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  • What is iptables? How to manage iptables?

    Posted at January 28, 2017 at 11:39 am by Jithin

    You should take security very important if you own a web application. Customers will not like to continue with a service where they can't get good security. If you have a shared hosting account, there are limitations to the options you can customize for security. If you are owner of a server like a VPS, quick server, dedicated server, you can customize the server according to your needs as the server is yours and you have  full control over your website. There are many ways to configure a serve   [...]

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    Managing Rich Rules in Firewalld

    Posted at January 5, 2017 at 4:26 pm by Jithin

    Apart from the regular zones and services syntax that firewalld offers, administrators have two other options for adding firewall rules: direct rules and rich rules.   Direct rules Direct rules allow an administrator to insert hand-coded { ip, ip6,eb} tables rules into the zones managed by firewalld. While powerful, and exposing features of the kernel netfilter subsystem not exposed through other means, these rules can be hard to manage. Direct rules also offer less flexibility tha   [...]

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    Linux Network Address Translation (NAT)

    Posted at January 5, 2017 at 4:25 pm by Jithin

    Firewalld supports two types of Network Address translation(NAT): masquerading and port forwarding. Both can be configured on a basic level with regular firewall-cmd rules, and more advanced forwarding configurations can be accomplished with rich rules. Both forms of NAT modify certain aspects of a packet, like the source or destination, before sending it on.   Masquerading With masquerading, a system will forward packets that are not directly addressed to itself to the intended re   [...]

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    Manage and Configure Linux FirewallD ( firewall-cmd )

    Posted at November 29, 2016 at 1:50 pm by Jithin

    FirewallD is the default method in Rhel7 for managing host-level firewalls. Started from the firewalld.service, firewalld manages the Linux kernel net filter subsystem using the low-level iptables, ip6tables, and ebtables commands. FirewallD separates all incoming traffic into zones, with each zone having its own set of rules. To check which zone to use for an incoming connection, firewalld uses the logic, where the first rule that matches wins: 1) If the source address of an incoming packet    [...]

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