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Linux 17 - Create Partitions and Filesystems

Jul 28, 2012 · 4 min read · commands linux

partitioncreate filesystemsmake swap space There are two types of partitions on a block device - primary - extended fdisk Partition table manipulator for Linux fdisk -lList the partition tables for the specified devices and then exit. If no devices are given, those mentioned in /proc/partition…

Linux 16 - Basic File editing with VI

Jul 14, 2012 · 1 min read · commands linux

VI - press I to insert- press O to insert to next line - press :! command to execute a command inside VI- enter numbers and then dd to delete lines - for intance to delete 17 lines type 17 in command mode and then dd- to delete characters instead of dd type x- yy copies the line- A inserts after the …

Linux 14 - Process Priorites

Jun 9, 2012 · 3 min read · commands linux

niceness explained ps pstree htop nice renice niceExecute programs at a specified priority levelThis allows you to control which processes the kernel should favor when dividing processor time among running programs. Processes with the lowest nice number are executed with the highest priority and vice versa.On most sys…

Linux 13 - Create, Monitor and Kill Processes

Jun 2, 2012 · 2 min read · commands linux

background and foreground persistent processes interact with processes sort running processes in top Background and Foreground# sleep 1000 captures the terminal and sleeps for 1000 sec to run in bacground add & to the end this wil give back control of terminal to access programs from background use jobs commands t…

Linux 12 - Streams, Pipes and Redirects

May 26, 2012 · 1 min read · commands linux

- stdin - stdout - stderr - tee - xargs stdin stuff a program chews up wc < file1.txtsome programs don’t accept data from stdin stdoutstuff a program spits out ls > ls.txt ls 1> ls.txt stderrwhere a program complains ls bob 2> ls.txtredirects stderr to ls.txt Both stdout and stderror go to the conso…

Linux 11 - Basic File Management

May 5, 2012 · 3 min read · commands linux

copy, move, delete wildcards find files based on type, size & date tar, cpio, dd bzip2, gunzip copy - cp - cp -R; -r; --recursive example: - cp 123.txt 234.txt - cp -R folder1/ folder2/ move - mv example: - mv folder1/ folder2/ - mv folder1/789.txt ./ delete / remove - rm - rm -f - rm -rf example: - rm file.abc - …

Linux 9 - Working the Command Line

Apr 14, 2012 · 4 min read · configure commands linux info

Bash Shell environment PATH environment variables history completion commands The shell that a user uses is defines in /etc/passwd testuser:x:1001:1001:testuser user:/home/testuser:/bin/bash The settings for how bash behaves are stored in a couple different places /etc/profile# /etc/profile: system-wide .profile file …

Linux 8 - RPM and yum package management

Apr 3, 2012 · 9 min read · configure centos commands linux

rpm rpm2cpio alien yum /etc/yum.conf /etc/yum.repos.d yum downloader yum is alike like apt-get is in debian like distribsyum install open-ssh clients[root@localhost ovidiu]# yum install openssh-clients Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: mirrors.ch-center.com * extras: mirr…

Linux 5 - The Boot Manager

Mar 18, 2012 · 2 min read · linux debian configure commands centos info

LILO GRUB BackUP the MBR LILO is rarely used the LILO configuration is stored in /etc/lilo.conf Explanation: –boot → what device it’s going to boot from (in this case the first serialATA –map → LILO creates a map file to say what is mapped where –install → default, leave this boot.b as the default –prompt → does it pr…

Linux 4 – Hard Disk Layout

Mar 15, 2012 · 2 min read · configure commands linux info

Partitons and Disk Filesystems mount points swap space design considerations Important folders in Linux/boot → (about 100MB+ is fine) for kernel, initrdcan not be read if software raid is present/home → user related folders & files, configuration files, etc/etc → configuration files, system wide/root → root’s home…

