如果出现bash:./vmware-install.pl :/usr/bin/perl:bad interpreter:No such file or directory.现象，输入yum groupinstall "Perl Support"即可。

If you have configured in Asterisk (or you fron-end FreePBX) sip trunk provider of VoIP, but outbound link is not working, and in output:# asterisk -rx "sip show peers"you see that your sip trunk UNREACHABLE in the

使用 telnet 测试现有监听端口连通性 可以使用 Linux 自带的 telnet 工具来测试现有端口的连通性，测试命令为： telnet <host> <port># host 是目标服务器 IP，port是待测试端口号示例： 可以如下指令测试 22 端口的连通性： telnet 127.

环境：CentOS Linux release 7.6.1810 (Core) ；1.查看当前默认启动内核[inspur@localhost ~]$ grub2-editenv list grub2-editenv: error: cannot open `/boot/grub2/grubenv.new': Permission denied. [inspur@localhost ~]

（服务器用的阿里云主机，CentOS 7.3，似乎不管内存多少阿里云都把 conntrack_max 设成 65536）症状CentOS服务器，负载正常，但请求大量超时，服务器／应用访问日志看不到相关请求记录。在dmesg或/var/log/messages看到大量以下记录：kernel: nf_conntrack: table full, dropping packet.原因服务器访问量大，内核netfilter模块conntrack相关参数配置不合理，导致新连接被drop掉。详细nf_con

"ERROR: Failed to load nf_conntrack module: modprobe: ERROR: could not find module by name='nf_conntrack'..." was exactly the error I had after the upgrade to firewalld-0.6.3-2.el7_7.1.noarch.You should check if the downgrade w

OEM SLP Key Windows Server 2012 R2 Datacenter =====================   2N9T6-Y284D-T68G9-QGV6X-FRFTD --- 00253-00000-00014-AAOEM --- Dell   Code:   Windows Server 2012 R

tcpdump -s0 -i any tcp port 80 -w test.pcapnetstat -anp | grep 192.**.**.107 tcpdump  -i any tcp port 80 -qnetstat -anpc |grep ":80"netstat -anpc |grep 192.**.**.107lsof | grep watchdogstat /usr/sbin/watchdog[root@jiradbslave sbin