in R1 default gateway 30.42.0.1 and it has scr nat to 30.42.0.2 it has some dst nat based on my requirement.
in R3 default gateway 40.42.0.1 and it has scr nat to 40.42.0.2 it has some dst nat based on my requirement.
In R2 default gateway 10.42.0.1 it has scr nat to 10.42.0.2.
pc 1 and pc 2 are sender of multicast and pc 3 pc 4 are receiver.
because we have two upstream I think we can’t use igmp proxy or mfc. instead i used PIM-SM in all routers. For all routers I created a new PIM-SM instance. and all interfaces were added to the interface template.
pc 3 and pc 4 didn’t get traffic. I think it needs RP points. Which router is good in this scenario to be RP? and which interface of that router is good to be RP? Our group Ip is 224.1.1.1 and the address of RP is 30.42.0.1 but It didn’t work. even other interfaces and other routers are selected as RP but it doesn’t work.
please help me?
Thanks so much.
without the configuration of the routers, it is not possible to completely understand where your issues come from.
But for the basics:
PIM does run on top of regular unicast routing, so it is recommended to have a properly configured routing protocol in your network. You can then configure a RP with an address that is redistributed from a loopback interface, for example. NAT is going to make multicast routing way more complicated or maybe even completely unfeasible.
The positioning of the RP in a network is fully dependent on the workload you are going to expect. The shared tree for multicast distribution is built with the RP as root. In a basic configuration every multicast group is initially transported to the RP and then forwarded along the shared-tree.
Moreover the multicast group IP you are using is part of a reserved block. This range should not be used by any application, because this block is reserved for future use. Please consult RFC 5771 and the IANA IPv4 Multicast Address Space Registry tables for valid usable multicast groups.
Until you provide more details and the configuration of the routers, there is nothing I can suggest.
Thanks for your attention
I found the problem.
My original problem is I have 4 pc behind nat(router is Mikrotik ) that are sender of multicast traffic.additionally I have 4 pc behind nat (router is Mikrotik ) that are receiver of multicast. So I need Nat because I don’t want to use lots of Ip addresses. Right now 4 pc use one ip as external so i save Ip address. I need multicast because I don’t want to send the same data multiple times to senders .Also all 4 PCs that send multicast data are sender so I think igmp proxy and MFC is not a good solution because they have just one upstream. I think Igmp snooping is not a good solution because I have Nat and routing and multi subnet ip addresses. I need PIM-SM. When I use src nat router that pimsm is configured on it does not find each other as neighbors. for example router 1 found that router 2 is its neighbor but router 2 can’t find it. if we don’t use src nat neighbor problem is solved but client behind nat they cant reach to RP Point. so How can we have sender and receiver multicast (both of them ) behind nat in mikrotik?
Thanks so much.
My statement from yesterday still stands.
Until you share the configuration of the routers and think about a properly routed setup, there is nothing I can help with.
Why are you trying to save IP addresses? RFC1918 sets aside tens of millions of them for your use in applications like this.
Furthermore, PIM is designed to work in the presence of regular routing, not NAT.
Therefore, make these senders 10.0.0.1 thru 10.0.0.3, and then configure PIM to forward their multicast traffic to the 192 side of the network. Now you aren’t burning 192-side IPs, and PIM works as designed.
Hi guys, when i add these config to mikrotik router
ip firewall nat add chain=srcnat action=accept protocol=pim router
that has pim on it can see each other but still can’t send and receive multicast traffic all the time. sometimes it works well, sometimes it can’t send and receive.
Thanks so much.
My problem is I can’t send and receive multicast traffic from R1 to R3 all the time. sometimes it works correctly and sometimes it doesn’t work. all R1 R2 R3 can see each other as PIM-SM neighbors but it doesn’t work properly.
Thanks so much.
I’d appreciate it if anybody could help me ?
If we have a router that has one interface as external and some internal interface that are connected to PC that send multicast data, pc s are behind nat I want use PIM-SM I configure src nat and Pim protocol and if i set
ip firewall nat add action=accept chain=srcnat protocol=pim
routers interface with pim enable can see each other but if I don’t set these configuration router interface with pim enable can’t see each other properly because of nat. actually I have another router with one interface as external and other as internal with nat and pc behind nat for receive multicast data the same as sender. Sometimes it works properly and can send and receive multicast data but sometimes it doesn’t work. I have to use multicast for sender and receiver because multiple receivers receive the same data ? I have to use Nat because multiple PCs ( sender or receiver of multicast data ) with local ip must have one public IP ( I don’t mean public internet IP I mean translate IP from private IP to other private IP for example translate from 192.168.0.0 to 10.42.0.0) in my network. The sender and receiver are not in the same subnet so I need to use a router. How ever does PIM work in a scenario? is it complex or infeasible? If it is complex, can you help me ? another solution like IGMP proxy ?
Thanks so much.
The way I see it, this architecture resembles two customers using NAT to connect to an ISP, where R1 and R3 are the CPE routers and R2 is the ISP router? If I’ve got that right, then IMHO the simplest solution would be to use IGMP Proxy on R1 and R3, and PIM-SM on R2?