Thanks for your advise, but when I was searching on the internet so I found sources like: http://www.kernel.org/pub/linux/kernel/people/marcelo/linux-2.4/Documentation/networking/tuntap.txt wikipedia http://vtun.sourceforge.net/tun/ ...and many many more. However these sources don´t describe TUN/TAP interface in detail. This ins´t possible, that don´t exit detailed manual:( When the programmers make virtual interfaces(TUN/TAP) so they use these links? They have to know exact function these interfaces. I am not programmer, but I think that describe in these links is insufficient to make own virtual interfaces. For example, when I will want to produce motherboards for Intel processors so I must know how is voltage, number of pins, how processor cooperate with chipset, memory and many many more. My image manual to TUN/TUP is some book or ebook with standarts and description like for example this documentation intel P4 processor. ftp://download.intel.com/design/Pentium4/datashts/303128.pdf Sometimes I find source code, but I search human readable like documentation. I am bankkrupt in this work:( _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel