ccie security v5 written exam cost

ccie security v5 written exam cost

R1(config)#no cdp run disables CDP protocol in global configuration mode ( affects all interfaces ) r1(config-if)#no cdp enable disables CDP protocol on interface ( only affects the specified interface ) clear cdp table clears CDP neighbors table When configuring IGRP , you need to pay attention to the autonomous system number . Vlan database enters the VLAN configuration mode of the VLAN Relay Cell ( Cell Relay ) using small fixed size packets ( called cells ) technique. Their solid show ip eigrp topology view EIGRP topology database ( table ) Each non-root bridge elects a root port 1) Bandwidth Cost Lowest 2) Recevied BridgeID Lowest coimnection ID ( connection ID) ----- each into the router's Telnet identifying the session analysis. Show When to disconnect Enable password Set the plaintext enable password Interface serial 0 =========================================================== =============== AURP tunnel (AURP tunnel ) connection in an AURP WAN , which is physically divided into two data direct VCC ( data direct VCC) ATM two LEG to establish a two-way point between the MCR and PCR Fallback (in the fall ) ATM network, this mechanism is used to get a path, if it can not use the regular side Frame Relay switching ( Frame Relay switching ) service provider router frame relay packets provided algorithm ( algorithm ) to a set of rules or procedures to solve a problem. Algorithms in the network are generally used IBM agency link. See FRAD . IGRP uses a 24-bit metric . DUAL Diffusing Update Algorithm (Diffusing Update Algorithm) used in the Enhanced IGRP ,ccie security v5 written exam cost, this =========================================================== =============== The pick-up point is specified in the destination field of the packet. See SSAP and SAP . A Cisco hierarchical network. The core layer quickly passes packets to the distribution layer device. No packet filtering is performed at this level. Debug ip eigrp notifications debug event notification A regional border router between an OSPF autonomous system and a non- OSPF network, operating OSPF and an additional routing protocol ( such as RIP) . The ASBR must be in a non-stub OSPF area. See ABR , non-stub area, and OSPF . Router, which is required for other special tasks in OSPF operations. A multi-access OSPF network with at least two routers selects a router through the OSPF Hello protocol, which makes the multi-access network necessary neighbors. Frame-relay map ip 10.1.1.2 110 broadcast for manual static mapping This interface of the 7000 Series router minimizes the performance bottleneck of the UNI . Participate in AAL3/4 private AAL5 . Basic FRAME-RELAY configuration B(config)#inte s 0 B(config)#access-list 1 permit any The data can exceed the bandwidth normally reserved for the connection, but cannot exceed the port rate. An example of this is a 128Kb/s Frame Relay CIR on T-1 - depending on the vendor, it is possible to send at a rate of more than 128Kb/s for a short time . fault tolerance ( fault-tolerant ) network device or the communication link may fail without interrupting communications degree. Fault tolerance CO central office (central office) , all circuits in a certain area are connected here, is the subscriber line 1. CISCO 2. ANSI 3. Q993A A data link product from EtherTalk Apple Computer Inc. that allows AppleTalk networks to be powered by Ethernet Node group. A direct broadcast is indicated by its broadcast address, which is a destination subnet address where all bits are one . Configure the ISDN switch type and select it according to the regionality. R14#debug isdn events R14#show isdn active byte-oriented protocol ( byte oriented protocol ) to mark the frame boundaries, the use of a user character =========================================================== =============== Address mapping . Free Fragment Forwarding (cisco private technology ): between pass-through forwarding and storage forwarding performance . Show version Observe the IOS version device working time related interface list show running-config View the currently active configuration This configuration file is stored in RAM show interface ethernet 0/1 to view the status of the Ethernet interface working status, etc ... Configuring VTP Connectionless ( no connection ) does not require the creation of data transfers from virtual circuits. It has no overhead, try its best PPP authentication method : the alignmentError ( alignment error ) Ethernet The error occurring in the network, the received frame in which the additional Used to connect to remote sites . =========================================================== =============== Interface serial 0 Used to " fused " the capabilities of various routers and switch sets . Spanning tree port CIDR stepless routing domain (Classless Interdomain Routing) stepless routing protocol A remote AppleTalk location access protocol for resources and data. routing Classless ( stepless routing ) transmits routing update routing subnet mask. Stepless road =========================================================== ===================== Copy running-config startup-config saves the current configuration concept : Duplex Full ( full duplex ) ability to simultaneously transfer information between the transmitting and receiving stations, see Ethernet cable type for switch or switch to hub. Bit, Frame, Packet, and Segment are all called : PDU (Protocol Data Unit) excess rate ( over rate ) in the ATM network, a connection over the insurance rate traffic. super Frame Relay ( FR ) ----- the X.25 protocol ( a guaranteed unrelated packet relay data transmission techniques ) in a more effective alternative. Frame Relay is an industry-standard, shared, and best-effort switched data link layer package that provides multiple virtual circuits and protocols between connected mechanisms. =========================================================== =============== Create a VLAN Configure the ISDN switch type and select it according to the regionality. 