服务器评测
1.修改配置文件对系统临时生效，系统重启后设置不起作用。
[root@208 ~]# echo “1” > /proc/sys/net/ipv4/icmp_echo_ignore_all
2.永久生效，修改系统的配置文件
[root@208 ~]# vim /etc/sysctl.conf
net.ipv4.icmp_echo_ignore_all = 1 –添加这一行
[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_notify = 1
3.如果生效时有错误，错误处理
[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 –错误信息
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_notify = 1
解决方法:
[root@208 ~]# modprobe bridge
[root@208 ~]# lsmod | grep bridge
bridge 83177 0
stp 2218 1 bridge
llc 5546 2 bridge,stp
推荐阅读：
Fedora 18 下arping 的安装 http://www.linuxidc.com/Linux/2013-06/85300.htm
CentOS 6.2 下安装 smokeping 测试网络状况 http://www.linuxidc.com/Linux/2012-12/75843.htm
CentOS中Iptables关于ping的配置问题 http://www.linuxidc.com/Linux/2012-11/74660.htm
VMware下Linux如何ping通Windows http://www.linuxidc.com/Linux/2012-11/73749.htm
Linux下长时间ping网络加时间戳并记录到文本 http://www.linuxidc.com/Linux/2012-09/70440.htm
