From: Tim Fletcher (tim@fletchmail.net)
Date: Wed Dec 18 2002 - 12:29:20 GMT-3
Adash,
In order to get any bandwidth reduction benefit from multicast, you have to
have a shared media. Tunnels are (virtual) point to point media. The router
will do the replication, but it will then have to encapsulate each packet
in each tunnel and send them separately. There is no way to send a packet
through tunnel 1 and have it arrive at destination 2.
-Tim Fletcher
At 10:45 AM 12/18/2002 +0530, Adarsh Singh wrote:
>Hi Joe ,
>
>Yes the scenario is as you have described the source is multicast server on
>LAN & the receivers are through tunnel from router 1, is there a way I can
>decrease the traffic at the serial interface when both receivers are using
>the multicast traffic , I am expecting router 1 to do the replication of the
>traffic going tunnels, which is not happening , since the traffic on the
>serial keeps increasing as I increase the number tunnels, is there a way
>around to keep the traffic between the Router to Router1 constant to the
>multicast traffic , inspite of adding number of tunnels.
>
>
>Rgds
>Adarsh
>----- Original Message -----
>From: "Joe Chang" <changjoe@earthlink.net>
>To: <ccielab@groupstudy.com>
>Sent: Tuesday, December 17, 2002 11:34 PM
>Subject: Re: Multicast ISSUE
>
>
> > It seems that you have enabled pim on the physical interfaces between all
> > the routers, as well as between the tunnel endpoints (assuming the tunnels
> > for R2 and R3 end at the multicast server.) When the network first starts
>up
> > the leaf routers will have to choose whether to use its tunnel or physical
> > interface as its RPF interface for group 239.255.255.255. Since the tunnel
> > is only one hop back to the source, the prune will be requested for the
> > physical interface. The server router will then prune its serial interface
> > from its oil list, and have to send out one multicast packet for each
> > tunnel, thereby doubling the traffic.
> >
> > ----- Original Message -----
> > From: "Adarsh Singh" <adarshs@hclinfinet.net>
> > To: "Don" <seadon@attbi.com>; "Sean Garrett" <SGarrett@cnitech.com>
> > Cc: <ccielab@groupstudy.com>
> > Sent: Tuesday, December 17, 2002 1:40 AM
> > Subject: Multicast ISSUE
> >
> >
> > > Hi Don,
> > >
> > > I have this typical problem with multicast :
> > >
> > > Multicast Server(router)----LL(64Kbps)----Router
>1-----tunne1 ----R2(each
> > > tunnel traffic is 20 Kbps)
> > >
> > > ------tunnel2 ---R3
> > >
> > >
> > > Now as the number of tunnels(gre) increases at the router 1 , the
>traffic
> > > increases propotinally for the 64 Kbps leased line .
> > > So the mulicast is not taking place in real sense .
> > >
> > >
> > >
> > > The commands used at tunnel are as follows :
> > >
> > > interface Tunnel2
> > > ip address 172.168.12.1 255.255.255.252
> > > ip directed-broadcast
> > > ip pim sparse-dense-mode
> > > ip igmp join-group 239.255.255.255
> > > load-interval 30
> > > tunnel source 10.65.12.233
> > > tunnel destination 10.74.5.9
> > >
> > > interface FastEthernet0
> > > description connected to EthernetLAN
> > > ip address 192.168.10.85 255.255.255.0 secondary
> > > ip directed-broadcast
> > > ip pim sparse-dense-mode
> > > ip igmp join-group 239.255.255.255
> > > load-interval 30
> > > speed auto
> > > half-duplex
> > >
> > >
> > > interface Serial1
> > > description connected to infinet for VPN
> > > ip address 10.65.7.82 255.255.255.252
> > > ip accounting output-packets
> > > ip pim sparse-dense-mode
> > > ip igmp join-group 239.255.255.255
> > > load-interval 30
> > >
> > >
> > > Do let me know if someone has ideas of where i an making a mistake.
> > >
> > >
> > > Rgds
> > > Adarsh Singh
> > > .
> > .
>.
.
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