they dont query both hosts.. thats why v2 is backwards compatible. the igmp querier is 'switched off' when a v1 router is detected.
hth, Mark. > -----Original Message----- > From: richard dumoulin [mailto:[EMAIL PROTECTED]] > Sent: Saturday, 17 August 2002 01:29 > To: [EMAIL PROTECTED] > Subject: Re: Multicast DR and IGMP querier [7:51458] > > > Here it is !! That was my confusion, because it seems that > this capability > was added in order to query IGMP version 1 hosts. With IGMP > version 2 it > seems you do not need it. But what happen then if you have > both IGMP v2 and > PIM DR's ?? Do they both query the hosts ? > > Any Multicast expert right there ? > > Regards. > ----- Original Message ----- > From: "Kent Yu" > To: "richard dumoulin" ; > Sent: Friday, August 16, 2002 4:42 PM > Subject: Re: Multicast DR and IGMP querier [7:51458] > > > > Do you mean that in IOS if a router is running PIM and is > a DR, it will > > query even if it sees IGMP query messages from another > router with lower > ip > > address? > > > > Kent > > > > ----- Original Message ----- > > From: "richard dumoulin" > > To: "Kent Yu" ; > > Sent: Friday, August 16, 2002 10:34 AM > > Subject: Re: Multicast DR and IGMP querier [7:51458] > > > > > > > RFC's are great, but have to look also at how Cisco IOS > implements the > > rfc. > > > PIM DR's use IGMP to query the hosts too !! > > > > > > Regards. > > > ----- Original Message ----- > > > From: "Kent Yu" > > > To: "richard dumoulin" ; > > > Sent: Friday, August 16, 2002 4:20 PM > > > Subject: Re: Multicast DR and IGMP querier [7:51458] > > > > > > > > > > Richard, > > > > > > > > As we mentioned yesterday, only routers speak PIM, I am > not sure where > > you > > > > got the impression that PIM DRs query the hosts, > routers only use IGMP > > to > > > > query the hosts. > > > > > > > > I think as many have suggested, nothing is better than > reading the > > specs, > > > in > > > > this case, RFC 2117 should explain this pretty well. > > > > > > > > HTH > > > > Kent > > > > > > > > ----- Original Message ----- > > > > From: "richard dumoulin" > > > > To: > > > > Sent: Friday, August 16, 2002 3:47 AM > > > > Subject: Re: Multicast DR and IGMP querier [7:51458] > > > > > > > > > > > > > Raj Santiago wrote: > > > > > > > > > > > > Hi Richard, > > > > > > > > > > > > > > > > > > Okay your question is basically what is a "IGMP querier and > > > > > > Multicast Designated Router" > > > > > > > > > > > > > > > > > > Igmp querier is the router in charge to see if any > hosts want > > > > > > to listen to a multicast stream. > > > > > > > > > > > > Designated Router is the router is charge to facilitate pim > > > > > > join, prune and register messages(This also depends on the > > > > > > mode of pim your running, im being very abstract here); > > > > > > Basically the multicast routing part. > > > > > > > > > > But it seems to me that the DR will also query the hosts!! > > > > > > > > > > > > > > > > > > Under IGMP version 1, the router with the highest ip address > > > > > > was BOTH the IGMP querier and Designated Router. > > > > > > > > > > > > Under IGMP version 2, the router with highest ip > address is the > > > > > > DR and the router with the lowest ip address is the > IGMP querier. > > > > > > > > > > If I am right, both the DR and the querier will query > the hosts ?? > > > > > > > > > > > > > > > Cheers. > [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=51522&t=51458 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
