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Ccie certification cost A minute to learn about the misunderstanding of SD-WAN Before we talk about the misunderstanding of SD-WAN, let's take a brief look at what SD-WAN is. SD-WAN, a wide-area software-defined network, is a service formed by applying SDN technology to a wide-area network scenario. Ccie certification cost .This service is used to connect enterprise networks, data centers, Internet applications, and cloud services across a wide geographic area.It is designed to help users reduce their wide area network (WAN) expenses and increase network connectivity flexibility. SD-WAN is more than just a buzzword, it is already bringing benefits to early adopters.Ccie certification cost .The first word about SD-WAN appeared in the public view was published in network computing in September 2014, But in fact, the concept of SD-WAN comes from the earlier emergence of Hybrid WAN, which is to solve the game problem like unstable Internet interconnection in the enterprise market and e...

Ccie certification cost Link layer discovery protocol ( LLDP)explanation(2) LLDP is an information discovery and advertisement protocol. The LLDP entity mainly maintains two MIB libraries, a local system MIB and a remote system MIB. It can also be seen from its name that one is used to maintain local related device MIB information,Ccie certification cost. and one is used to maintain remote device MIB information. LLDP initializes and maintains the local system MIB by interacting with several MIB libraries on the right side in the figure above, and advertises local related information. At the same time, when it receives information from other devices, it is updated to the remote system MIB. In this way, a device can advertise its own information and obtain information about other devices in the network, and finally obtain two MIB libraries that reflect the network topology and other configuration information. These two libraries can be used by their users to perform various funct...

Ccie certification cost Link layer discovery protocol ( LLDP)explanation With the development of network technology, there are more and more types of devices accessing the network, and the configuration is more and more complicated. Devices from different device vendors also tend to add their own unique features, which leads to many different features in a network. Ccie certification cost.Devices from different vendors, in order to facilitate the management of such networks, need to enable devices from different vendors to discover and interact with each other's systems and configuration information in the network. LLDP (Link Layer Discovery Protocol) is generated in this context, which provides a standard link layer discovery method. The information about the main device, the management address, the device identifier, and the interface identifier of the local device can be organized into different TLV (Type/Length/Value) and encapsulated in the LLDPDU (Link Layer Discovery Protoc...

Ccie exam fee A brief look at vxlan technology (4) VXLAN tunnel   "Tunnel" is a logical concept, it is not new, such as the familiar GRE. To put it bluntly, the original message is "transformed" and "packaged" so that it can be transmitted on a bearer network (such as an IP network). From the perspective of the host, it is as if there is a straight link between the start and end of the original message. Ccie exam fee.And this seemingly straight link is the "tunnel." As the name implies, the "VXLAN tunnel" is used to transmit packets that are encapsulated in VXLAN. It is a virtual channel established between two VTEPs. The payload message inside VXLAN specified in RFC7348 must be an Ethernet packet, which limits the scope of use of the VXLAN protocol. In order to allow VXLAN to support Overlay transmission of other protocol messages more widely, the RFC draft is exploring VXLAN Generic Protocol Encapsulation (GPE), which is a VXLAN ge...

Ccie exam fee A brief look at vxlan technology (3) VXLAN communication process: For two virtual terminals in the same VXLAN, the communication process can be summarized as follows: 1. The sender sends a data frame to the receiver, which contains the virtual MAC address of the sender and receiver. 2. The VTEP node connected to the sender receives the data frame. By looking up the VXLAN where the sender is located and the VTEP node to which the receiver is connected, After adding the VXLAN header, the external UDP header, and the external IP header, the packet is sent to the destination VTEP node.ccie exam fee 3. The packet is transmitted over the physical network to the destination VTEP node. 4. After receiving the packet, the destination VTEP node removes the external IP header and the external UDP header of the packet, checks the VNI of the packet, and the destination MAC address of the internal data frame.ccie exam. After confirming that the receiver is connected to the VTEP node, ...

ccie certification cost A brief look at vxlan technology (2) VXLAN is transmitted by encapsulating data frames communicated in a logical network in a physical network. Ccie certification cost .The process of encapsulation and decapsulation is performed by a VTEP node. After VXLAN adds the data frame in the logical network to the VXLAN header, it is encapsulated in the UDP packet in the physical network. • Outer MAC Header: Encapsulates the outer Ethernet header, 14 bytes, or 18 bytes if there is a VLAN TAG. The source MAC address is the MAC address of the VTEP to which the source VM belongs, and the destination MAC address is the MAC address of the next hop device on the path to the destination VTEP. The type field is 0x0800, indicating that the inner layer encapsulates an IP packet.Ccie certification cost . • Outer IP Header: Encapsulates the outer IP header, 20 bytes. The source IP address is the IP address of the VTEP to which the source VM belongs, and the destination IP...

VLAN means Virtual Local Area Network, which is the concept involved in the implementation of the switch, defined by the 802.1Q standard. Because the switch is a network device working at the link layer, the terminals connected to the same switch are in the same Layer 3 network and are also in the same broadcast domain. Ccie certification cost.When a switch accesses a large number of terminals, any one of the terminals sends a broadcast packet (for example, an ARP request), and the packet is transmitted throughout the network. For large-scale networking scenarios, the flood of broadcast packets will have a greater impact on network communications. VLAN technology provides a solution to this problem. A VLAN divides the same network into multiple logical virtual subnets. It also stipulates that when a broadcast packet is received, it broadcasts only in its VLAN to prevent broadcast packets from flooding. VLAN technology implements broadcast domain isolation at the link layer level VXLAN ...