1.Server mode < main > 2.Client mode < time > 3.TransParent mode < transparent > Basic Management Setup ( basic management established ) Cisco routers to establish mode. only Cable Crossover ( crossover cable ) is connected to the switch switches, host-to-host, hub to hub Configure a password for the console port : ITU-T standard. Currently BISDN uses ATM technology and SONET- based transmission circuits to provide 155Mb/s and The distance limit of each segment of 1OBaseT is about 100 meters. See Ethernet and IEEE 802.3 . Connectionless link. It is mainly used to send SMDS packets on the ATM network . See AAL bridge group ( bridging group ) in a bridge configuration of the router, bridge group number determined by a unique A data link product from EtherTalk Apple Computer Inc. that allows AppleTalk networks to be powered by Ethernet ATM user-user connection (ATM user - user connection ) A connection established by the ATM layer to provide Medium is classified by channel with a bandwidth greater than 4 kHz ( typical voice level ) . It uses simulation in LAN technology WAN : Cable Crossover ( crossover cable ) is connected to the switch switches, host-to-host, hub to hub The station's HDLC communication mode, where the transmission can start from the primary station or a secondary station. call priority ( call priority ) circuit switched system, the originating port to the priority of each definition, it AARPprobepackets (AARP probe packets ) AARP packets sent, for determining a non-extended Network or subnet, which part represents the host. Sometimes referred to as a mask. Playing subnet mask A technique that automatically starts and ends a circuit switched session. By imitation remains active, the router tricks the end station to treat the session as active. DDR is allowed through a modem or an external ISDN terminal adapter Centrex ( Central Switch ) A local switched carrier service that provides local handover similar to live PBX =========================================================== =============== DCC data Country Code (Data Country Code) developed by the ATM Forum for the use of private networks Externally connected to each interface of the device. This technology can be used by bridges and switches to transmit traffic over the network. Propagation through hubs and repeaters, but not through LAN switches, routers, or bridges. See collision . COmposite metric ( complex metrics ) with IGRP and EIGRP use with such routing protocol, frame filtering ( frame filtering ) frame in the second filter 2 layer switch to provide more bandwidth. Switch reading Router, which is required for other special tasks in OSPF operations. A multi-access OSPF network with at least two routers selects a router through the OSPF Hello protocol, which makes the multi-access network necessary neighbors. 1. Static NAT 2. Dynamic NAT 3. PAT A particular connection increases the amount of available bandwidth. binary ( binary ) by 1 and 0 two methods of counting characters. Binary count is made for all information 1. in direction 2. out to party Backbone ( backbone ) basic part of the network, which provides sent to other networks and other networks originating from A (config-if) #ip rip authentication key-chain A selected A key chain convergence ( convergence ) Internet in all routers update their routing tables and create a consistent In ABR service allows a congestion feedback mode. EFCI can be set by any network element in immediate or some kind of congestion state. The destination end system can perform a protocol that adjusts and lowers the cell rate of the connection based on the EFCI value. See ABBR . broadcast domain ( Radio City ) receiving apparatus of any broadcast frame sent from a device in the device group =========================================================== =============== PPP: =========================================================== =============== Copy tftp: running-config copy startup-config tftp: =========================================================== =============== Network connection. =========================================================== =============== Each non-root bridge elects a root port 1) Bandwidth Cost Lowest 2) Recevied BridgeID Lowest Servers, workstations, ATM- to- LAN switches, and ATM routers. When they meet, the frames of each node collide and are damaged. See collision domain . Where to perform circuit switching. The three-tier architecture of the network : Cost ( cost ), also known as path cost, an arbitrary value, based on the number of hops, bandwidth, or other juices, Immediate execution , immediate effect Expansion ( competition ) directs compressed data through an algorithm that restores the information to its original size. Directed broadcast (a direct broadcast ) a data frame or packet is transmitted to a remote network segment specific AS AS (autonomous system) a group of networks under the management of another, they share the same =========================================================== =============== ------------------------------------------------ End directly returns to privileged mode Whether a given node ID in an AppleTalk network is used by another node. If the node ID is used at the end, the sending node can use the ID of that node . If the node ID is already used, the sending node will select a different ID and send more AARP probe packets. See AARP congestion avoidance ( congestion avoidance ) to minimize latency, the ATM network for controlling the system into coimnection ID ( connection ID) ----- each into the router's Telnet identifying the session analysis. Show BGP neighbors (BGP neighbor ) starts a communication process to exchange routing information dynamically two ARP ARP (Address Resolution Protocol) in RFC 826 is defined in the protocol Non-designated port is placed in blocking state " The main explanation is F , G , H vocabulary beginning. AIP ATM Interface Processor (ATM Interface Processor) ----- supports AAL3 / 4 and AAL5. Cisco CONSOLE PORT ( management console interface ): distance limit , exclusive way . Terminal history size <0-256> set command buffer size 0: means no cache Configure virtual loopback interface ( loopback interface defaults to UP state ) inerface loopback? Create a loopback interface To authenticate, the user and password uniquely identify them. Connect the SDLC device to Frame Relay without the need for an existing LAN . It is also possible to upgrade to a full-featured multi-protocol router. The conversion from SDLC to Ethernet and Token Ring can be activated , but the attached LAN is not supported . See FRAD . Propagation through hubs and repeaters, but not through LAN switches, routers, or bridges. See collision . COmposite metric ( complex metrics ) with IGRP and EIGRP use with such routing protocol, DVMRP distance between the amount of multicast routing protocol (Distance Vector Multicast Routing Protocol) is mainly based on Routing Information Protocol (the RTP) , the Internet gateway protocol a common, strong bridge identifier ( bridge identifiers ) for the first 2 discovery layer switched internetwork and network selection root Create a standard 5 sub-section ATM cells. The ATM layer receives 48- byte segments from the AAL and appends a 5- byte header to each segment . These cells are then sent to the physical layer for transmission over the physical medium. See AAL . Connectionless ( no connection ) does not require the creation of data transfers from virtual circuits. It has no overhead, try its best " The main explanation is B , C words that begin with. (ChinaITLab) The process of OSPF creating neighbors : Layer , Presentation layer , Session layer , and Transport layer . data terminal equipment ( Data Terminal Equipment ) , see the DTE . Choose an agreement. AFI privilege and format identifier (Authority and Format Identifier) ​​A part of the NSAP ATM address IOS Cisco Cisco Internetwork Operating System Software (Cisco Internetwork Operating System software) ----- as CiscoFusion provide the functionality shared by all products in the off-line configuration, scalability and security of Cisco core routers and switches series. See CiscoFusion . end-to-end VLANs ( end the VLAN) ----- across the switch fabric (switch-fabric) from end to end mask address ( address mask ) a bit pattern descriptor, which identifies which portion of a network address of the representative AppleShare and Mac OS file sharing allows users to share files and applications on the server. Create a VLAN =========================================================== =============== FRAME-RELAY topology (pvc) 1. Port-based implementation , static VLAN 2. Based on MAC address implementation , dynamic VLAN TRUNK ( trunk ): uses a special encapsulation mechanism to transfer data from multiple VLANs . Duplex Auto ( automatic duplex ) of a layer and 2 a device layer disposed on, it automatically switches provided BGP (Amplitude magnitude ) the maximum analog or digital waveform. expedited delivery ( accelerated delivery ) may be the same or other layers of protocol of a different network device in CHAP: Challenge three-way handshake , the password is transmitted by HASH algorithm , which is stronger than PAP. =========================================================== =============== EIGRP uses a wildcard mask configuration example : Enable enter privileged mode ACL two actions : Propagation through hubs and repeaters, but not through LAN switches, routers, or bridges. See collision . COmposite metric ( complex metrics ) with IGRP and EIGRP use with such routing protocol, The E-1 transmission line can be leased from a public carrier company for use as a dedicated line. =========================================================== =============== Information can be used to determine if the network has recently caused a change in the problem. QoS class. CBR is used to rely on accurate clocks to ensure reliable transmission connections. Compare ABR and VBR . Different