tested on: hostnamectl Static hostname: DebianLaptop Icon name: computer-laptop Chassis: laptop Operating System: Debian GNU/Linux 8 (jessie) Kernel: Linux 3.16.0-4-686-pae Architecture: x86 i assume you have your laptop/pc LAN connected to a switch/router and your default network card is eth0. […]
Wifi Modes of an Access point: DLink has painted a nice overview over the possible different modes of an Accesspoint: cybersec: from great wifi modes that allow bridging two wifi networks, it would be GREAT if vendors test their products […]
on the one hand – software biodiversity is good – if one system get’s hacked or virus infiltrated – the other’s – if “different enough” probably stay unaffected. on the other hand – if config files or procedures or command […]
they essentially do the same – testing the router packages take to a certain destination – meassure time to travel. apt-get install iputils-tracepath; # to install tracepath on debian8, Tools to trace the network path to a remote host strangeness […]
per default debian is not configured to forward traffic. on server/router/gateway: ping yahoo.de; # make sure internet connection works ifconfig eth0:0 192.168.1.1 netmask 255.255.255.0 up; # add additional ip vim /etc/sysctl.conf # Uncomment the next line to enable packet forwarding […]
what service/program is using what port: https://dwaves.de/2015/06/16/linux-list-all-open-ports-and-listening-services/ IPTraf, Iftop, vnstat, bwm-ng, ifconfig -a graphical: gives you overall statistics the blue stuff on the left: iptraf manpage: iptraf-ng.man.txt you probably want to let it run in a screen session, in order […]
show the ARP cache every network interface card (NIC)/LAN network card has a unique-as-possible vendor-asigned MAC address in the format 00:15:5d:00:07:08 this address is changeable like this: ip link set dev eth0 down; ip link set dev eth0 address 00:15:5d:00:07:09; […]
simple but usefull – you have the ip address of an computer in your local LAN – but you don’t know it’s computername. for internet-usage the host command is usefull because it shows – if a website is reachable by […]
IPv4 CIDR Subnet Mask Notation The CIDR number comes from the number of 1’s in the subnet mask when converted to binary. The common subnet mask 255.255.255.0 is 11111111.11111111.11111111.00000000 in binary. This adds up to 24 1’s, or /24 (pronounced […]
Private IPv6 address range If you have multiple locations/sites/networks, you should assign each one a different “Subnet ID”, but use the same “Global” ID for all of them. The IPv6 address space is so huge (2128) that everyone should be […]
IPv6: Goodbye to broadcast, say hello to Multicast » IPv6 while broadcast sends the traffic to all computers in the network – multicast follows a “subscribe to service” model. broadcast -> a computer using ARP sends a packet to FF:FF:FF:FF:FF:FF […]
the DNS system is basically the yellow pages – the phone book of the internet or any network. starting of as a single file (/etc/hosts) – to a world wide self-synchronizing system – that has grown over decades – meaning […]
what for? various reasons. for example maybe the user wants to test download bandwidth by downloading a large file with random data and measure the bandwidth speed. lsb_release -a; # tested on No LSB modules are available. Distributor ID: Debian […]
routing is all about – TCP/IP and the route traffic/packages must/need/can take to the target (webserver, mailserver, youtube.com) and back. alias = “virtual network card” = you can have multiple ip-addresses per phyisical network card. under linux the naming is: […]
ip is the new ifconfig # show all network interfaces (physical and virtual) and their properties ip address show # or in short: ip a s 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback […]
you can check your machine’s current ip with: ip addr show to modify your network interface address setting simply use the nmtui tool: this failed me once with “no Update2” method… so let’s move on to the… manual way: terminal […]
