I've been trying to find a way to allow a sever in a certain subnet to send UDP broadcasts over multiple subnets. The scenario is this:
In network A (192.168.1.0/24) we have a backup server (using urbackup), the server uses automatic discovery of LAN hosts using UDP broadcast, every 50 seconds it sends a broadcast, this work fine in network A.
But we also have a remote site (192.168.5.0/24) that also needs to use this backup server, but since auto-discovery doesn't work there, we have to manually add all the servers.
urbackup server will send a UDP broadcast on each specified network interface, so I can add another interface with IP 192.168.5.X, but I need a way to get the broadcast over to the remote site.
I've tried setting up a GRE tunnel and using a bridge to connect the two networks, but that didn't work (either I didn't do it correctly, or I missed something). I've setup two VMs and tried the following:
gre1: ip link set dev ens192 down ip link add gretap1 type gretap local 192.168.1.X remote 192.168.5.X ip link set dev gretap1 up ip link set dev ens192 up brctl addbr br1 brctl addif br1 gretap1 brctl addif br1 ens192 ip addr add 10.0.0.1/24 dev br1 ip link set br1 up gre5: ip link set dev ens192 down ip link add gretap1 type gretap local 192.168.5.X remote 192.168.1.X ip link set dev gretap1 up ip link set dev ens192 up brctl addbr br1 brctl addif br1 gretap1 brctl addif br1 ens192 ip addr add 10.0.0.2/24 dev br1 ip link set br1 up
After messing around with GRE for two days, currently if I try the above configuration it crashes the ESX gre1 is hosted on (no idea why).
Here is our network diagram (we are using pfsense 2.4 on both sites)
I also thought about setting up a L2TP VPN on site B, but can it provide IPs from same subnet as the DHCP?