Subject: CRP priorities

From: Desikan Saravanan <[email-masked]>
Date: Tue, 8 Feb 2000 18:40:17 -0800

As per the RFC,

3.6.1 Sending Candidate-RP-Advertisements

   C-RPs periodically unicast C-RP-Advs to the BSR for that domain.  The
   interval for sending these messages is subject to local configuration
   at the C-RP.

   Candidate-RP-Advertisements carry group address and group mask
   fields.  This enables the advertising router to limit the
   advertisement to certain prefixes or scopes of groups.  The
   advertising router may enforce this scope acceptance when receiving
   Registers or Join/Prune messages.  C-RPs should send C-RP-Adv
   messages with the `Priority' field set to `0'.

Can anyone shed some light on the reason for forcing the CRP advertisements
to have the priority field set to '0'?

Thanks
Des

---

From: Renu Agarwal <[email-masked]>
Date: Wed, 09 Feb 2000 10:28:03 +0530

Hello Desikan,

This is done to prevent the BSR from ignoring the Candidate RP
advertisement information.If the priority is 0 then BSR shall not ignore
the prefix indicated in the C-RP Advt. information.

See section 3.6.2 which says that ..
The BSR may apply a local policy to limit the number of
Candidate RPs included in the Bootstrap message.  The BSR may override
the prefix indicated in a C-RP-Adv unless the `Priority' field is not
zero.

Hope it clarifies,
Regards,
Renu

---

From: Ravi Puvvala <[email-masked]>
Date: Tue, 08 Feb 2000 21:41:38 -0800

The spec should read that "the default priority of CRP advertisement 
messages should be zero".

Later in Section 3.6.2

      2 The BSR adds the RP address to its local pool of candidate
        RPs, according to the associated group prefix(es) in the C-RP-
        Adv message. The Holdtime in the C-RP-Adv message is also stored
        with the corresponding RP, to be included later in the Bootstrap
        message. The BSR may apply a local policy to limit the number of
        Candidate RPs included in the Bootstrap message.  The BSR may
        override the prefix indicated in a C-RP-Adv unless the
        `Priority' field is not zero.
   
The last line indicates that the priority field *can* be set to something
other than zero.

Ravi

Desikan Saravanan writes:

| As per the RFC,
| 
| 
| 3.6.1 Sending Candidate-RP-Advertisements
| 
|    C-RPs periodically unicast C-RP-Advs to the BSR for that domain.  The
|    interval for sending these messages is subject to local configuration
|    at the C-RP.
| 
|    Candidate-RP-Advertisements carry group address and group mask
|    fields.  This enables the advertising router to limit the
|    advertisement to certain prefixes or scopes of groups.  The
|    advertising router may enforce this scope acceptance when receiving
|    Registers or Join/Prune messages.  C-RPs should send C-RP-Adv
|    messages with the `Priority' field set to `0'.
| 
| 
| Can anyone shed some light on the reason for forcing the CRP advertisements
| to have the priority field set to '0'?
| 
| Thanks
| Des