“IPv4 was implemented in 1981, the Internet has grown dramatically, and there are no more available IPv4 addresses – Get Your Network Ready for IPv6 – The last block of IPv4 addresses have been allocated, and it’s time to get […]
one-liner: su – root ip -c a; # what is wifi nic name service NetworkManager stop iwconfig wlp3s0 essid ‘HotelWifiWithNoPassword’ iwconfig wlp3s0 essid ‘HotelWifi’ key ‘password’ dhclient wlp3s0 if wifi has no password set wpa_passphrase will complain and thus can […]
Hardware Assembly: (i think 512MByte should be enough, 1GByte probably pretty good) Software Installation: including squid-proxy and web advertisement-filtering in the next part: OpenVPN 🙂 Thanks man! Amazing tutorials! by https://internetz.me Related Links: https://www.howtoforge.com/pfsense-squid-squidguard-traffic-shaping-tutorial http://www.shallalist.de/Downloads/shallalist.tar.gz
ip address add 192.168.100.200/24 dev eth0 will add ip 192.168.100.200 to your eth0 / LAN, in case you need to access more subnets than the default DHCP-subnet. please also checkout this amazingly cool youtube video tutorial on how to build […]
FOR SECURITY REASONS, KEEP ROUTER FIRMWARE UPDATED! Freifunk updates its router firmware and closes a critical security vulnerability that could allow attackers to install their own firmware on the devices. (src: heise.de) welcher router/welche hardware verwenden/zukunftstauglich? (ändert sich von Jahr […]
http://mirror.switch.ch/ftp/mirror/zeroshell/ZeroShell-3.6.0.iso -> fire this up in a VirtualBox machine… using “Generic Linux” settings. explanation later. as seen on: http://www.pcwelt.de/ratgeber/DSL-Optimierung_-_So_tunen_Sie_Ihr_Netzwerk-Multi-WAN_und_Co.-8913906.html Firewall Router Zeroshell is a Linux distribution for servers and embedded devices aimed at providing the main network services a LAN […]
IPv6 is great for everything that is (more or less) DIRECTLY connected to the internet (needs a public accessible address): firewalls / routers modems servers (using firewalls / routers and modems to connect) but it seems completely “overkill” and even […]
ifconfig shall be replaced by “ip” but many users are very used to ifconfig 🙂 is not anymore installed per default, and needs to be installed manually. the problem: ifconfig might not be sufficient anymore, because it might for example, not […]
A simple example, assuming your primary network interface is eth0 and has an ip of 192.168.1.1 and the new ip is 192.168.1.2: auto eth0 iface eth0 inet static address 192.168.1.1 netmask 255.255.255.0 gateway 192.168.1.254 auto eth0:0 iface eth0:0 inet static […]
#install software # CentOS7 yum update && yum install samba-client samba-common cifs-utils # Debian hostnamectl; # tested on (server + client) Operating System: Debian GNU/Linux 12 (bookworm) Kernel: Linux 6.1.0-18-amd64 Architecture: x86-64 # and older # (GNU) Linux Debian […]
what service/program is using what port: # list all open ports and listening services/programs lsof -i -P -n; web gui based -> https://dwaves.de/2018/04/04/monitoring-your-network/ watch traffic on terminal -> https://dwaves.de/2017/06/20/linux-bash-terminal-monitor-watch-network-traffic-in-real-time/ resource monitoring -> https://dwaves.de/2017/07/17/debian9-stretch-basic-web-based-ressource-monitoring-with-basic collectd/ nmap returns a nice overview… but […]
Creditz: Linode orginal article: https://www.linode.com/docs/tools-reference/tools/limiting-access-with-sftp-jails-on-debian-and-ubuntu Did you know SFTP has NOTHING to do with FTP 🙂 You do not need a complicated ssl-ftp-server-setup to provide encrypted up and downloads… no you only need an ssh-server, that you probably have installed […]
setting dynamic and fixed ips from bash-terminal – when given care to detail – is working just fine. there are also more or less working network-manager guis. mixing both is not recommended any network-manager gui software should respect the manual […]
rsync is a neat utility that lets you transfer whole directories ssh-encrypted over the internet. So it is perfect for online-backup purposes off servers etc. pp. It even can do partial-transfer which means: if 1 bit changed in a 1TB […]