[j-nsp] status-vector in VPLS?

Marlon Duksa mduksa at gmail.com
Fri Aug 1 10:23:55 EDT 2008


Also, if I turn on BGP trace on Junipers, I won't see this status vector in
BGP update messages. Is it possible that it is not decoded within debuging
component in M320?
I see the rest of the NLRI, but not the status vector.
Thanks
Marlon
On Fri, Aug 1, 2008 at 7:11 AM, Marlon Duksa <mduksa at gmail.com> wrote:

> Thanks.
> I attached a jpeg of the capture and highlighted the VPLS NLRI. There is
> one nibble left at the and 0x1. Or bin 0001.
>
> Is this it? If the CE-ID in this case is 4, what would 0x1 mean in this
> case?
>
> Please note that the whole unhighlighted field is 0x11, but this is wrong
> as the last nible (1) is part of the demux label (wireshark problem). Only
> the last 0x1 is undecoded so I assume that this would be a status vector?
>
> This 0x1 doesn't change regardless of whether is mu ce-interface up or
> down, so I don't understand what status it would indicate?
>
> Thanks,
> Marlon
>
>
>
>
> On Thu, Jul 31, 2008 at 10:10 PM, Munish Saini <msaini at ixiacom.com> wrote:
>
>>  Hi,
>>
>>
>>
>> You should be able to see it in BGP Update Message, a sub-tlv under
>> MP_REACH_NLRI -> NLRI. I don't think that it is decoded in Wireshark or
>> Ethreal. But you should be able to see at the Hex decimal values by clicking
>> above & below the NLRI tlv, there must be some missing Hex values which are
>> not encoded & shown in the Packet stack tree. J
>>
>>
>>
>>
>>
>> Thanks
>>
>>
>>
>> Munish Saini
>>  ------------------------------
>>
>> *From:* Marlon Duksa [mailto:mduksa at gmail.com]
>> *Sent:* Thursday, July 31, 2008 6:20 PM
>> *To:* Munish Saini
>> *Cc:* juniper-nsp at puck.nether.net
>> *Subject:* Re: status-vector in VPLS?
>>
>>
>>
>> Great. Thanks. Munish.
>>
>> I've never be able to observe this status vector in Wireshark and I
>> captured l2vpn BGP updates many times. Does  Wireshark (Ethereal)
>> encoder support this status vector? Is there any extension or update that
>> I need to apply to the Wireshark to be able to see a complete MP_REACH_NLRI?
>>
>> Marlon
>>
>> On Wed, Jul 30, 2008 at 10:16 PM, Munish Saini <msaini at ixiacom.com>
>> wrote:
>>
>> Hi,
>>
>> Status vector means Bit vector advertising the state of local PE-CE
>> circuits to remote PE routers. A bit value of 0 indicates that the local
>> circuit and LSP tunnel to the remote PE router are up, whereas a value
>> of 1 indicates either one or both are down.
>>
>> It is basically Layer 2 VPN and VPLS network layer reachability
>> information (NLRI).
>>
>> RFC CUT Section 5.1.7 of "draft-kompella-ppvpn-l2vpn-03.txt"
>>
>> Circuit Status Vector
>>
>>   A new sub-TLV is introduced to carry the status of an L2VPN PVC
>>   between a pair of PEs.  This sub-TLV is a mandatory part of
>>   MP_REACH_NLRI.
>>
>>   Note that an L2VPN PVC is bidirectional, composed of two simplex
>>   connection going in opposite directions.  A simplex connection
>>   consists of the 3 segments: 1) the local access circuit between the
>>   source CE and the ingress PE, 2) the tunnel LSP between the ingress
>>   and egress PEs, and 3) the access circuit between the egress PE and
>>   the destination CE.
>>
>>   To monitor the status of a PVC, a PE needs to monitor the status of
>>   both simplex connections.  Since it knows that status of its access
>>   circuit, and the status of the tunnel towards the remote PE, it can
>>   inform the remote PE of these two.  Similarly, the remote PE can
>>   inform the status of its access circuit to its local CE and the
>>   status of the tunnel to the first PE.  Combining the local and the
>>   remote information, a PE can determine the status of a PVC.
>>
>>   The basic unit of advertisement in L2VPN for a given CE is a label-
>>   block.  Each label within a label-block corresponds to a PVC on the
>>   CE.  So its natural to advertise the local status information for all
>>   PVCs corresponding to a label-block along with the label-block's
>>   NLRI.  This is done by introducing the circuit status vector TLV.
>>   The value field of this TLV is a bit-vector, each bit of which
>>   indicates the status of the PVC associated with the corresponding
>>   label in the label-block.  Bit value 0 indicates that the local
>>   circuit and the tunnel LSP to the remote PE is up, while a value of 1
>>   indicates that either or both of them are down.
>>
>>   PE A, while selecting a label from a label-block (advertised by PE B,
>>   for remote CE m, and VPN X) for one of its local CE n (in VPN X) can
