check if port is open

scan, check the host online or not, do not send any message to the destination host, want to know whether the target host is running, and do not want to do other scans, this scanning method is very common)2,-SL (only in the network segment out of the host State, port and other information, query

firewall on and off (effective immediately, fail after reboot): $ sudo service iptables start #开启 $ sudo service iptables stop #关闭 firewall on and off (takes effect after reboot): $ sudo chkconfig iptables on$ sudo chkconfig iptables off To open the relevant port : Modify the/etc/sysconfig/iptables file to add the following: -A input-p tcp-m state--state new-m TCP--dport 22-j ACCEPT After modifying the i

 Vi/etc/sysconfig/iptables-A input-m state–state new-m tcp-p tcp–dport 80-j ACCEPT (allow 80 ports through the firewall)-A input-m state–state new-m tcp-p tcp–dport 3306-j ACCEPT (Allow 3306 ports through the firewall)Special tips:Many netizens add these two rules to the last line of the firewall configuration, causing the firewall to fail to start, the correct one should be added to the default port 22 below the ruleAfter adding the firewall rules

Open the specified port in Linux, and specify the port in linux After tomcat is installed in Linux, the input address http: // ip address on the client cannot be accessed, and port 80 cannot be accessed. The Linux Firewall disables

Tags: netstat TPS state pad extranet Restart making fir inputExample:The steps to open port 10000 are as follows:1, modify the/etc/sysconfig/iptables file, add the following line:-A rh-firewall-1-input-m state--state new-m tcp-p TCP--dport 10000-j ACCEPTRestart IptablesService Iptables Restart2, restart the firewall, there are two ways to restart the firewallA) effective after rebootOpen: Chkconfig iptables

Set the open port of the CentOS firewall and the port of the centos FirewallWhen using CentOS, CentOS firewall sometimes needs to change the settings. The CentOS firewall is enabled by default. You can set the open port of the Cen

This is because you want to use Navicat to connect to the database and find that the connection is notBy looking at a lot of data and testing multiple times to find out because the firewall is not configured with Port 3306Words don't say, open the whole, similarly, 80

SVN open firewall port introduction, svn firewall portPreface Due to the previous laziness, the firewall was shut down after the server was installed with svn. Recently, the server was told to show signs of virus, so the Firewall should be enabled, however, opening the firewall will lead to svn access failure, so now there is a new requirement to

Linux opens port 80 Day client There is a server in the same LAN can not access, eliminate the lamp environment problem, found that the firewall in the server did not open 80 ports. So I went to search the web and saw a way to add code to the script house. The code is as follows Copy Code

session state requests cannot be made to the session-state server. Make sure that the ASP. NET State Service (ASP) is started and that the client port is the same as the server port. If the server is on a remote computer, please check