igmp snooping

Test topologyEnvironment: DHCP server and DHCP clients belong to the same VLAN, but clients belong to different switches, and the L2 and L3 switches turn on DHCP snooping to concludeconfiguration of the L3 switch172.28.27.0 255.255.255.0172.28.27.254 172.28.28.15 ! ! 27IP DHCP snooping information option allow-untrusted //must add this command because the L3 switch also has DHCP

In our previous studies on DHCP, we found that DHCP Snooping is widely used. Although we have introduced DHCP Snooping, We will summarize it in detail here. In this example, I also gave you an illustration, hoping to give you an intuitive understanding of this part of knowledge. DHCP Server Spoofing The attacker sets up an illegal DHCP server on the vswitch and sends the IP address to the DHCP server fr

DHCPAfter the listener is enabled, the switch limits the user port to a non-trusted port. Only DHCP requests can be sent to discard all other DHCP packets from the user port.DHCP-snoopingAnother important role is to create a DHCP listener binding table. Since DHCP-snooping is so important, let's see how it is configured! Case requirements 1. The PC can obtain the IP address from the specified DHCP Server; 2. prevent other illegal DHCP servers from aff

12: 09 First, I would like to introduce myself. I am working in a ** technology company in Beijing. My company is engaged in mobile phones and has thousands of people. I am responsible for the basic network management of several outlets across the country, at the same time, I am responsible for monitoring various network devices. Now I have been in service for one and a half months. The company's leaders want to implement layer-2 security. One of them is DHCP

1. DHCP snooping parsingWhen DHCP snooping is turned on, all ports are untrusted interfaces by default.Untrusted interface: The discovery message can be received, but when an offer message is received, it is dropped directly and no DHCP message is sent.Trusted interface: Send and receive any DHCP messages. Generally, the upstream port and the port that connects to the trusted DHCP server are set to the trus

= ' SCOTT ' ORDER by last_active_time Desc; 2 3 sql_text sql_id executions-----------------------------------------------------select * from EM P where empno 3VV0T64YN0WRM 2 =: N begin:n: = 7521; End; 9b4dm4tp4k58q 1 Begin:n: = 7499; End; 2u1u06mytpsha 1 At this point the code is fully shared 2. Continue testing, turn off binding variables snooping: sql> sql> alter system set "_optim_peek_user_binds" =FALSE; System altered. Session alt

The method used is to assign IP to the user by DHCP, and then limit the way that these users can only use dynamic IP, if it is changed to static IP mode can not connect to the network; that is, the DHCP snooping function is used. Example: Version 12.1No service padService Timestamps Debug UptimeService Timestamps Log uptimeNo service password-encryptionService Compress-config!Hostname c4-2_4506!Enable Password xxxxxxx!Clock timezone GMT 8IP Subnet-z

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httpd.confChange #loadmodule vhost_alias_module modules/mod_vhost_alias.so to LoadModule vhost_alias_module modules/mod_vhost_ alias.so Change # include conf/extra/httpd-vhosts.conf to include conf/extra/httpd-vhosts.confHttpd-vhosts.conf#监听多个端口Listen 80Listen 8003Listen 8004VirtualHost*:80>#监听80端口, the address is D:\apache24\htdocs documentroot D:\apache24\htdocsVirtualHost>VirtualHost*:8003>DocumentRoot d:\apache24\htdocs/8003VirtualHost>VirtualHost*:8004>DocumentRoot d:\apache24\htdocs/8004Vi

Button tap to listen Trigger a listener event by clicking the button1Button_20 =NewJButton ("20");//Create a Button object Button_202Button_20.addactionlistener (NewActionListener () {//To Add a button listener event3 Public voidactionperformed (ActionEvent e) {4 if(Textfield_6.gettext (). Equals ("")) {5Textfield_6.settext ("20"); //Add content to the target text box 6}Else{7 intsum = Integer.parseint (Textfield_6.gettext ()) +20;8 textfield