Hi,

Can I have DHCP server running on Dom0 of Xen and have the server assign IP address of the interfaces in DomU coming up. If so how do I do it?

Thanks,
Dhanesh.

well can and should is different. i beleive it is possible but really dom0 should only be used to supply the drivers ect... to xen. anything else compromises the whole purpose. the following is a quote from the xen FAQ at http://wiki.xen.org/wiki/Xen_FAQ_Networking

" Which parts of my network infrastructure should I run in dom0, and which should I run in domU?

Network infrastructure, such as DHCP, DNS and OpenVPN servers, should all run in domUs. Installing such services in dom0 is dangerous, as if the services are compromised, an attacker could access other running VMs.

As a general rule, a domU should be used to perform a small, independent task. Therefore if the OS crashes, or is compromised, the effect is constrained to a small part of your setup. This makes it easier to find the problem, and then fix."

Fair point. But if I have DomU to get IP address through DHCP, how do I do it?

Thanks,
Dhanesh.

honestly i have read alot about xen but yet to run it to any real extent so i can't give you the commands,however, i have run some headless vbox servers with virtual networks and i think the same principles can be applied. mind you there are other set ups other than theses, maybe even better ones. think of your dom0 as the vbox software. it would do the routing and NAT(if needed) for the domU's. you could also have it just bridge one domU to the real router and have that domU also act as router, dhcp and NAT for the internal domU network while the physical router just provides the internet acces. to do this you would need two virtual nics on that particulainr domU, one for the external and one for the internal network. this same set up could also be used to have that domU act as a switch instead of a router to segment the network if you so desire. i really can't get more specific without knowing what you want you virtual network to look and act like. for example do you need remote acces to all the domU's, do you want some isolated from the external network or from certain internal machines, without these and other answers i can't tell you if you need a virtual switch, virtual router, two physical nics on your dom0, two virtual ones on a domU or just the one physical router with dom0 doing the forwarding. all theseare possible set-ups but which is best depends on what you are trying to accomplish