IPv6 Multicast with mrd6?

Installing and Using OpenWrt
61

at the moment that's what I think.

something like

ip6tables -t mangle -A PREROUTING -p udp  --dst ff::/8 -j HL --hl-set 2

should work, may require you to install packages to get the -j HL target and / or to debug errors I may have made

62

there are so many packages. which one is it ?

63

I have no idea, have a look in the package table on the openwrt site

64

I installes kmod ip6 tables and kmod ipopt
now it seems to get the command

root@OpenWrt:~# ip6tables -t mangle -A FORWARD -p udp --dst ff::/8 -j HL --hl-s
et 2

65

I went to the package table here and entered "HL" in the description:

https://openwrt.org/packages/table/start?dataflt[Description_wiki*~]=HL

which suggests you need "iptables-mod-ipopt" and "kmod-ipt-ipopt"

66

so i will now reset my router. then install those packages and set up the sysconfig and the ttl and it should work ?

67

and the route

but yes, I think so.

PLEASE NOTE: if your switch had MLD snooping, then it wouldn't work. The reason it works right now is that the switch on the WAN side is flooding ipv6 multicast to all its ports. If it had MLD snooping it would not be flooding the UDP to your router, and you'd need some way to send MLDs on the WAN to request that it start.

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68

the Switch I use has MLD snooping according to the product description. But I just find IGMP snooping on the interface settings.

69

it might need MLD snooping turned on somewhere, or maybe a firmware upgrade?

70

Suppose you have a switch with MLD then, here's what needs to happen, and I think you'll need to figure it out on your own because I'm not going to chase down your switch config manuals etc.

  1. When VLC on the LAN starts up listening for a stream it sends a MLD report to ff02::16 saying it wants to receive the stream
  2. The router will receive this on its LAN.
  3. The router should forward this to its WAN:
    ip -6 route add multicast ff02::16 dev eth0.2
  4. You may need a firewall rule to pass these packets, though by default LAN to WAN is allowed, so you might not.

Then the switch should see the MLD report and open up the flood to your router's WAN.

Unlike the need for igmpproxy which needs to listen on LAN and re-broadcast on WAN because IGMP is a separate protocol with no notion of routing, in IPv6 the MLD is just an ipv6 packet using icmpv6 and can be routed like this.

71

ok thanks a lot

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72

You're welcome, I hope you get it working, and if you are able to get MLD working on your switch and test the whole thing, would you come back and give some details of how it worked? :wink: I will use those to update the wiki.

73

I have the newest firmware but mld is missing. I probably won't get it to work without further help. but without MLD snooping i doesn't make sense anyway.

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74

Right you need to have that because the whole point is to deal with the case where the UDP stream isn't already coming to your WAN port. You can perhaps call your switch manufacturer's tech support line or change switches, maybe buy a used sg300 cisco switch off Ebay or a new sg350-10 off amazon

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75

I can only suggest testing without that switch before making a purchase.

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76

yes @mickey84 you should get the HL set to 2 and make sure your routing etc works, and then figure out which switch you need for MLD. It looks like this inexpensive tp-link one has MLD snooping: https://www.amazon.com/dp/B016M1QTS2 but I'd be sure to read the manual pages etc before buying.

77

ok thanks, I'll try without the switch first.

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78

could you please tell me how to set this up correctly ? I set up mc forward already.
I'm also connected directly to the router. No switch involved.

also do I have to change something here maybe ?mld

79

Wait...you haven't done this yet!?!?

You do realize, that's likely your issue. You have a habit of not following all steps, in order.

Also, I noticed my test router had a firewall rule created by pimbd from the last time I assisted you. I altered the zones, the original rule was zone-any/any:

In /etc/config/firewall:

config rule                                     
        option name 'ipv6 multicast forward for ff00::/8'   
        option family 'ipv6'                             
        option proto 'udp'                                  
        option dest_ip 'ff00::/8'                        
        option target 'ACCEPT'                 
        option src 'wan'                                 
        option dest 'lan'

In /etc/config/network:

config route6               
        option interface 'lan'
        option target 'ff00::/8'
        option type 'multicast'
80

Sorry for confusing you guys. ok now I did this on a freshly rebooted router.nothing else configured besides these changes you just posted plus the sysconfig.
I will now also install kmod and iptables6 and setup the HL. is that correct ?