Subject: Prune AssertWinner

From: vishwas <[email-masked]>
Date: Fri, 13 Nov 98 17:09:00 PST

Hi all,
 In section 5.5, under "Assert received on outgoing interface: " it is   
mentioned that,

1) .... If the value in the Assert is less than ur value, prune the   
interface.

JUST PRUNING THE INTERFACE WONT SERVE THE PURPOSE, in case of following   
topology, WHERE in, assert looser R3 has to send a prune to assert winner   
R1. Else R1 will contine to flood.

                                O
                  ________ |____________
                      |                   |
                R1 O                  O R2
                      |               __ |______
                    P2P                      |
                      |______________O R3
                                          ___ |_______
                                                      |
                                                     O
Explanation :
        R1 is down initially, so R2 is upstream for R3, later when R1   
comes up, it floods data on P2P link, which happens to be R3 outgoing   
interface list, so R3 will send an assert, and R1 will respond back, R1   
wins, R3 Prunes the P2P INTERFACE (As per draft), But unless R3 sends a   
Prune to Assert winner, R1 in this case he will continue to flood as he   
hasent got any prune from downstream (Flood and Prune Funda).

Note : Just pruning the interface would have worked out fine, if we   
replace P2P link by ETHERNET. But to generalise, it SHOULD be mentioned   
in the draft that, Assert Looser should prune the interface and SHOULD   
also send the prune to the Assert Winner (Assert Winner will schedule a   
prune and take appropriate actions by prune overrides and all....)

 -vishu
Regards
Vishwanath S. Edavayyanamath
 --------------------------------------------------------------------------  
 ------------------------
Software Engineer, Future Software Pvt. Ltd, Chennai, India
Ph : +91-44-4330550 (335)
Private e-mail : [email-masked]

---

From: Ahmed A-G Helmy <[email-masked]>
Date: Fri, 13 Nov 1998 07:05:25 -0800 (PST)

> R1. Else R1 will contine to flood.

no... in PIM-DM (the latest spec) the assert winner schedules a prune of 
its interface (the assert winner) until/unless it gets a join... and so 
the scenario that you pointed to will not happen.

[actually I ran into this specific bug for an earlier version and then it 
was fixed in the versions thereafter],

Regs,
-A