lsleases captures broadcast 'DHCP Request' datagrams and displays the ip, mac and host name from computers in the local network with dynamic ip address.
Did you ever boot up an embedded system (rasperry-pi, cubie, ...), an android device, an virtual machine or anything else with dynamic ip address (dhcp) ? And now you want to know that ip address ? Then lsleases is for your toolbox - check the Usage.
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install lsleases - see Installation
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re-plug / start-up any device with dynamic ip address
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display captured ip, mac and host names.
j@main:~> lsleases Ip Mac Name 192.168.1.189 10:bf:48:xx:xx:xx android-f6c6dca2130b287 192.168.1.122 b8:27:eb:xx:xx:xx raspberrypi 192.168.1.178 00:22:fb:xx:xx:xx laptop
for more info check the MANUAL
Download the corresponding package for your platform from http://github.com/j-keck/lsleases/releases/latest.
Install command:
- Debian based:
sudo dpkg -i lsleases_<VERSION>_<ARCH>.deb - RedHat based:
sudo rpm -i lsleases-<VERSION>.<ARCH>.rpm - Windows: use the installer:
lsleases_<VERSION>_win_installer_<ARCH>.exe - FreeBSD:
sudo pkg add lsleases-<VERSION>_freebsd_<ARCH>.txz
These packages starts the necessary server instance after installation and on boot.
Debian based:
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add the bintray repository:
echo "deb http://dl.bintray.com/j-keck/deb /" | sudo tee /etc/apt/sources.list.d/bintray-j-keck-deb.list -
update your index:
sudo apt-get update -
install:
sudo apt-get install lsleases
RedHat based:
- add the bintray repository:
wget https://bintray.com/j-keck/rpm/rpm -O - | sudo tee /etc/yum.repos.d/bintray-j-keck-rpm.repo
- install:
sudo yum install lsleases
if you on NixOS see lsleases.nix
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install Go from http://golang.org if not already done
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ensure
$GOPATHis properly set and$GOPATH/binis in your$PATH -
download the source code:
go get -u -d github.com/j-keck/lsleases
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go into the source directory
cd $GOPATH/src/github.com/j-keck/lsleases
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build the source code:
go install -ldflags "-X main.VERSION=$(git describe)"
This will build and install the binary under
$GOPATH/bin -
start a server instance:
sudo nohup $GOPATH/bin/lsleases -s & -
see Usage how to use it
necessary steps to start server as non root:
Linux
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create the runtime application data dir (for unix domain socket and to store persistent leases)
sudo mkdir -p /var/lib/lsleases && sudo chown <USER WHO STARTS THE SERVER> /var/lib/lsleases -
to allow non-root users to open a port below 1024 (dhcp sniffer) and use raw sockets (active availability host check (per arping)) set the corresponding capabilities
sudo setcap 'cap_net_raw,cap_net_bind_service+ep' $GOPATH/bin/lsleases
FreeBSD
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create the runtime application data dir (for unix domain socket and to store persistent leases)
mkdir -p /var/lib/lsleases && chown <USER WHO STARTS THE SERVER> /var/lib/lsleases -
allow non-root users to open a port below 1024 (dhcp sniffer)
echo net.inet.ip.portrange.reservedhigh=0 >> /etc/sysctl.conf service sysctl restart
active availability host check (per arping) as non-root under FreeBSD not supported
Windows
- no additional steps necessary
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if you don't see any leases - check your firewall rules. Port 67 (DHCP) needs to be open. For testing you can temporary open port 67 per:
sudo iptables -I INPUT -p udp --dport 67 -j ACCEPT -
CentOS / RHEL distros do not send the hostname in the 'DHCP Request' datagram by default. To include the hostname in the datagram, use:
echo 'DHCP_HOSTNAME=$(hostname -s)' >> /etc/sysconfig/network-scripts/ifcfg-eth0 -
server logs location
- init / SysVinit based:
/var/log/lsleases.log - systemd based:
journalctl -u lsleasesand/var/log/lsleases.log
- init / SysVinit based:
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if you get '... listen udp :67: bind: address already in use' error at server startup - check which program is already listening on port 67
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Linux:
sudo netstat -taupen | grep ":67 " | awk '{print $NF}' -
FreeBSD:
sockstat -l -P udp -p 67
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if you get '... listen udp :67: bind: permission denied' error at server startup
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installed from source: reread installation guide
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binary installation: open and issue
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see Changelog