February 5, 2016
February 5, 2016
General Switch commands
Network,Switch Commands Initial configuration of Switch1 with ip 172.16.10.16 >en #config t (config)#enable password cisco (config)#enable secret cisco (config)#hostname India-switch1 (config)#ip address 172.16.10.16 255.255.255.0 (config)#ip default-gateway 172.16.10.1 (config)#int f0/1 (config-if)#description Finance (config-if)#int f0/26 (config-if)#description Trunk (config-if)#exit (config)# Initial Configuration of 2950 Switch with ip 172.16.10.17 255.255.255.0 >en #config t (config)#hostame India-switch2 (config)#enable password cisco (config)#enable…
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February 5, 2016
General Router Commands
Network,Router Modes: Router> User mode Router# Privilege mode Router(config)# Configuration mode Router(config-if)# Interface configuration mode Router(config-subif) Sub Interface configuration mode Router(config-line)# Line mode Router(config-router)# Router configuration mode Global configuration mode in detail: Router> Can see Router config, but cannot change any settings Router# Can see Router config and move to config make changes Router#conf t…
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January 8, 2016
Network Installation on Linux using NFS
Linux General,The following package must be installed tftp , tftp server dhcp nfs Configure Dhcp Install dhcp,copy /usr/share/doc/dhcp-xxxx/dhcpd.conf.sample to /etc/dhcp/dhcpd.conf cp -r /usr/share/doc/dhcp-xxxx/dhcpd.conf.sample /etc/dhcp/dhcpd.conf vi dhcpd.conf option domain-name “your domain name”; option domain-name-servers YOUR-SERVER ; default-lease-time 600; max-lease-time 7200; allow bootp; allow booting; ignore client-updates; ddns-update-style none; not authoritative; log-facility local7; subnet YOUR-NETWORK netmask 255.255.255.0 {…
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September 23, 2015
Open VPN Server Configuration on Linux
Linux General,Install Open VPN RPM. Dependencies openssl lzo pkcs11-helper Download openvpn-<version>.rpm , And install using this command rpm -ivh openvpn-<version>.rpm It will create folder under /etc/openvpn and /usr/share/doc/openvpn-2.1.1 cp -r /usr/share/doc/openvpn-<version>/easy-rsa /etc/openvpn cp -r /usr/share/doc/openvpn-<version>/sample-config-files/server.conf /etc/openvpn we have to copy the “easy-rsa” folder and “server.conf” file from /user/share/doc/openvpn-<version>… to…. /etc/openvpn Then go to /etc/openvpn cd /etc/openvpn…
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September 12, 2015
Networking Concepts, in RHEL 7 or CENTOS7.
Linux General,Let’s see the networking concepts, in RHEL 7 or CENTOS7. You should concentrate on these if servers upgrade: We usually edit the network configuration file in the older versions to manage IPs. under /etc/sysconfig/network-scripts/ In the new version no more editing is required. We can add, modify, delete the IPs using the tool called NMCLI…
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August 26, 2015
Symbolic link hack and its prevention in cPanel based servers.
Linux General,Symbolic link: Just like we use shortcut in windows based operating system. Symbolic link (symlink or soft link) is a shortcut like file in linux operating systems. In linux a normal user cannot access server main/root directory. So, they use this symlink option as a tool to hack/gain access to server main/root directory. User will…
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August 14, 2015
DNS Configuration (Internal and External)
Linux General,The following package must be installed : bind-9.8.2-0.17.rc1.el6_4.6.i686.rpm bind-chroot-9.8.2-0.17.rc1.el6_4.6.i686.rpm bind-utils-9.8.2-0.17.rc1.el6_4.6.i686.rpm bind-libs-9.8.2-0.17.rc1.el6_4.6.i686.rpm Install DNS: Install bind and bind-chroot package using bellow command rpm -ivh bind-9.8.2-0.17.rc1.el6_4.6.i686.rpm rpm -ivh bind-chroot-9.8.2-0.17.rc1.el6_4.6.i686.rpm rpm -ivh bind-utils-9.8.2-0.17.rc1.el6_4.6.i686.rpm rpm -ivh bind-libs-9.8.2-0.17.rc1.el6_4.6.i686.rpm Create DNS key using below format: % dnssec-keygen -a hmac-md5 -b 128 -n USER dhcpupdate Kdhcpupdate.+157+14638 This will create a 128bit…
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July 13, 2015
Routing Basics
CCNA workbook,Routers in a network discover remote networks in two ways Statically configured routes Dynamic routing protocols By default routers knows only the directly connected networks represented by “C” Static Routing Static route are mainly used when routing from a particular network to a stub network. Stub networks are the networks that can be accessed through…
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July 8, 2015
Routers Basics
CCNA workbook,ROUTERS: It is an internetworking component that connects networks at different geographical locations.It has Serial Port Auxillary Port Console Port AUI (Attachment Unit Interface) or Ethernet(which uses RJ45 port) Routers are of two types Fixed -fixed number of slots (series from 700 to 2500, exception 1750, 1751) Modular – Upgradable slots and ports (series from…
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