[j-nsp] Multicast with L2TP on ERX's

[Carl Neenan]

On Sat, 26 Feb 2005 16:27:22 +1300, Craig Whitmore <lennon at orcon.net.nz> wrote:
> 
> 
> Hi there.
> 
> I am trying to get Multicast going over L2TP sessions terminating on an ERX.
> The L2TP works 100% (we have many customers connected at the moment). They
> are all DSL connections with DSL Modems/Routers etc.
> 
> I send back via Radius ERX-Igmp-Enable = enable which should enable IGMP
> (which it does) (shown via show ip igmp interface.),  I can see it sending
> IGMP messages, but none ever are shown as received. (I am sending them from
> the other end which is a DSL connection (say on an Alcatel Speedtouch
> Router)
> 
> I think the problem is the DSL Routers on the other end don't do IGMP
> Proxing properly (but most have that "feature" noted in their specs but give
> no information on it. How to turn it on/off/debug or alike. Or even if they
> suppose multicast groups etc.
> 
> Has anyone got Multicast enabled for L2TP users on the ERX? (any examples ?
> I cannot find any)
> 
> I know how 100% to do the LAN side with MBGP/PIM etc (see
> http://www.mbone.net.nz)
> 
> Thanks
> Craig
> 

Hi Craig

the l2tp interfaces need to be in promiscuous mode,  to check this run
the command shown below -

ERX#sh ip igmp interface tunnel l2tp:13/32/568574
Interface TUNNEL l2tp:13/32/568574 unnumbered on loopback0
Administrative state enabled, Operational state enabled
Interface parameters:
    Version 2
    State Querier
    Query Interval 125 secs, 21 secs before the next query
    Other querier present interval 250 secs
    Maximum response time 100 (in 10ths of a second)
    Last member query interval 10 (in 10ths of a second)
    Robustness 3
    <b>Interface defaults to global promiscuous mode</b>
    No inbound access group
    No inbound access source-group
    Immediate Leave: disabled
    Max-Group limit: No Limit
    Group Count: 0
Interface statistics:
    Rcvd: 57 reports, 0 leaves, 0 wrong version queries
    Sent: 493 queries
    Groups learned: 0

to enable promiscuous mode for the virtual-router do the following -

ERX#config t
Enter configuration commands, one per line.  End with ^Z.
ERX(config)#router igmp
ERX(config-router)#igmp ?
  disable      Disable IGMP protocol administratively
  promiscuous  Configure IGMP promiscuous state
ERX(config-router)#igmp promiscuous ?
  <cr>
ERX(config-router)#igmp promiscuous

Regards

Carl