Hi.

I want to setup next configuration:
dom0 running dhcp server for domUs, dhcp shouldn't be accessible from external network, domUs should get additional static routes and ip aliases (if such exist for specific domU) from dhcp.
How do i do this?

Regards, Daniel.

Well, what kind of Xen networking you're using? Bridged, routed, NATed?
If you're using a bridge, you can configure your DHCP server to listen for connections only from the Xen bridge - xenbr0 or something.

I'll set any networking method if required. Main problem is to don't send dhcp requests from domUs to external network and don't accept dhcp requests from external network. In case of banal dhcpd xenbr0 it fails both purposes and i have to make firewall to drop those packets.

I thought about next config:
create virtual network with domUs on dummy0 interface, put dhcp there,
enable ip_forward, set dom0 as router for domUs using dhcp configuration.
this approach has only one flow: all my domUs got different cidrs, so i'll have to manually add them to dom0s routing table.
if i could make dhcpd to add routes according to static leases (looks stupid, i know, but i need 0-configuration networking) this approach would be the best.

Try the BRouter networking approach. That's what I'm using to achieve exactly what you want: have domUs fully separated from external network, and easily connecting each other if needed.