Subject: RESV message in RSVP

From: Francis Arts <[email-masked]>
Date: Wed, 17 Jan 2001 10:47:32 +0100

Hello,

I am trying to find out which IP address should be used as the source IP
address of a RESV message in RSVP.

In RFC 2205 I find the following statements:

1) [RFC 2205, p.38, section 3.1.4] states the following:

"The IP source address is an address of the node that sent the message."

2) [RFC 2205, p.39] states the following:

"The NHOP (i.e., the RSVP_HOP) object contains the IP address of the
interface through which the Resv message was sent and the LIH for the
logical interface on which the reservation is required."

From these quotes I understand the following:
* The source IP address in the IP header of a RESV message can be any IP
address configured on the router that originates the RESV message. So
this can but does not have to be the IP address of the interface on
which the RESV message is sent out [refer to quotes of RFC 2205 below].
* The NHOP object in the RESV message has to be the IP address
configured on the interface via which the RESV message is sent out.

This implies that the source IP address in the IP header of the RESV
message and the NHOP object in the payload of the RESV message may but
do not have to carry different IP addresses.

Is this the correct understanding?

Thank you for your reply.

Kind regards,

    Francis.