03-11-2017
Hi,
Firstly, from just looking at a single IP, you can't tell how large the network it's a part of is. You need to know the netmask. So for example, if I had an IP of 192.168.1.10, that doesn't tell you anything at all about how large or small the network I'm a part of is.
But if I tell you the netmask - e.g. 192.168.1.10/24 or 192.168.1.10/255.255.255.0 - then you know it's part of a network of 256 addresses, running from 192.168.1.0 to 192.168.1.255.
If on the other hand I'd told you the netmask was 192.168.1.10/25 or 192.168.1.10/255.255.255.128 - then you'd know it was part of a network of 128 addresses going from 192.168.1.0 to 192.168.1.127.
And again, in every network, the very first address and the very last address are not usable for hosts, as they are reserved for other purposes.
You can also get plenty of other netmasks than the old simple Class A, B, C notation tells you. For instance I could just have easily told you my netmask was 192.168.1.10/28, in which case you'd then be able to calculate that the network I was a part of runs from 192.168.1.0 to 192.168.1.15, and conists of 16 IP addresses.
So just from looking at an IP you can't tell anything about the size of the network. And these days, there are far more netmasks and subnet sizes that are far more common than the old Class A/B/C notation.
This User Gave Thanks to drysdalk For This Post:
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LEARN ABOUT DEBIAN
pbuilder-uml.conf
pbuilder-uml.conf(5) pbuilder pbuilder-uml.conf(5)
NAME
pbuilder-uml.conf - configuration file for user-mode-linux port of pbuilder
DESCRIPTION
/etc/pbuilder/pbuilder-uml.conf contains default values used in pbuilder-user-mode-linux program invocation.
FORMAT
MY_ETH0=tuntap,,,192.168.0.2
Configures ethernet setting used for booting linux. See how rootstrap boots your system, and copy that.
Specify --eth0=slirp,12345,/usr/bin/slirp-fullbolt to use the slirp connection.
UML_IP=192.168.0.3
IP address to use for guest OS.
This can be set to dhcp for obtaining IP address through DHCP.
UML_NETMASK=255.255.255.0
Guest OS netmask
UML_NETWORK=192.168.0.0
Guest OS network
UML_BROADCAST=255.255.255.255
Guest OS broadcast
UML_GATEWAY=192.168.0.1
Guest OS gateway
PBUILDER_UML_IMAGE=${HOME}/uml-image
Guest OS file system image.
UML_MOUNT_TMPFS=no
Whether to mount tmpfs inside the guest image. This is probably mostly useless.
BUILDPLACE=${HOME}/tmp/
The location which build will take place. pbuilder-user-mode-linux will place temporary COW files to there. The user running UML
needs to be able to access that directory.
UML_MEM=128
The amount of memory allowed for UML. Give more value to here.
UML_HOSTNAME=uml-host
The hostname for the UML.
The hostname should be available in /etc/hosts so that hostname -f will be able to return the FQDN.
UML_BUILDRESULT=/directory/of/build/result
The directory where build result of pbuilder-user-mode-linux is stored.
ROOTSTRAP_IMAGESIZE=size-in-megabytes
The size, in MB, of the disk iamge to create. Defaults to 1000.
NOTES
It is advised to set APTCACHEHARDLINK to no in ~/.pbuilderrc. see pbuilderrc(5) for details.
AUTHOR
Initial coding, and main maintenance is done by Junichi Uekawa <dancer@debian.org>.
The homepage is available at http://pbuilder.alioth.debian.org
FILES
/etc/pbuilder/pbuilder-uml.conf, ${HOME}/.pbuilderrc
SEE ALSO
/usr/share/doc/pbuilder/pbuilder-doc.html, pbuilder-user-mode-linux(1), pbuilder(8), pbuilderrc(5), pdebuild(1)
Debian 2003 Jan 8 pbuilder-uml.conf(5)