On RHEL6 and RHEL7 once you add a second interface on the same subnet, it does not work ( no ping) The cause of the problem is a change on the parameter rp_filter vi /etc/sysctl.conf net.ipv4.conf.default.rp_filter = 2 net.ipv4.conf.all.rp_filter = […]
CentOS7 change interface name
In CentOS7 or RedHat7 again we have funky strange network interfaces names… To change the name back to eth0 just follow: 1. Rename the device name vi /etc/sysconfig/network-scripts/ifcfg-ens** 2. Rename the file mv /etc/sysconfig/network-scripts/ifcfg-ens192 /etc/sysconfig/network-scripts/ifcfg-eth0 3. add net.ifnames=0 biosdevname=0 to […]
Linux network tools
This is a small list of some really nice linux tools I recommend every sysadmin to have somewhere. dstat Combines vmstat, iostat, ifstat, netstat information and more http://dag.wieers.com/home-made/dstat/#documentation vnstat The best to monitor how much data was transfered tx/rxhttp://humdi.net/vnstat/ iftop […]
How to Install iftop
How to Install iftop on RedHat 6 64 bits, CentOS. iftop is a very very cool tool. It displays what connections are made and their usage etc… Script to Install #!/bin/bash #Install iftop RedHat 6 #by Felipe Ferreira http://felipeferreira.net:81conf July/2011 […]
ESX VLAN TAGGING
VLAN testing in ESX 4, So I need to test lots of VLANs and make sure connectivity is OK. Well here is quick and easy way to do it? 1. Create a port group on the vSwitch with ID 4095. […]
nlb load balance linux
Load balancing can help with almost any kind of service, including HTTP, DNS, FTP, POP/IMAP, RDP and SMTP. There are a number of open source load balancing applications, but one simple command-line load balancer, balance, remains one of the most […]
Linux Better Network Manager
I finally found a better product that default netowkr-manger gnome (the one that comes with ubuntu) Its name is wicd-client and its way better check it out at: http://wicd.sourceforge.net/download.php How to install wicd # echo “deb http://apt.wicd.net hardy extras” >> […]