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I distribute network using vlan, at vlan.1 we already use a public ip, and to extend the services at vlan.11 we using private ip address.

The machine in vlan.1 can ping device in vlan.11 vice-a-versa. But the route wont works either ways without a nat.

Can private ip address mixed with public ip address without nat?

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Can you clarify what you want to accomplish? Usually machines will answer to ip's attached directly to them without going over the network. – Joris Aug 15 '10 at 13:04
up vote 1 down vote accepted

If you're asking if a server can have both a private and a public IP, the answer is yes. From what it sounds like, you have 2 devices on your server, both VLAN tagged. In this case, the server should be able to respond to either IP it has. Perhaps your other hosts are not sitting on the proper VLANs? Have you verified your switch config?

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Thank you for pointing the problems. – Ta Coen Aug 20 '10 at 12:59

Private addresses are non-routable, which means those addresses will not be routed across Internet routers. The addressing may route within your network of routers that you control, but that will more than likely be the limits of the routing functionality for your private IP ranges.

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