Subject: Re: Interface ID in kompella-unnum-02

From: "Connell, Jeff" <[email-masked]>
Date: Thu, 5 Oct 2000 15:11:28 -0500

I may be wrong but..

The two values are never used in the same field without any other
indication, right?

In a router-LSA, the router-ID is the IP of the router, and if the link type
is point-to-point, then this is indicated with the type field in the link
information.  The Link Data field can either be a network mask(type 2 or 3)
or an ifIndex (type 1). (p133 RFC2328)  Where else is the ifIndex used in
OSPF?

Jeff.

-----Original Message-----
From: Yakov Rekhter [mailto:[email-masked]]
Sent: Thursday, October 05, 2000 2:22 PM
To: Raftelis, Mike
Cc: [email-masked]'
Subject: Re: Interface ID in kompella-unnum-02 

Mike,

> Hello,
> 	In draft-kompella-mpls-unnum-02.txt, the interface ID field is shown
> to be 16 bits.  Previous e-mails have suggested that the size be increased
> to 32 bits to match the SNMP ifIndex size.  Can this be increased?  

Please bear in mind that the interface index (interface ID) is carried
not just in RSVP/CR-LDP, but in OSPF as well. 

In OSPF with unnumbered links interface ID is carried in the same field
as a plain IP address. At the same time one still need to be able to
distinguish between the case when this field carries an IP address and
the case when this field carries an interface ID. So if we allow interface
ID to be 32 bits, then when this field carries the value 33620225, is
that an IP address (2.1.1.1) or an interface ID (33620225) ?

Yakov.

---

From: Yakov Rekhter <[email-masked]>
Date: Thu, 05 Oct 2000 13:30:41 -0700

Jeff,

> or an ifIndex (type 1). (p133 RFC2328)  Where else is the ifIndex used in

For numbered p2p links (type 1) the Link Data field "specifies the IP interface
address of the associated router interface" (p128 RFC2328).

Yakov.

---

From: Alex Zinin <[email-masked]>
Date: Thu, 5 Oct 2000 16:02:38 -0700

Jeff,

> The two values are never used in the same field without any other

Wrong.
For p2p interfaces we have link-type set to 1, but
we set link ID to IP addr of the interface or its ifIndex
depending on whether it's numbered or not.

Alex.

---

From: Alex Zinin <[email-masked]>
Date: Thu, 5 Oct 2000 16:08:53 -0700

> we set link ID to IP addr of the interface or its ifIndex

I meant link data.

Alex.