NFS Firewall Rumi, September 9, 2015 Dynamic ports cannot be protected by port filtering firewalls such as iptables. First, you need to configure NFS services to use fixed ports. Open /etc/sysconfig/nfs, enter: # vi /etc/sysconfig/nfs Modify config directive as follows to set TCP/UDP unused ports: # TCP port rpc.lockd should listen on. LOCKD_TCPPORT=lockd-port-number # UDP port… Continue Reading
NFS Server and Client on CentOS Rumi, September 9, 2015 Assumptions: NFS Server IP: 172.16.5.100 NFS Client Node1: 172.16.5.101 NFS Client Node2: 172.16.5.102 NFS Client Node3: 172.16.5.103 NFS Client Node4: 172.16.5.104 On the NFS Server & All Client machine as well: yum install nfs-utils nfs-utils-lib Edit the exports file that shows what to share and with whom. So run: Continue Reading
Enable mod_rewrite on Apache for Debian Rumi, September 8, 2015 To enable and load mod_rewrite, do the following. $ sudo a2enmod rewrite Then open up the following file, and replace every occurrence of “AllowOverride None” with “AllowOverride all”. $ sudo vi /etc/apache2/sites-available/default or $ sudo vi /etc/apache2/sites-available/000-default Finally, restart Apache2. $ sudo service apache2 restart Continue Reading
NMAP Security Scanner on Linux Rumi, August 21, 2015February 11, 2017 First of all, you should get the “nmap” package installed in your system. On CentOS yum install nmap On Debian apt-get install nmap On Ubuntu sudo apt-get install nmap NMAP Commands: sudo nmap -sS [IP address] or [website address] sudo nmap -O –osscan-guess [IP address] or [website address] sudo nmap… Continue Reading
PEN: HTTP Load Balancer Rumi, August 15, 2015August 15, 2015 This is performed on a CentOS 6.x 64 bit machine Install pen which is lightweight simple Load Balancing software. It is TCP protocol based, so it’s possible to balance not only HTTP but SMTP, FTP, LDAP and so on. This example is based on the environment like follows. Configure Pen… Continue Reading
perl(Net::SSLeay) is needed by webmin Rumi, July 16, 2015 So the Webmin on Redhat/CentOS is now requiring this particular perl module to be pre-installed before the RPM installer begins. A very short cut to install this module by using yum- yum install -y perl-Net-SSLeay Voila! your done. Continue Reading
Zimbra Domain Administration (Multi-tenant) Rumi, June 4, 2015 In order to create a multi tenancy in zimbra OSA, can be acheived through a bash script below. Thanks to Ahmad Imanuddin (http://www.imanudin.com) for sharing this very useful script. cd /srv/ vi admin-delegate.sh Fill with the following line : Continue Reading
Zimbra Increasing Attachment Size works for 8.5 Rumi, June 4, 2015 Through zimbraGUI didn’t find it how to do it, but through console it appeared to be working with the following set of commands to modify postfix actually- su zimbra zmprov mcf zimbraMtaMaxMessageSize 20971520 zmprov mcf zimbraFileUploadMaxSize 20971520 zmprov mcf zimbraMailContentMaxSize 52428800 zmprov modifyConfig zimbraMtaMaxMessageSize 52428800 postfix reload Once theyre executed,… Continue Reading
Two Default Gateways on One System Rumi, May 21, 2015 Problem Description You have built two or more network cards into one Linux system and each of these cards has its own default gateway. By default, you can only have one default gateway on a system. The case described would lead to asynchronous routing, whereby the router would reject the… Continue Reading
2 Gateways or Multiple Gateway on a single CentOS box Rumi, May 21, 2015 Scenerio- eth0- 172.30.0.100 | Gateway- 172.30.0.97 eth1- 192.168.2.247 | Gateway- 192.168.2.1 Need to connect to SIP BOX destination (fictitious)- 202.140.1.1 eth0 has not internet access but it uses the mentioned (172.30.0.97) as gateway to reach 202.140.1.1 server eth0 has internet access by using 192.168.2.1 gateway. Here goes the configuration on /etc/sysconfig/network-scripts/ifcfg-eth0 Continue Reading