frequency and phase relationships. Asynchronous transfers typically encapsulate a single character in control bits ( called start and stop bits ) The input is copied over the length of the medium and received by all other stations. Compare ring and star . Configure a password for the console port : Acknowledgment ( acknowledgment ) is transmitted from one network device to another network device authentication, showed a HDLC specifies a method of encapsulating data on a synchronous serial link and is the default for Cisco routers =========================================================== =============== The location of the standard access control list application : the location of the access control list application that is applied to the interface that is closest to the target : the application is in the interface closest to the source, show ip interface serial 0, to view the configuration of the interface's acl . =========================================================== =============== FRAME-RELAY topology (pvc) =========================================================== =============== Interface Serial1 no ip address Dynamic VLAN ( Dynamic DLAN) A manager that creates entries in a special server. Router igrp as number is the autonomous system number ( autonomous domain ) network main class network number ABC number debug ip igrp events debug igrp related events AS path prepending (AS path pre-planned ) use route maps by adding fake ASN extended from CPCS CPCS layer (Common Part Convergence Sublayer) two business =========================================================== =============== Segment, even the port field in the transport layer header filters the IP address table of the network between. It is also the time it takes for a packet to travel from its source through a path to its destination. See latency . Demarc ( demarcation ) The demarcation point between the Customer Premises Equipment (CPE) and the telephone company carrier equipment. BGP peers (BGP peers ) See BGP neighbors . Clock rate ? Configure the clock frequency of the DCE interface ( system specified frequency ) A random value selected by the BGP router when sending an OPEN message. The minimum information transmission rate agreed by the Frame Relay network, measured in b/s . Encryption ( encryption ) converting the information into a form clutter to effectively disguise, so as to prevent an authorized end ACL two actions : the alignmentError ( alignment error ) Ethernet The error occurring in the network, the received frame in which the additional Action : Permit Let " . In this scheme, each T-1 uses one bit of each sixth frame on the channel to transmit monitoring signaling information. edge. When any member of the peer group wants to find a resource, it sends a probe to the border peer. The border peer then forwards the request on behalf of the requesting router, thus eliminating duplicate traffic. VTP is a messaging system . Ensures that all of the switches in the same management domain below network VLAN 1. CISCO 2. ANSI 3. Q993A 4. Notification method : Broadcast (RIPv1, IGRP) rule mechanism : Handshake ( handshake ) to ensure synchronous transmission of a series of operations exchanged between two or more devices on a network. dynamic entries ( dynamic entries ) for the first 2 layer and 3 to create a hardware device address dynamically layer FDM frequency division multiplexing (Frequency-Division Multiplexing) allows several channels to the channel Servers, workstations, ATM- to- LAN switches, and ATM routers. =========================================================== =============== Port 179 . Also known as "BGP peers " . ------------------------------------------------ There is a command line interface function. DCC data Country Code (Data Country Code) developed by the ATM Forum for the use of private networks Designated bridge (the designated bridge ) has the most in the process of forwarding frames from a network segment to a routing bridge. Router, which is required for other special tasks in OSPF operations. A multi-access OSPF network with at least two routers selects a router through the OSPF Hello protocol, which makes the multi-access network necessary neighbors. ATG Address Translation Gateway (Address Translation Gateway) ----- Cisco DECnet routing software is a mechanism that allows the router route multiple, independent DECnet networks and to establish a user-specified address into a network between the selected nodes. BPDU: Bridge Protocol Data Unit Bridge Protocol Data Unit Control direct VCC . Broadcast ( Broadcast ) ----- a data frame or packet is transmitted to the local network segment ( defined by the broadcast domain ) for each node on. Broadcast broadcast address indicated by its destination network and host address bits are all 1 . Also known as " local broadcast " . Compare directedbroadcast . Equipment and Tnter have jointly improved. Ethernet is similar to the TEEE802.3 family of standards and uses CSMA/CD to operate at lOMb/s rates on various types of cables . Also known as DIX (Digital/Intel/Xerox) Ethernet. See Encapsulation ( encapsulation ) layered association, the technology used, one layer to the upper layer protocol data unit Line conosle 0 to consolo 0 =========================================================== ================ Flapping ( flip ) describe a term serial interface to be opened and closed. FEIP Fast Ethernet Interface Processor (Fast Ethernet Interface Processor) Cisco7000 Series Routing MCR and PCR And track . 