Hi everyone, I’m hopinh I can gather you all for some assistance on a little project I’m working on.
I have a simple setup with two interfaces, the internal interface containing 2 vifs:
eth0.1: “VLAN 1” - 192.168.1.0/24
eth0.2: “VLAN 2” - 192.168.2.0/24
Upstream of eth0 is a managed L2 switch, with the two VLANS trunked from physical ports. I have a dhcp server and dns forwarder assigned for each vlan, along with the appropriate snat and dnat config, plus some basic firewall. I’m using two separate VLANS for a number of topology (and security) related reasons.
Everything I need works well - devices which connect to the VLAN 1 ports on the managed switch get the correct IP for that VLAN and can connect to devices on VLAN 2 etc through the default routing etc.
Ideally, what I would like, is for both of these subnets to “interact” as if they were one big single subnet.
For the most part this is currently the case, until it comes to udp broadcasts For instance, if I have a printer on VLAN 1, I can’t auto-discover it on VLAN 2. Likewise for any number of “automagical” discovery applications that are used to set up and interact with devices these days.
Is there any way known, to allow a udp packet sent to the broadcast address of either of these vlans to be propagated across to the other vlan?
I think it’s something similar to ip-directed-broadcast but what I actually want to do is tell the router to identify any broadcast received for one subnet, and drop it on both subnets (rather than to be allowed to point the broadcast directly to another subnet). So I don’t think this is what I’m after, but it seems to come up a lot in searches.
I know that subnets should (by default) not allow this behavior, but in a small controlled environment such as this, there’s no reason I can think of for this function not to exist. So I’m hoping there is a switch I can turn on somewhere to enable it.
This question is not about whether the topology is correct for the scenario etc, I just want to know if it can be done this way.
Any ideas gurus?