>  *Sent:* Thursday, January 25, 2007 4:24 AM
> *Subject:* Re: [j-nsp] L2circuit martini issue....!
>
>
> Alex.....Clear me in one thing....does BFD can probe L2circuit...and this
> probing is done from CE to PE?
>
> This is confusing. and if it can probe L2circuit.....L2circuit will remain
> UP...it didn't depend on the failure of Lastmile of client (when CE connects
> to FR Switch/L2 Switch and NNI/Trunk to PE) as i discuss in my previous
> mail. FR DLCI goes down but its FR-CCC link never. and this cause L2circuit
> to remain UP.
>
> Also Does Juniper M10i/M7i/J-Series Routers supports Ethernet OAM (802.3ah)....if
> yes than sample configuration will be reuired....!
>
> Regards
>
> Fahad
>
>
> On 1/24/07, Alex <alex.arseniev at gmail.com> wrote:
> >
> >  Fahad,
> > In absense of Ethernet OAM you can still use BFD/IP SLA to constantly
> > probe the L2circuit and tear down IGP adjacencies/sink static routes/disable
> > PBR.
> > BTW, you can also use RPM+event/commit scripts on Junipe boxes to
> > accomplish the same thing as Cisco IP SLA does.
> > Cheers
> > Alex
> >
> >
> > ----- Original Message -----
> > *From:* FAHAD ALI KHAN <fahad.alikhan at gmail.com>
> >  *To:* Alex <alex.arseniev at gmail.com> ; juniper-nsp<juniper-nsp at puck.nether.net>
> > *Sent:* Wednesday, January 24, 2007 11:42 AM
> > *Subject:* Re: [j-nsp] L2circuit martini issue....!
> >
> >
> > Your understanding is correct but let me clear some background issues
> > that i discuss few days ago......!
> >
> > Most of our client termination are in a manner that Ethernet clients are
> > terminated over switch and than truncked to Juniper..and FR clients are
> > terminated over NNI between FR switch and Juniper.,....and than they
> > transported over Martini...but the issue is that..when the lastmile of
> > client goes down....Juniper didnt down its CCC state....means....DLCI shows
> > down but not FR-CCC similarly VLAN-CCC is not down.
> >
> > here are the interface stats when Client lastmile goes down.....
> >
> >
> > *show interfaces ds-1/1/2:1.0 *
> >
> >
> >
> >  Logical interface ds-1/1/2:1.0 (Index 121) (SNMP ifIndex 156)
> >
> >     Description: *** Client X SITE B ***
> >
> >     Flags: Point-To-Point *SNMP-Traps Encapsulation: FR-CCC *
> >
> >   Input packets : 47743200
> >
> >   Output packets: 43623195
> >
> >     Protocol ccc, MTU: 1504
> >
> >       Flags: None
> >
> >     *DLCI 152*
> >
> >      * Flags: Down, DCE-Configured*
> >
> >       Total down time: 53:49:06 sec, Last down: 01:34:06 ago
> >
> >       Input packets : 47743200
> >
> >       Output packets: 43623195
> >
> > **
> >
> > **
> >
> > *And DLCI flag DOWN will not cause FR-CCC to down.....and this will
> > cause L2circuit to remain UP. and if the primary link FR-CCC is not
> > down client cann't use the protected interface. *
> >
> > *  *
> >
> > **
> >
> > *show l2circuit connections*
> >
> >
> >
> > Neighbor: A.B.C.D
> >
> > *Interface                 Type  St     Time last up          # Up trans
> > *
> >
> > *ds-1/1/2:1.0{vc 152)      rmt   Up     Dec 26 08:32:09 2006           1
> > *
> >
> > *Local interface: ds-1/1/2:1.0, Status: Up* , Encapsulation: FRAME RELAY
> >
> > Remote PE: W.X.Y.Z, Negotiated control-word: Yes (Null)
> >
> > Incoming label: 102320, Outgoing label: 155888
> >
> >
> >
> > Similar is the case with VLAN transport over Martini....!
> >
> >
> >
> > And this is causing us alot of problem....!
> >
> >
> >
> >
> > On 1/24/07, Alex <alex.arseniev at gmail.com > wrote:
> > >
> > >  Fahad,
> > > My understnding of "protect-interface" feature is that as long as
> > > Primary interface is UP then protect-interface is DOWN, the
> > > protect-interface is activated when Primary fails:
> > > "primary interface has priority over the protect interface and carries
> > > network traffic as long as it is functional. If the primary interface fails,
> > > the protect interface is activated"
> > > http://www.juniper.net/techpubs/software/junos/junos81/swconfig81-vpns/html/l2circuits-examples.html#1018999
> > >
> > > Sort-of "backup-interface" in Cisco speak.
> > > So when PE-A client has 2 last-mile interfaces, one of then Primary
> > > and second one as protect-interface, then in normal conditions the Primary
> > > is UP and protect os DOWN. When primary fails and goes DOWN, protect is
> > > activated and goes UP. Client should be able to recognise the failure if it
> > > is DIRECTLY connected to PE-A and fail over the traffic to
> > > protect-interface. If there is a L2 switch in between then the whole process
> > > should be transparent to the client and it should not even notice the
> > > failover.
> > > Is my understanding of your scenario correct?
> > > Cheers
> > > Alex
> > >
> > > ----- Original Message -----
> > > *From:* FAHAD ALI KHAN <fahad.alikhan at gmail.com>
> > > *To:* Alex <alex.arseniev at gmail.com>
> > > *Cc:* juniper-nsp <juniper-nsp at puck.nether.net>
> > > *Sent:* Wednesday, January 24, 2007 10:16 AM
> > > *Subject:* Re: [j-nsp] L2circuit martini issue....!
> > >
> > >
> > > Well Alex it will help in CE-CE link tracking.....and PE will never
> > > know any thing.....!
> > > But consider a scenario, On PE-A clinet hav two last miles, one
> > > primary and other backup. We configure L2Circuit and set Pri lastmile as
> > > primary link and secondary lastmile as protected one (under the protocol
> > > l2circuit hierarchy). So If PE didnt know abt it and put down Primary link's
> > > CCC/TCC, client cannot use secondary Lastmile.
> > >
> > > In this case use of every CE-CE link tracking methodologies will
> > > fail.....?
> > >
> > > Regards
> > >
> > > Fahad Ali Khan
> > >
> > >
> > > On 1/24/07, Alex <alex.arseniev at gmail.com > wrote:
> > > >
> > > >  Fahad,
> > > > If you are looking for End-to-End failure detection for L2VPN where
> > > > PE-CE links are Ethernet then You can do it either with BFD or IP SLA Cisco
> > > > feature. Please be aware than BFD/IP SLA do not actually bring down the
> > > > interface/subinterface, they either tear down IGP adjacencies (BFD), remove
> > > > static routes (BFD/IP SLA) or disable PBR (IP SLA).
> > > > HTH
> > > > Cheers
> > > > Alex
> > > >
> > > >
> > > >
> > > >
> > > >
> >
>