Ping prohibited in Linux

1. modify the configuration file to take effect temporarily for the system. The setting does not take effect after the system is restarted.
[Root @ 208 ~] # Echo "1">/proc/sys/net/ipv4/icmp_echo_ignore_all

2. Change the system configuration file permanently.
[Root @ 208 ~] # Vim/etc/sysctl. conf
Net. ipv4.icmp _ echo_ignore_all = 1 -- add this row
[Root @ 208 ~] # Sysctl-p
Net. ipv4.ip _ forward = 0
Net. ipv4.conf. default. rp_filter = 1
Net. ipv4.conf. default. accept_source_route = 0
Kernel. sysrq = 0
Kernel. core_uses_pid = 1
Net. ipv4.tcp _ syncookies = 1
Net. bridge. bridge-nf-call-ip6tables = 0
Net. bridge. bridge-nf-call-iptables = 0
Net. bridge. bridge-nf-call-arptables = 0
Net. ipv4.icmp _ echo_ignore_all = 1
Net. ipv4.conf. all. arp_policy = 1

3. handle errors when they take effect
[Root @ 208 ~] # Sysctl-p
Net. ipv4.ip _ forward = 0
Net. ipv4.conf. default. rp_filter = 1
Net. ipv4.conf. default. accept_source_route = 0
Kernel. sysrq = 0
Kernel. core_uses_pid = 1
Net. ipv4.tcp _ syncookies = 1
Error: "net. bridge. bridge-nf-call-ip6tables" is an unknown key -- error message
Error: "net. bridge. bridge-nf-call-iptables" is an unknown key
Error: "net. bridge. bridge-nf-call-arptables" is an unknown key
Net. ipv4.icmp _ echo_ignore_all = 1
Net. ipv4.conf. all. arp_policy = 1

Solution:
[Root @ 208 ~] # Modprobe bridge
[Root @ 208 ~] # Lsmod | grep bridge
Bridge 83177 0
STPs 2218 1 bridge
Llc 5546 2 bridge, stp

Recommended reading:

Installation of arping under Fedora 18

Install smokeping in CentOS 6.2 to test network conditions

Iptables ping configuration in CentOS

How to ping Windows in VMware Linux

In Linux, ping the network for a long time, add a timestamp, and record the timestamp to the text.