TCP Traffic Regulation (TR), introduced in IBM AIX 6.1 TL2, provides centralized port-based regulation of TCP connection resource utilization. TCP firewall profiles, customized by a security administrator, can now be loaded into the AIX kernel for active mitigation of TCP-based Denial-of-Service (DoS) attacks.

The traffic regulation limit the number of simultaneous connection for a user. It's specify by port or port range.

To show the limits defined:

[root@labotest]/root # tcptr -show 
TCP Traffic Regulation Policies: 
StartPort=1 EndPort=12 MaxPool=256 Div=1 Used=0 
StartPort=13 EndPort=13 MaxPool=256 Div=1 Used=0 
StartPort=14 EndPort=20 MaxPool=256 Div=1 Used=0 
StartPort=21 EndPort=21 MaxPool=256 Div=1 Used=0 
StartPort=22 EndPort=25 MaxPool=256 Div=1 Used=4 
StartPort=26 EndPort=36 MaxPool=256 Div=1 Used=0 
StartPort=37 EndPort=37 MaxPool=256 Div=1 Used=0 
StartPort=38 EndPort=110 MaxPool=512 Div=1 Used=0 
StartPort=111 EndPort=111 MaxPool=256 Div=1 Used=0 
StartPort=112 EndPort=9089 MaxPool=512 Div=1 Used=512 
StartPort=9090 EndPort=9090 MaxPool=10 Div=3 Used=0 
StartPort=9091 EndPort=65535 MaxPool=512 Div=1 Used=0 

With no rules defined:

[root@labotest]/root # tcptr -show 
No policy defined. 

To disable Traffic regulation: For each rule, delete it with the follwing command: tcptr -delete <StartPort> <EndPort>

[root@labotest]/root # tcptr -delete 1 12

Change the no parameter, to fully disable traffic regulation:

[root@labotest]/root # no -p -o tcptr_enable=0