Linux 3 - Runlevels and Rebooting

Mar 13, 2012 · 5 min read · commands linux

runlevels inittab init.d init / telinit reboot shutdown upstart Runlevels: Runlevel Info More Info 0 HALT Standard acrosss all distributions 1 Single User Mode (recovery) no network, root access, no password to login, standard across all distributions 2 Debian/Ubuntu Default mode for both X and text mode 3 RedHat/SuSE…

Basic IPv4 / IPv6 Routing

Nov 20, 2011 · 2 min read · routing protocol routes configure cisco commands

During your career as a Cisco network engineer you will have to deal understanding IPv6 address structure. So in this lab scenario you will learn to configure IPv4 and IPv6 networks on two routers then using RIP routing protocol you will configure WAN connectivity between. This lab has been created using …

CDP

Sep 1, 2011 · 3 min read · ccna 2 gns3 configure basic cisco cdp commands info

Cisco Discovery Protocol - bun pentru obtinerea informatiilor de la alte routere sau swtich-uri direct conectate. - se trimit mesaje periodice (60s) - default pornit - contin informatii de genul: - tipul de device - interfetele cu care au legaturi - versiuni ale IOS - modelul device-ului Poate fi folosit ca un tool pe…

Configurare topologie simpla GNS3 partea a 2-a

Aug 31, 2011 · 6 min read · wireshark routes ccna 2 gns3 routing protocol configure basic protocols cisco part 2 commands

Continuarea configurarilor din topologia anterioara Obiective: Salvarea configuratilor (Topologie, Routere, PC-uri) Configurarea interfetei seriale de pe R2 Configurarea interfetei ethernet de pe R2 Altele Captura traficului prin Wireshark Salvarea configuratiilor Preambul: Routere/Switch-uri #copy running-confi…

Configurare topologie simpla GNS3

Aug 30, 2011 · 6 min read · routes ccna 2 linux routing protocol router hardware configure basic cisco commands

Topologie CCNA 2 3 routere 2 switch-uri simple 3 PC-uri Configurare adrese IP pentru host-uri sudo suhostname [nume]ifconfig eth0ifconfig eth0 <IP> netmask <NM> uproute add default gw <GW> eth0 Configurarea consolei si a liniilor virtuale VTY R1(config)#line console 0R1(config-line)#password ciscoR1(…

Network Security

Jul 10, 2011 · 6 min read · ccna 4 security SSH basic cisco commands info

Why is security important ? If the security of the network is compromised there could be seroious consequences such as: loss of privacy theft of information legal liabity As time went on, and attackers' methods and tools improved, attackers no longer required the same level of sophisticated knowledge. Common terms for…

Port security

Feb 27, 2011 · 4 min read · ccna 3 port security configure switchport cisco commands

Securitatea la switch de nivelul de tip acces a) Port security b) port protected c) Port blocked d) Acces la switch fara parola e) Storm control a) Default nu e pornit Port Security Tipuri de atacuri oprite de Port Security - MAC address spoofing - schimbarea MAC-ului asignat de vendor cu un altul - Se aplica doar pen…

OSPF

Feb 6, 2011 · 10 min read · ccna 2 routing protocol configure basic ospf commands info

Open Shortest Path First protocol de rutare link state direct competitor pentru EIGRP (proprietar CISCO) Protocol de rutare classless Scalabil prin folosirea de zone Metrica valoare arbitrara denumita cost CISCO IOS foloseste bandwidth administrativ in calculul metricii Avantaje Convergenta mai rapida decat RIP (excep…

Verifying Basic Router Configuration

Dec 22, 2010 · 5 min read · troubleshoot ccna 2 cisco commands

These commands are for viewing and debugging the configuration #show running-config This command displays the current running configuration that is stored in RAM. With a few exceptions, all configuration commands that were used will be entered into the running-config and implemented immediately by the IOS. R2#show run…

Configuring a router

Dec 5, 2010 · 3 min read · ccna 2 configure basic cisco commands

Basic Router Configuration When configuring a router, certain basic tasks are performed including: Naming the router Setting passwords Configuring interfaces Configuring a banner Saving changes on a router Verifying basic configuration and router operations The first prompt appears at user mode. User mode allows you t…