Category Archives: Linux

NIC loads issue from restored VM


Issue: when try to restore Linux VM (or physical machine with dissimilar NIC) from another host ESX server, guest (VM) server NIC card may not be activated due to mismatch of network card MAC address in destination host. Following error … Continue reading

Posted in Linux, VMWare | Tagged

Install openNMS


Following steps applies to: Red Hat Enterprise Linux 5 Red Hat Enterprise Linux 6 CentOS 5 CentOS 6 OpenNMS 1.8 OpenNMS 1.9 OpenNMS 1.10.1 (stable) Install portgresql-server: #yum install postgresql-server -y Initiate the database: #service postgresql initdb Configure PostgreSQL: Edit … Continue reading

Posted in Linux, Others | Tagged

Clear ARP entries from various devices


From Cisco Switches / Firewall (ASA) / Switches: To see the arp table: #show arp To clear the arp table: #clear arp To clear selective entry: #clear ip arp IPAddress eg. clear ip arp 192.168.2.109 Windows: c:\> arp -a (display … Continue reading

Posted in Cisco, Linux, Windows | Tagged | 1 Comment

Change default SSH port


step1. #vi /etc/ssh/sshd_config step2. #Port 22022 (22022 defineed as custom port but you can put any number)step3: #/etc/init.d/ssh restart  (restart SSH) Step4: ssh username@hostname.com -p 22022 (verify that is is working) (#ssh -p 22022 hostname) (bind to listed particular address … Continue reading

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Apache configuration


Install Apache rpm file (from Linux installation DVD) #rpm -ivh httpd-2.0.48-1.2.rpm Apache to start at boot. #chkconfig httpd on (may use #setup for text base GUI) Start Apache service #/etc/rc.d/init.d/httpd start Re Start Apache service (Start and Stop) #/etc/rc.d/init.d/httpd restart … Continue reading

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Few Linux commands for novice net-admin


Adding IP, netmask and default gateway to Linux machine (note: configuration file path can be vary depending on the Linux flavor as listed below) # ifconfig eth0 192.168.2.10 netmask 255.255.255.0 up (eth0 is a 1st network card adapter interface. eg. … Continue reading

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Backup your Linux server


I have been using #rsync for very long and it woks always well for remote backup or local data backup. You can put following syntax on Cron job to backup your home directory to the another hard disk (internal) #rsync … Continue reading

Posted in Linux | Tagged