Subject: Question on correct response to invalid LDP initialize messages

From: Edward Harrison <[email-masked]>
Date: Thu, 15 Feb 2001 10:39:05 -0000

Hi,

I have a question regarding the correct response to an LDP initialize
message which is missing the Common Session Parms TLV.

RFC 3036 states that upon receipt of an unacceptable initialization message,
an Error Notification should be sent to the peer. Section 2.5.3  states that
the notification should contain a status TLV indicating which parameters are
in error. Section 3.9 defines specific status codes to cover the label
advertisement mode, max PDU length and label ranges being invalid.

I was wondering what status code should be used if the entire Common Session
Parms TLV is missing. The obvious choice would seem to be the Missing
Message Parameters status code, however this is listed in section 9 as being
a non-fatal error (i.e. E bit is set to 0), but obviously an invalid
initialize message will be fatal.

Another option would be to use the Bad Message Length status code (as
without the Common Session Parms TLV the Initialization message is
effectively of an invalid size). This is listed as a fatal error.

What is the correct status code here? Does anyone know what status code
existing implementations of LDP use in this scenario?

Thanks very much,

Ed

----------------
Ed Harrison
Network Convergence Group
Data Connection Ltd
Tel:   +44 20 8366 1177       Fax: +44 20 8366 5084
Email: [email-masked] Web:http://www.dataconnection.com