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Multicast over GRE Tunnel RB3011

Posted: Thu Nov 14, 2019 2:18 am
by twowaygj
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?

Re: Multicast over GRE Tunnel RB3011

Posted: Tue Nov 19, 2019 5:52 pm
by techlord
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

Re: Multicast over GRE Tunnel RB3011

Posted: Tue Nov 19, 2019 6:03 pm
by w0lt
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

Re: Multicast over GRE Tunnel RB3011

Posted: Wed Nov 20, 2019 4:27 am
by twowaygj
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

Re: Multicast over GRE Tunnel RB3011

Posted: Wed Nov 20, 2019 4:59 am
by twowaygj
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