#Security

How KVM Isolates Guest Virtual Machines from the Host The Core Problem: Running Multiple Kernels Safely VMX Root vs Non-Root Mode: The Key Mechanism VMX Root Mode VMX Non-Root Mode What Happens When a Guest Tries Something Privileged? Memory Isolation: Why Guests Can’t See Host RAM Devices and the Host OS Boundary Why This Matters Takeaway How KVM Isolates Guest Virtual Machines from the Host Virtual machine isolation is the foundation of secure virtualization. [Read More]

Introduction Prerequisitess Install Google’s PAM Intialization Configuring PAM Configuring OpenSSH Making SSH Aware of MFA Introduction One of the secure login method in linux based system is Key Based Authentication. Key authentication provides cryptographic strength that even extremely long passwords can not offer. With SSH, public key authentication improves security considerably as it frees the users from remembering complicated passwords (or worse yet, writing them down). User has private key in his laptop / desktop and public key will be pushed to destination server. [Read More]

Preface A major problem facing by mail server admin is DOS (Deniel Of Service) attack. Hackers will try to mess up with the most popular ports of a UNIX/LINUX machines. We can prevent this my writing an IPTABLE rule in the server. The working is ,if some one is trying make connection continuously through a specified port the rule will block the IPADDRESS permanently. Here I am stating the securing of PORT 25 (SMTP) here you can use your own [Read More]