ZyXEL Communications 4528F User Manual

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Chapter 39 DVMRP
XGS-4526/4528F/4728F User’s Guide
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The final multicast (“M”) after pruning and grafting is shown in the next figure.
Figure 173   How DVMRP Works 
39.2.1  DVMRP Terminology 
DVMRP probes are used to discover other DVMRP Neighbors on a network. 
DVMRP reports are used to exchange DVMRP source routing information. These 
packets are used to build the DVMRP multicast routing table that is used to build 
source trees and also perform Reverse Path Forwarding (RPF) checks on incoming 
multicast packets. RPF checks prevent duplicate packets being filtered when loops 
exist in the network topology. 
DVMRP prunes trim the multicast delivery tree(s). DVMRP grafts attach a branch 
back onto the multicast delivery tree.
39.3  Configuring DVMRP  
Configure DVMRP on the Switch when you wish it to act as a multicast router 
(“mrouter”). Click IP Application > DVMRP in the navigation panel to display 
the screen as shown. 
Figure 174   IP Application > DVMRP