Category: networking

20.06.2017

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 […]

20.06.2017

with tcpdump you can monitor IP packages, UDP packages, ICMP (ping). zypper install tcpdump; # comes preinstalled in suse12 apt-get install tcpdump; # debian8 yum install tcpdump; # centos7 redhat tcpdump -i eth0 tcpdump -vnni eth0; # very verbose root@Debian8:~# […]

20.06.2017

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; […]

20.06.2017

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
19.06.2017

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 […]

19.06.2017

https://www.ietf.org/rfc/rfc2460.txt (December 1998) Network Working Group, S. Deering (Cisco), R. Hinden (Nokia) https://en.wikipedia.org/wiki/IPv6 larger address space (128 bits, compared with 32 bits in IPv4, allowing 2^128 = 340.282.366.920.938.463.463.374.607.431.770.000.000 devices(addresses) to be registered, while IPv4 allowed only 2^32 = 4.294.967.296 devices […]

19.06.2017

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 […]

03.05.2017

tested and works accross the following systems: uname -a Linux debian 3.16.0-4-686-pae #1 SMP Debian 3.16.39-1+deb8u2 (2017-03-07) i686 GNU/Linux uname -a Linux centos 3.10.0-514.el7.x86_64 #1 SMP Tue Nov 22 16:42:41 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux uname -a Linux suse […]

03.05.2017

You could manually and termporarily get an dynamic ip address from dhcp server like this: dhclient eth0; # renew dhcp lease, ask for dhcp address, where eth0 is probably the nic you want The /etc/sysconfig/network file should contain the following […]

31.01.2017

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

31.01.2017

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 […]

Freifunk
18.01.2017

as seen on: http://dwaves.de/2016/10/22/linux-presentation-tag-ulm/ dieser TP-Link Router ist FreiFunk-Firmware kompatibel: which can be bought bei ebay für 20€ http://www.ebay.de/sch/i.html?_from=R40&_nkw=TL+WR841N&_sacat=0 dieses Model scheint auch kompatibel: http://www.ebay.de/sch/i.html?_from=R40&_nkw=TP-Link+TL-WDR4300+&_sacat=0 koscht aber mehr. Das Konzept: Aktuell besteht das Konzept daraus den Traum „WLAN für Alle […]

16.11.2016

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 […]

19.03.2016

theoretically it should be possible to set a default gateway with ifconfig ifconfig [-a] [-s] [–help] [–version] {interface} [address] [netmask{address}] [gateway{address}] [tftpserver{address} ] [[up] | [down]] Set a fixed ip, activate network card and add default gateway this will: 1. […]

16.06.2015

nmap returns a nice overview… but be aware! nmap localhost will return different results than nmap 192.168.0.123 (actual ip of your host) – because not all services are allowed to be accessed from outside. in the following example smtp and […]

25.09.2013

unfortunately things got changed in debian – but should also be valid throughout Debian 8.X. udev rules, persistent… whatever. why do people have to change stuff that actually works? it seems i am not the only one having this problem: […]