I have GRE tunnels setup and working between my office and several remote sites around our area. All routers are RB3011's. I have two remote sites that are using Radio Over IP equipment that requires Multicast. These would be radio receivers/transmitters at the sites that may need to transmit or receive at any time. This is for a radio dispatch application. I am currently running a separate tunneling device within our networks to connect through the GRE tunnel and pass the multicast traffic. I would like to setup our routers to pass that multicast traffic through the existing GRE tunnels, allowing me to get rid of the other tunneling device.
I am not an IT guy so the Multicast setup is very confusing to me.

Here is an example of what I have going with the GRE tunnels that work fine now.
Office 1: WAN IP static xxx.xxx.41.194 LAN: 172.16.0.0/20 GRE Tunnel interface: 10.10.1.17/30 to Location 2 & GRE Tunnel interface: 10.10.1.25/30 to Location 3
Location 2: WAN IP static: xxx.xxx.77.15 LAN: 172.19.0.0/16 GRE Tunnel interface: 10.10.1.18/30
Location 3: WAN IP static: xxx.xxx.186.98 LAN: 192.168.208.0/24 GRE Tunnel interface: 10.10.1.26/30
All three routers have the multicast package installed on them at this time.

I have very good and very reliable connections between these sites through the GRE tunnels. I have been trying to find some detailed instructions on how to setup Multicast in all three routers to pass my ROIP traffic. Can someone please help?

Hi!
As no one answered, I'll try to point you in the right direction. To route multicast across layer 3 interfaces (those GRE you have) you need a multicast routing protocol such as PIM. I am new to the mikrotik environment so I cannot help much with the setup. Maybe this will help:

https://wiki.mikrotik.com/wiki/Manual:M ... ed_example

I have several RoIP devices and have been using Multicast for years now.
While there was a bit of a learning curve I figured it out.
I prefer to use EoIP instead of GRE tunnels.
If you post your configuration without sensitive data, I might be able to get you started in the right direction.

-tp

Folks,
Thank you for the replies and offers to assist. What all info do you need me to export for you to have a better idea where I am now? As I said in the OP the GRE tunnels have been great, but if we need to do something else like EoIP then I will have to try those out and see how it goes before trying the multicast also. I can try to export whatever you need to try to help me out.

Thanks again

W0lt,
Here is most of the info from my office router that needs to do multicast to the site ROSE and MT CB (or SLRMTCB). I have posted most of the firewall, interface, route, and address info. hope this is enough to help.

OFFICE MIKROTIK INFO:


IP Addresses:
# ADDRESS NETWORK INTERFACE
0 ;;; defconf
172.22.16.1/20 172.22.16.0 ether2-master
5 10.10.1.17/30 10.10.1.16 TCI2ROSE
7 10.10.1.25/30 10.10.1.24 TCI2SLRMTCB
15 XXX.XXX.41.194/27 XXX.XXX.41.192 ether1


IP routes:

Flags: X - disabled, A - active, D - dynamic,
C - connect, S - static, r - rip, b - bgp, o - ospf, m - mme,
B - blackhole, U - unreachable, P - prohibit
# DST-ADDRESS PREF-SRC GATEWAY DISTAN
0 A S 0.0.0.0/0 XXX.XXX.41.193
5 ADC 10.10.1.16/30 10.10.1.17 TCI2ROSE
7 ADC 10.10.1.24/30 10.10.1.25 TCI2SLRMTCB

IP Firewall Filter rules:

Flags: X - disabled, I - invalid, D - dynamic
0 D ;;; special dummy rule to show fasttrack counters
chain=forward action=passthrough

1 ;;; Allow Trusted IPs List
chain=input action=accept protocol=gre src-address-list=Trusted IPs log=no log-prefix=""
6 chain=input action=accept dst-address=10.10.1.16/30 log=no log-prefix=""
8 chain=input action=accept dst-address=10.10.1.24/30 log=no log-prefix=""
38 ;;; ROSE forward
chain=forward action=accept src-address=172.19.0.0/16 dst-address=172.22.16.0/20 log=no
log-prefix=""
39 ;;; ROSE Input
chain=input action=accept src-address=172.19.0.0/16 dst-address=172.22.16.0/20 log=no
log-prefix=""
42 ;;; NEW MT CB FORWARD
chain=forward action=accept src-address=192.168.208.0/24 dst-address=172.22.16.0/20
log=no log-prefix=""
43 ;;; NEW MT CB INPUT
chain=input action=accept src-address=192.168.208.0/24 dst-address=172.22.16.0/20 log=no
log-prefix=""
73 ;;; defconf: accept established,related
chain=forward action=accept connection-state=established,related log=no log-prefix=""
74 chain=input action=accept protocol=icmp
75 chain=input action=accept connection-state=established
76 chain=input action=accept connection-state=related
77 ;;; defconf: fasttrack
chain=forward action=fasttrack-connection connection-state=established,related log=no
log-prefix=""
78 ;;; defconf: drop invalid
chain=forward action=drop connection-state=invalid log=no log-prefix=""
79 ;;; defconf: drop all from WAN not DSTNATed
chain=forward action=drop connection-state=new connection-nat-state=!dstnat
in-interface=ether1 log=no log-prefix=""


IP Firewall NAT:

Flags: X - disabled, I - invalid, D - dynamic
9 ;;; ROSE
chain=srcnat action=accept src-address=172.22.16.0/20 dst-address=172.19.0.0/16 log=no
log-prefix=""

11 ;;; NEW MT CB
chain=srcnat action=accept src-address=172.22.16.0/20 dst-address=192.168.208.0/24
log=no log-prefix=""

27 ;;; defconf: masquerade
chain=srcnat action=masquerade out-interface=ether1 out-interface-list=WAN log=no
log-prefix=""

28 chain=srcnat action=masquerade out-interface-list=WAN log=no log-prefix=""
-- [Q quit|D dump|up|down]


IP Firewall Address List:

Flags: X - disabled, D - dynamic
# LIST ADDRESS CREATION-TIME TIMEOUT
6 ;;; ROSE
Trusted IPs XXX.XXX.77.15 oct/15/2019 13:04:37
8 ;;; MTCB
Trusted IPs XXX.XXX.186.98 oct/15/2019 13:04:37


Interface GRE:

Flags: X - disabled, R - running

13 R name="TCI2ROSE" mtu=1400 actual-mtu=1400 local-address=0.0.0.0 remote-address=XXX.XXX.77.15
keepalive=10s,10 dscp=inherit clamp-tcp-mss=yes dont-fragment=no allow-fast-path=no

14 R name="TCI2SLRMTCB" mtu=1400 actual-mtu=1400 local-address=0.0.0.0 remote-address=XXX.XXX.186.98
keepalive=10s,10 dscp=inherit clamp-tcp-mss=yes dont-fragment=no allow-fast-path=yes