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I have 3 VLANs connected by a Ubuntu box acting as a router. Unicast packets are properly routed (machines can ping across VLANs, etc). I am now trying to get broadcast working. I want to be able to broadcast into another VLAN by sending to that VLANs broadcast address.

How do I get the broadcast to work?

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OK and what is the question? – Petter H Aug 28 '13 at 18:28
I guess broadcast doesn't cross to other vlan when he is broadcasting from one to another? – Danila Ladner Aug 28 '13 at 18:42
@PetterH Clarified question. I want to be able to broadcast and I cannot, so can I reconfigure my router to allow it? – Konstantin Naryshkin Aug 28 '13 at 19:18
What's your use case here? Typically you want broadcasts to be limited to a single L2 segment. – EEAA Aug 28 '13 at 19:48
VLANs divide broadcast domains. That is their purpose. – Zoredache Aug 28 '13 at 19:55

You can't forward broadcasts between two different networks ( that is why they are separate networks ). Instead you need to set up a single IP network ( same network address and netmask ) and bridge the two parts. Have a look at the brctl command from the bridge-utils package to configure a bridge interface and bind the nics to it.

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