>>   also determine the status of the corresponding PVC (between CE n and
>>   CE m) by looking at the appropriate bit in the circuit status vector.
>>
>>   Type field for the circuit status vector TLV is TBD.
>>
>>   The length field of the TLV specifies the length of the value field
>>   in bits.  The value field is padded to the nearest octet boundary.
>>
>>   Note that the length field corresponds to the number of labels in the
>>   label-block, i.e., the label-block range.  Label-block range enables
>>   a CE to select a label block (among several label-blocks advertised
>>   by a CE) when picking the VPN label for sending traffic destined to
>>   the CE this label-block corresponds to, such that : received
>> label-block
>>   offset <= local CE id < received label-block range.
>>
>>
>>
>> Thanks
>>
>> Munish Saini
>>
>> -----Original Message-----
>> From: juniper-nsp-bounces at puck.nether.net
>> [mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of
>> juniper-nsp-request at puck.nether.net
>> Sent: Thursday, July 31, 2008 9:13 AM
>> To: juniper-nsp at puck.nether.net
>> Subject: juniper-nsp Digest, Vol 68, Issue 59
>>
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>> Today's Topics:
>>
>>   1. status-vector in VPLS? (Marlon Duksa)
>>   2. vpls remote mac learning on M20 on Junos 9.1? (Marlon Duksa)
>>   3. Re: vpls remote mac learning on M20 on Junos 9.1? (Harry Reynolds)
>>   4. Re: vpls remote mac learning on M20 on Junos 9.1? (Marlon Duksa)
>>
>>
>> ----------------------------------------------------------------------
>>
>> Message: 1
>> Date: Wed, 30 Jul 2008 14:53:52 -0700
>> From: "Marlon Duksa" <mduksa at gmail.com>
>> Subject: [j-nsp] status-vector in VPLS?
>> To: "juniper-nsp at puck.nether.net" <juniper-nsp at puck.nether.net>
>> Message-ID:
>>        <a89d89ac0807301453j107848a3x5644fceadf3b440c at mail.gmail.com>
>> Content-Type: text/plain; charset=ISO-8859-1
>>
>> Does anyone know what this status-vector below in 'show vpla connections
>> extensice' mean? It is in bold red below.
>> How can it be interpreted?
>> Thanks
>>
>> admin at re-0# run show vpls connections extensive
>> Layer-2 VPN connections:
>>
>> Legend for connection status (St)
>> EI -- encapsulation invalid      NC -- interface encapsulation not
>> CCC/TCC/VPLS
>> EM -- encapsulation mismatch     WE -- interface and instance encaps not
>> same
>> VC-Dn -- Virtual circuit down    NP -- interface hardware not present
>> CM -- control-word mismatch      -> -- only outbound connection is up
>> CN -- circuit not provisioned    <- -- only inbound connection is up
>> OR -- out of range               Up -- operational
>> OL -- no outgoing label          Dn -- down
>> LD -- local site signaled down   CF -- call admission control failure
>> RD -- remote site signaled down  SC -- local and remote site ID
>> collision
>> LN -- local site not designated  LM -- local site ID not minimum
>> designated
>> RN -- remote site not designated RM -- remote site ID not minimum
>> designated
>> XX -- unknown connection status  IL -- no incoming label
>> MM -- MTU mismatch               MI -- Mesh-Group ID not availble
>>
>> Legend for interface status
>> Up -- operational
>> Dn -- down
>>
>> Instance: vpls
>>  Local site: green (2)
>>  Number of local interfaces: 2
>>  Number of local interfaces up: 2
>>  IRB interface present: no
>>    ge-5/0/0.0
>>    ge-5/0/0.1
>>    lsi.1048576         1         Intf - vpls vpls local site 2 remote
>> site
>> 1
>>    lsi.1048577         3         Intf - vpls vpls local site 2 remote
>> site
>> 3
>>          262145           1         8       100
>>    *status-vector: 5F *
>>    connection-site           Type  St     Time last up          # Up
>> trans
>>    1                         rmt   Up     Jul 30 21:40:47 2008
>> 1
>>      Local interface: lsi.1048576, Status: Up, Encapsulation: VPLS
>>        Description: Intf - vpls vpls local site 2 remote site 1
>>      Remote PE: 1.1.1.1, Negotiated control-word: No
>>      Incoming label: 262145, Outgoing label: 262146
>>
>>    Connection History:
>>        Jul 30 21:40:47 2008  status update timer
>>        Jul 30 21:40:47 2008  PE route changed
>>        Jul 30 21:40:47 2008  Out lbl Update                    262146
>>        Jul 30 21:40:47 2008  In lbl Update                     262145
>>        Jul 30 21:40:47 2008  loc intf up                  lsi.1048576
>>
>>
>> ------------------------------
>>
>>
>>
>
>


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