Subject: interface index in MPLS implementation...

From: "G.B.Naidu" <[email-masked]>
Date: Mon, 17 Jan 2000 15:34:29 +0530 (IST)

Hi

How is the interface is identified in MPLS implementation? Is it through
interface name or interface index?

We are trying to have index number in forwarding tables. I would like to
know how do I find out the interface index of the interface on which the
packet came in(Incoming packet)? 

Thank you
-- GB

---

From: "G.B.Naidu" <[email-masked]>
Date: Wed, 19 Jan 2000 10:13:02 +0530 (IST)

Hi Ajith,

Thanks a lot for the reply. As you said, all I want is to identify the
interafce on which the packet has came in. 

Please see my comments below

On Wed, 19 Jan 2000 [email-masked] wrote:
> 
> When a packet comes into your forwarder, there would be some place (depends
> very much on your implementation) where you can identify the
> interface from which it came in.  It may part of your 'packet upcall' or it
> may be a an attribute reachable from the  'buffer containing the packet'
> but unfortunately this depends on your implementation, so can't answer more
> specifically than that.

I like to know how I can identify the interface from which packet came in.
I am trying to implement MPLS on FreeBSD. Can someone please let me know
how do I do this.

> BTW, what router platform are you working on ?  gated ? zebra ? or
> something else ?

It is not yet known. Mopstly it will be gated. We are yet findout from
customer what's the routing protocols they would like to support on the
system. Most probably BGP, OSPF, RSVP stuff.

regards
--gbnaidu

 > 
> best wishes
> -- Ajith
> 
> |   Ajith Narayanan
> |   IBM Emerging Technology Centre
> |   [email-masked]   Tel: (65) 320-1939   I-VPN No: (61-11-8) 979-1939
> Fax: (65) 224-5260
> |   IBM Singapore Pte Ltd, IBM Towers, 80 Anson Rd, Singapore 079907
> --
> 
> 
> "G.B.Naidu" <[email-masked]> on 01/17/2000 06:04:29 PM
> 
> To:   [email-masked]
> cc:    (bcc: Ajith Narayanan/Singapore/IBM)
> Subject:  interface index in MPLS implementation...
> 
> 
> 
> 
> Hi
>

---

From: [email-masked]
Date: Thu, 27 Jan 2000 14:17:30 +0800

> I am trying to implement MPLS on FreeBSD. Can someone please let me know

one possible way is to use the IP_RECVIF socket options in the recvmsg()
call to return the interface index info.  I believe this socket option
should be available on FreeBSD.  For details on how to use it, you can
refer to Stevens's Unix Network Programming book (2nd edition), chapter 13
and 20.
However, be cautioned that this option is not available in all unix
platform.

or alternatively you can try create multiple sockets binding to different
interfaces as what is being done by Jim Leu's linux implementation (though
personally I never get it to work for multicast case).

Regards,
Kheng Kok

---------------------------
Mar Kheng Kok
IBM Emerging Technology Centre
Tel: 320-1086 (Direct)
Fax:  224-5260
Internet: [email-masked]