1 th D channels ( each 64Kb / s) a part in which a single channel or channel group are connected to different destinations, supports the DDR , Frame Relay, and the X.25 . Compare channelized E-1 . =========================================================== =============== The quantity manages a QoS parameter specified when the connection is established . In CBR transmission, the degree of allowable fluctuation of data sampling by PCR is determined by the CDVT . See CBR and PCR . Interface s 1 no ip add Router eigrp 100 broadcast domain ( Radio City ) receiving apparatus of any broadcast frame sent from a device in the device group 20s 15s 15s IOS Cisco Cisco Internetwork Operating System Software (Cisco Internetwork Operating System software) ----- as CiscoFusion provide the functionality shared by all products in the off-line configuration, scalability and security of Cisco core routers and switches series. See CiscoFusion . Port 179 . Also known as "BGP peers " . Set a user password or authentication protocol Other routers maintain a record of existing available routes AEP AppleTalk Response Protocol (AppleTalk Echo If the router has a loopback interface , select the highest IP from the loopback interface as the RouterID. IGRP is a CISCO private routing protocol that can only be implemented and deployed on CISCO routers . ATCP AppleTalk control program (the AppleTalk Control Program) : establishing and configuring AppleTalk over Control direct VCC . A particular connection increases the amount of available bandwidth. =========================================================== =============== access. Each encryption scheme uses some precisely defined algorithm that is reversed by an opposite algorithm during the decryption process at the receiving end. B8ZS binary 8 replacement - a line coding, explained at the far end of the connection, when transmitting eight zeros continuously on the link of the T-1 and E-1 circuits, it uses a special Code replacement. This technique guarantees that the density of 1 is not constrained by the data stream. Also known as bipolar 8 zero replacement. Compare AMI . See ones density . 2. Topology Table => Network Map Cost ( cost ), also known as path cost, an arbitrary value, based on the number of hops, bandwidth, or other juices, Different frequency and phase relationships. Asynchronous transfers typically encapsulate a single character in control bits ( called start and stop bits ) The process of segmenting a packet into small pieces. When they meet, the frames of each node collide and are damaged. See collision domain . ACL for packet processing : bridge. The bridge ID is a combination of bridge priority and base MAC address. Mesh Full ( full mesh ) network topology, wherein each node to other network nodes or virtual physical choke packet ( packet that was blocked ) when congestion exists, it is sent to the sender of a packet, it should inform Routers running BGP ; they use a TCP port on layer 4 of the OSI Reference Model . Especially using TCP collapsed backbone ( folded backbone ) all network segments via a network interconnection device connected to each other The network node becomes the activity monitor and is responsible for managing tasks such as preventing loops and ensuring that tokens are not lost. And headers and trailers for synchronization and error control, which surround the data contained in the unit. Surgery. The IBM network is called pacing, meaning that when the receive buffer is full, a message is transmitted to the sending unit to suspend transmission until all data in the receive buffer is processed and the buffer is ready to receive again. Storage forwarding : slow , ensuring the correctness of the frames being forwarded . Broadcasting is not supported by FRAME-RELAY , which will cause the route to be unadvertised . Solution : Copy multiple frames for announcement. The address is all ones . For hardware addressing, the hardware address will be all 1s in hexadecimal ( ie all F) . (Amplitude magnitude ) the maximum analog or digital waveform. Source port : None dedicatedline ( green ) do not share any bandwidth point to point connection. Data link layer : Network layer : A random value selected by the BGP router when sending an OPEN message. Rate enhancement and VCT conversion. See ATM . Support for multiple network layer protocols through NCP can achieve " authentication ", " compression ", " error detection ", " multi-link " through LCP . cut-through frame switching ( straight-frame exchange ) A frame of data flowing through the switch switching technology routing Classless ( stepless routing ) transmits routing update routing subnet mask. Stepless road DCE data communication device ( by JIA defined ) or a data circuit-terminating equipment ( according to ITU-T defined ) constituted by show vtp status view VTP status Static NAT configuration Line conosle 0 to consolo 0 frame identification (frame tagging) ( frame identifier, frame flag ) the VLAN can span multiple connections CSMA / CD carrier with Collision Detection Sense Multiple Access (Carrier Sense Multiple Access / Collision Detect ) Ethernet IEEE802.3 a technology committee defined. Every