Prevention of Randomization of Well-Known Ports

Feature Summary and Revision History

Summary Data

Applicable Product(s) or Functional Area

All

Applicable Platform(s)

  • ASR 5500

  • VPC-DI

  • VPC-SI

Feature Default

Enabled - Always-on

Related Changes in This Release

Not applicable

Related Documentation

Not Applicable

Revision History


Important

Revision history details are not provided for features introduced before releases 21.2 and N5.1.

Revision Details

Release

With this release, the UP now restricts random source port range from 32768 to 33791.

21.20

First introduced.

Pre 21.2

Feature Changes

Previous Behavior: In releases earlier to 21.20.x, the VPP-based port randomization did not prevent randomizing well-known ports when the source port and destination were different. The allowed port range previously supported was from 1 to 65535.

New Behavior: From this release onwards, the VPP-based port randomization prevents randomizing into well-known ports when the source port and destination are different. The UP now restricts the random source port range from 32768 to 33791.