Linux Network Settings

For Linux 6.8, 6.10, 7.3, 7.6, 7.8 or 7.9, use the following guidelines to apply the appropriate settings based on the size of your system:

Small system: 64 GB RAM or less
Medium system: 64 GB to 128 GB RAM
Large system: Greater than 128 GB RAM

Specify settings in the file /etc/sysctl.conf.

Network Settings - Small System

Specify the following for a system consisting of 64 GB RAM or less:

# Controls IP packet forwarding
net.ipv4.ip_forward = 0

# Controls source route verification
net.ipv4.conf.default.rp_filter = 1
 
# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0
 
# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0
 
# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1
 
# Controls the use of TCP syncookies
net.ipv4.tcp_syncookies = 0
 
# Controls the default maxmimum size of a mesage queue
kernel.msgmnb = 65536
 
# Controls the maximum size of a message, in bytes
kernel.msgmax = 65536
 
# Controls the maximum number of shared memory in bytes
kernel.shmmax = 429494272
 
# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 104857

Network Settings - Medium System

Specify the following for a system consisting of 64 GB to 128 GB RAM:

# Controls IP packet forwarding
net.ipv4.ip_forward = 0
 
# Controls source route verification
net.ipv4.conf.default.rp_filter = 1
 
# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0
 
# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0
 
# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1
 
# Controls the use of TCP syncookies
net.ipv4.tcp_syncookies = 0
 
# Controls the default maxmimum size of a mesage queue
kernel.msgmnb = 65536
 
# Controls the maximum size of a message, in bytes
kernel.msgmax = 65536
 
# Controls the maximum number of shared memory in bytes
kernel.shmmax = 8589934592
 
# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 2097152

Network Settings - Large System

Specify the following for a system consisting of greater than 128 GB RAM:

# Controls IP packet forwarding
net.ipv4.ip_forward = 0
 
# Controls source route verification
net.ipv4.conf.default.rp_filter = 1
 
# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0
 
# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0
 
# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1
 
# Controls the use of TCP syncookies
net.ipv4.tcp_syncookies = 0
 
# Controls the default maxmimum size of a mesage queue
kernel.msgmnb = 65536
 
# Controls the maximum size of a message, in bytes
kernel.msgmax = 65536
 
# Controls the maximum number of shared memory in bytes
kernel.shmmax = 17179869184
 
# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 4194304