device is sending Configuration with multipoint subinterface Endpoints ( endpoint ) see BGP neighbors . E.164 1) evolved from the standard telephone numbering system, which is numbered by ITU-T , especially at GNS the nearest server (Get Nearest Server): in the IPX network, to determine a customer a request of a given type of packet location nearest transmitted activation server. An IPX network client issues a GNS request to obtain a response from a connected server or a response from a router that discloses the location of the server on the internet. GNS is part of IPX and SAP . See IPX and SAP . call priority ( call priority ) circuit switched system, the originating port to the priority of each definition, it Code IP over ATN equipment. Baseband ( baseband ) a characteristic of network technology, the use of only one carrier frequency. Ethernet is one outside interface address is unknown , how do PAT configuration commands Demodulation ( demodulating ) a modulated channel port returns to its original form of a series of steps. Modulation when receiving The area of ​​the possibility of being discarded. Cells with CLP=0 are considered to be guaranteed traffic and cannot be discarded. A cell with CLP = 1 is considered to be an effortful traffic, which can be discarded when congested, submitting more resources to handle the guaranteed traffic. Configure the ISDN switch type and select it according to the regionality. A(config)#key chain A configuration key chain A Cell ( Cell ) the ATM network, the basic unit of data switching and multiplexing. The cell has a 53 byte Static NAT configuration 1.Down 2.Init 3.Two-Way 4.ExStart =========================================================== =============== Reduce the send rate. To understanding the Authorization ( authorization ) based on the AAA model of identity to allow access to a resource behavior verification. An ATM network configured with a ring of LAN . Multiple ELANs can exist simultaneously on one ATM network and form a LAN Emulation Client (LEC) , a LAN emulation server, a Broadcast and Unknown Server (BUS), and a LAN Emulation Configuration Server (LECS) . ELAN is defined by the LANE specification. See LANE , LEG , LEGS, and LES . Setup manually enter the setup configuration mode Media type : twisted pair , coaxial cable , fiber the adjacency ( abutting ) the relationship between the neighboring routers and end nodes use a common media segment established to Copy running-config startup-config saves the current configuration concept : IGRP configuration Packet exchange. The process of activating an interface that has been frozen by the pruning process. It is initiated by an IGMP member report sent to the router . Username 123 password cisco configuration user name password database , used to verify each other Set when to dial R14 (config) #access-list 1 permit any =========================================================== ================ A(config)#key chain A configuration key chain A Experiment : Endpoints ( endpoint ) see BGP neighbors . The minimum information transmission rate agreed by the Frame Relay network, measured in b/s . Password cisco sets a password to "cisco" =========================================================== =============== HDLC: AAL1 ATM Adaptation Layer 1 One of the four AALs recommended by ITU-T for connection-oriented, constant GMII dry megabits MII (Gigabit MII): providing a data transmission . 8 -bit Media Independent Interface. =========================================================== =============== Protocol : ICMP (Internet Control Message protocol) An international standard for transmitting cells in a variety of business systems, such as voice, video or data. The reduction in transmission delay is due to the fact that fixed length cells are allowed to be processed in hardware. ATM is designed to enable high-speed transmission media ( such as SONET , =========================================================== =============== The metric is 32 bits long, the K values ​​are not equal , and the neighbor relationship cannot be created. The AS autonomous system is different , and the neighbor relationship cannot be created. At a rate higher than T1 , hello packet is sent every 5 seconds , at a rate lower than T1 . On , will send hello every 60s IGRP: based on bandwidth, latency, reliability, load, MTU (maximum transmission unit) The input is copied over the length of the medium and received by all other stations. Compare ring and star . 1. The content of the announcement : a copy of the routing table (copy) 2. The time of the announcement : periodicity 3. The object of the announcement : the directly connected neighbor router And headers and trailers for synchronization and error control, which surround the data contained in the unit. Freedom debris forwarding mechanism , can only CISCO achieve on the device . Password cisco login CCNA is Cisco's most basic entry certification. Among them, the test focuses on network concepts and theories. For beginners, many professional English terms are difficult to understand, which makes the students' learning progress difficult. The original textbook of CISCO series certification, the frequency of professional vocabulary appears, as long as the candidates are familiar with this article, I believe that learning will definitely do more with less.