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Configuring IP Dynamic Port Ranges

As you are probably aware, IP port numbers are 16 bit unsigned integers in the range 0 to 65535. IANA (Internet Assigned Numbers Authority) manages these port numbers. See the IANA Service Name and Transport Protocol Port Number Registry for more information. IANA specifies the range 49152 to 65535 be used for dynamic (AKA private) ports. From the above referenced document: Port numbers are assigned in various ways, based on three ranges: System Ports (0-1023), User Ports (1024-49151), and the Dynamic and/or Private Ports (49152-65535); the difference uses of these ranges is described in RFC6335. System Ports are assigned by

Address Space Layout Randomization in Linux

Address Space Layout Randomization (ASLR) was first implemented in Linux in 2001 and formally included in Linux kernel 2.6.12 in 2005. Microsoft followed soon afterwards and implemented ASLR in Vista in 2007. ASLR randomizes process memory address space in order to prevent an attacker from finding the addresses of functions or ROP (Return Oriented Programming) gadgets required to successfully complete an exploit. The effectiveness of ASLR is limited by the amount of available entropy which varies from platform to platform depending on the implementation. For ASLR to be useful, all segments of a processes memory space must be randomized. If