igmp snooping

. routing ip autodhcp add/delete exclusion Add or remove an exclusion range from the DHCP allocator address range. The routing ip dnsproxy set/show global configures or displays the globally DNS proxy parameters. routing ip dnsproxy Set/show interface configures or displays the DNS proxy parameters for the specified interface. routing ip IGMP set/show global configuration or display IGMP globals. routing ip

TCP/IP protocol family 1.1 Introduction The TCP/IP protocol family consists of 5 layers: Physical layer, Data link layer, network layer, Transport layer and application layer. The first four layers correspond to the first four layers of the OSI model, providing physical standards, network interfaces, Internet connectivity, and transport capabilities. The application layer corresponds to the highest three layers in the OSI model. Each layer in the TCP/IP protocol family contains some relatively

Application examples My school is a student apartment, PC owns about 1000 units. Using DHCP assigned IP address, with 4 C class addresses, the actual number of addresses available is about 1000. Because of the frequent presence of private DHCP servers in the building, a large number of hosts cannot be assigned to legitimate IP addresses, and because a significant number of hosts specify IP addresses, conflicts with DHCP-assigned IP addresses are caused. The above two aspects, all caused the apar

This chapter describes the Internet Group Management Protocol (IGMP) that is used to support multicast for hosts and routersIt lets all systems on a physical network know which multicast group the host is currently in. Multicast routers require this information to know that multicast datagrams should be forwarded to those interfaces.Like ICMP, IGMP is also used as part of the IP layer, and

I. Working principle: A. Determine the illegal access MAC address in the network based on the DHCP Snooping or the manually formed MAC address and IP Address binding table. B. to prevent malicious ARP spoofing, the arp REQUEST packets of the interface can be limited. --- Tests show that arp requests and replies (including unreasonable arp) to untrusted ports are discarded, therefore, it is not necessary to set the speed limit on untrusted ports (no ma

Problem description How Does Cisco Hot Standby Routing Protocol (HSRP) or multi-Hot Standby Router Protocol (MSHRP) use the internal Group Management Protocol (IGMP) to interoperate with Microsoft NT 5.0 and HP AdvanceStack or ProCurve switches? Solution The two routers are connected to two different vswitch ports. HSRP and MSHRP use IP multi-point transmission datagram to ensure that one of the routers can be used as a backup when other routers fail.

, generally, this address is the same as the MAC address of the client. If an attacker modifies the CHADDR In the DHCP packet without modifying the MAC address of the client, and implements Dos attacks, Port Security does not work, DHCP sniffing technology can check the CHADDR field in the DHCP request message to determine whether the field matches the DHCP sniffing table. This function is configured by default on some vswitches and some vswitches need to be configured. For details, refer to the

Label: PIM-Sm Multicast Route pi pim-DM Multicast Route IGMP MRT PIM-DM and PIM-SM are two different modes in multicast routing ASM (any source multicast. Compared with the multicast registration mechanism of PIM-SM, the diffusion mechanism of PIM-DM is more rough. 1. The PIM-DM does not need to register the pimreg virtual interface with the kernel. But like the PIM-SM, you need to add the layer-3 interface to the MRT multicast interface. To tr

listener DHCP listeners divide vswitch ports into two types: Untrusted port: the port connecting to the terminal device. The client can only send DHCP request packets and discard all other DHCP packets from the port. Trusted port: Valid DHCP server or aggregation Port A DHCP binding table is created for the DHCP listener, which includes the IP address, MAC address, port number, VLAN, binding type, and lease period of the client on the untrusted port. DHCP binding table is the basis for further

UDP multicast can be used to broadcast data in the intarnet or Internet datagram mode (multicast over the Internet requires the router to support IGMP (Internet gateway management protocol, this Protocol appears after the IP address appears to support multicast )). compared with broadcasts that consume extremely bandwidth (broadcast can only be broadcast within the Intranet), UDP multicast has been greatly optimized, and only terminals are added to a

the number of rows in the result set directly affect the CBO's estimate of the cost value of the relevant execution steps, which in turn affects the CBO's choice of the target SQL execution plan. This means that the execution plan for the target SQL may change as the specific input values are different. For target SQL that uses bound variables, the situation is completely different, because now regardless of the specific input value of the corresponding binding variable, the SQL text of the tar

users. We recommend that you disable it.IGMP data packets: IGMP is useless for common Windows users. However, due to kernel defects in the Win9X operating system, IGMP has its own vulnerability, someone may exploit this vulnerability to send a large number of IGMP packets to a specified host, which may cause damage to the network layer of the Windows operating s

the multicast protocol, a set of protocols or mechanisms are required for the network device and the connected subnet to ensure that the network device knows the connected subnet, the number of hosts in a specific group. 2. What is the purpose of the multicast routing protocol for www.2cto.com? (1) It is the interface that discovers the upstream interface and is closest to the source. Because the multicast routing protocol only cares about the Shortest Path of the source. (2) through (S, G) pai

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 12.1 No service pad Service Timestamps Debug Uptime Service Timestamps Log uptime No service password-encryption Service Compress-config ! Hostname c4-2_4506 ! Enable Password xxxxxxx! Clock timez

Document directory IGMP multicast (IGMP Multicast) Refer: http://blog.csdn.net/ghj1976/archive/2009/03/17/3997840.aspx Recently, we are studying how to achieve Load Balancing (NLB) for csdn Forum Web servers ). Below is my documents: How NLB works Features of the NLB algorithm: In the NLB cluster, each server has its own static IP address, and all servers in the NLB Cluster also have a common IP a

1, the problem description: We have a CPE MP1803 router as a customer's CE router, the PC after the IGMP report, our router will be in the IGMP table to write the multicast group, but the customer said that the upstream of the PE device does not receive the PIM of our equipment Join message and ultimately cannot draw the multicast traffic down. After the investigation, found that customers in the same loc

Abstract: multicast communication is a hot network technology. This article describes the basic concepts of IP multicast technology, multicast addressing, Internet Group Management Protocol (IGMP), multicast routing algorithms, and existing multicast routing protocols, and the new multicast routing protocol being studied. It also introduces the main problems in multicast: security issues and QoS issues, and briefly introduces the present situation and

address of 192.168.0.1 can access any hostSwitch (config) Permit any 192.168.0.1 0.0.0.0# define all hosts can access hosts with IP address 192.168.0.1Switch (config-if) interface fa0/20#进入配置具体端口的模式Switch (config-if) Mac Access-group MAC10 in# Apply an access list named MAC10 on the port (that is, the access policy we defined earlier)Switch (config-if) Ip Access-group IP10 in# Apply an access list named IP10 on the port (that is, the access policy we defined earlier)Switch (config) no Mac Acces

Some of the content in DHCP configuration is started by dai. So here we will summarize the content in this regard. Next, let's take a detailed look at the specific operations of DHCP dai startup. The DHCP dai STARTUP configuration command is as follows: Ip subnet-zero Ip dhcp excluded-address 192.168.1.1 ! Ip dhcp pool test Network 192.168.1.0 255.255.255.0 Default-router 192.168.1.1 Dns-server 192.168.1.1 Lease infinite ! Ip dhcp snoo