transport ldp target hellos over different AS domains

[labrat]

Hi:

Is there anyway to transport ldp target hellos across different AS domains? assume IGP for those domains are IS-IS.

[mikep]

Hi,

Targeted Hello is just an UDP packet with dest IP address of remote PE (not a multicast address 224.0.0.2).  IMHO it should not be a problem to transport Targeted LDP Hello packet as long as you leak /32 IP addresses of remote PE routers between AS.

Kind Regards

Michael Pergament

Juniper Networks

[labrat]

Thanks Mike:

Well I think, in order for two target hellos see each other and creats a neighbor/ajacency, without creating regular LDP a cloud in bewteen, somehow there must be ptp tunnel between them and this tunnel is capable of deliverying ldp packets, as the knob "ldp-tunlling" under the defintion of MPLS LSP.

Otherwise, in one IGP domain, two remote LDP loopback interfaces will form adjacency, without even enbling LDP everywhere.

Just wondering there is any way I could create a MPLS LSP cross two different autonomous systems (both running IS-IS). 

[mikep]

Hi,

Well I think, in order for two target hellos see each other and creats a neighbor/ajacency, without creating regular LDP a cloud in bewteen, somehow there must be ptp tunnel between them and this tunnel is capable of deliverying ldp packets, as the knob "ldp-tunlling" under the defintion of MPLS LSP.

[Michael] Right. In this case however you would need RSVP running also between ASBRs.

What are you trying to achieve (establish L2 VPN, martini)?In this case I would rather go with BGP-based L2 VPN as it suppors Interprovider VPNs (no LDP or RSVP between ASBRs).

Kind Regards

Michael Pergament

[labrat]

well, the assumption is that there are cisco routers in another ASN. in this case we have to use Martini L2VPN (juniper term L2circuit).

[Faruk]

I am trying to establish l2circuit over two different IGP ( different AS ). so i have to deploy ldp session between PE routers.

LDP session goes up over IGP cloud so i redistributed PE loopback /32 to our IGP cloud ( OSPF ). Also the same rules applied in other AS domain. 

But ldp session flaps so many and there is no connectivity between our l2circut ;

re0> show ldp session ---------------- extensive   
Address: -----------------, State: Operational, Connection: Open, Hold time: 14
  Session ID: -----/--/------

  Next keepalive in 4 seconds
  Active, Maximum PDU: 4096, Hold time: 30, Neighbor count: 1
  Neighbor types: configured-layer2
  Keepalive interval: 10, Connect retry interval: 1
  Local address: local loopback, Remote address: Remote loopback
  Up for 00:00:15
  Last down 00:00:16 ago; Reason: received unexpected EOF
  Number of session flaps: 14309
  Local - Restart: disabled, Helper mode: enabled
  Remote - Restart: disabled, Helper mode: disabled
  Local maximum recovery time: 240000 msec
  Nonstop routing state: Not in sync
  Queue depth: 0
Message type               Total                     Last 5 seconds
                       Sent      Received          Sent      Received
Initialization        22816         14310               0             0
Keepalive             53453         26398             1             0
Notification              0             0             0             0
Address               14316             1             0             0
Address withdraw          6             0             0             0
Label mapping        735787          3547             0             0
Label request             0             0             0             0
Label withdraw           13            66             0             0
Label release            66             4             0             0
Label abort               0             0             0             0