Re: KVM and Networking access

[Narcis Garcia]

Same IP as host: Not possible (host and guest are 2 machines).

Own IP at same LAN level as host:
A) Attaching VM tun/tap device to host's bridge (see bridge-utils too)
B) Another host physical NIC attached to VM; Others can tell better how
to passthrough this device to VM.

If the only to reach is guest's webserver (TCP 80,443) there is a really
simpler solution (example with rtl8139 as guest virtual NIC):
$ qemu -device rtl8139,netdev=net0 -netdev
user,id=net0,hostfwd=tcp:0.0.0.0:80-:80,hostfwd=tcp:0.0.0.0:443-:443

(this is the user mode networking, where guest is isolated in its own
LAN, but here we are forwarding 80,443 ports from host NIC/IP to guest,
same as a WAN/LAN firewall does)


El 10/11/19 a les 19:24, Ruben Safir ha escrit:
> Is anyone aware of a simple KVM and QEMU tutorial to create a virtual
> machine that can be assiged a static IP  so that one can run  a
> webserver from it.
> 
> I wanted to set up my webservers that are running in metal, into vms,
> and have them use the same IP addresses that the metal is now currently
> using.    I'm not so sure why networking for the VM is so hard.
> 
> I've seen situations where servers even have multiple IP addresses
> assinged to systems with virtual network interfaces such as
> 
> eth0.1
> eth0.2
> 
> etc.  Sonic Walls do this.
> 
> Why do I need a whole networking wrapper for the VM.  Can't I just
> assign the virtual network device inside the VM to the ethernet device
> on the metal, as you can will all the other devices, mouse, keyboard,
> tty, sound.  The VM just maps this stuff as part of the VMs inherent
> ability.  Why does networking require an entire wrapper virtual network?
> 
> I've been told the key to doing this is to build a bridge device (so we
> now have a who bunch of new devices).  But I can't find any tutorials to
> do this, just a lot of confusing and, IMO, poorly written documentation.
> 
> I so miss the old days of Linux HowTOs
>