Shulou(Shulou.com)06/02 Report--

"Windows system Management"

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What is BIOS? How to enter BIOS?

BIOS basic input and output system, generally press DEL or F2 to enter the BIOS setup program. What is a virtual machine?

A software program running on a computer that simulates computer hardware functions to provide an independent design for other software programs.

Computer environment. Virtual machine operation mode?

1) sojourn structure

Installed as an application on the operating system, multiple operating systems can be installed on this application

2) Native architecture

The virtual machine software is installed directly on the computer hardware

The virtual machine itself is an operating system IP address function, composition, classification?

1) function: the network address used to identify a node

2) composition: network bit + host bit, 32 bits, represented by 4 decimal numbers, used in between. Separate

3) Classification:

 A 1-127net + Master

 B128191 Network + Network + Master + Master

 C 192-223 Network + Master

 D224239 Multicast (Multicast)

 E 240254 Scientific Research

4) default subnet mask

 Class A 255.0.0.0

 Class B 255.255.0.0

 Class C 255.255.255.0 standby configuration dedicated IP address?

169.254.0.1-169.254.255.254 with a subnet mask of 255.255.0.0 private address range:

Category A 10.0.0.1 ~ 10.255.255.254

Category B 172.16.0.1 ~ 172.31.255.254

Class C 192.168.0.1 ~ 192.168.255.254 Common built-in user accounts

1) Administrator (administrator user) default administrator user. This account cannot be deleted. Rename it for security reasons.

2) Guest (Guest user) is disabled by default and is available for temporary use by users who do not have an account. It has only limited permissions. What is the meaning of ALP rules?

Add local users to local groups, and finally only assign permissions to local groups (meaning of ALP rules) commonly used file systems

How to access shared folders by FAT, NTFS and EXT

1) browse through "Network" ("Network Discovery" must be enabled)

2) through the UNC path:\ server address\ share name

3) Mapping network drive: net use H:\ server IP\ share name what is a printing device and what is a printer?

1) Printing device (physical):

Also known as a physical printer, a hardware device used for printing

2) Printer (logical):

Also known as logical printers, the advantages of software dynamic disks added to the use of printing devices

Compared with the basic disk, it has stronger scalability, high reliability and high read and write performance. Characteristics of five kinds of dynamic disks

Volume type disk number storage capacity performance failover

Simple Volume 1 all

32 spanned volumes are all unchanged

Belt volume 2-32 all read and write promote many none

Mirror volume 2 half read promotion, write drop, support fault tolerance, the general operating system on this volume has

RAID-5

Volume 3: 32 disks-1 read promotion, write drop, fault tolerance, fast reading speed, general data on this volume

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"Windows Services and Security"

# what is a domain?

The computers in the network are logically organized together for centralized management. This centralized management environment is called a domain what is a domain controller (DC).

In the domain, there is at least one domain controller, the user account and security database of the entire domain are kept in the domain controller, and the activity is installed

A computer in the directory is called a domain controller, and domain administrators can control the behavior of each domain user. Active Directory (AD)

Active Directory: a directory database that stores information about objects throughout the Windows network. It is also a service that provides access to

The data in the active directory performs various operations by default GPO?

Default Domain Policy (Default Domain Policy)

Default Domain Controller Policy (Default Domain Controllers Policy) commands to turn on local security policy

Secpol.msc forced refresh policy

Gpupdate / force Group Policy Application order

Order in which Group Policy is applied: LSDOU

Local Group Policy site domain OU

If OU conflicts with sub-OU, what is DNS and what is the effect of sub-OU?

DNS (Domain Name System) domain name system

Function: domain name is resolved to IP address, IP address is resolved to domain name. DNS common resource records

A (host): forward resource record

PTR (pointer): reverse resource record

MX (Mail Exchange): Mail server

CNAME (alias): what are subdomains and delegates of the other FQDN names of a server, and what is the difference between the two?

Subdomains: you can create subdomains in the zone to expand the domain name space

Delegate: delegate subdomains to other servers for maintenance

The difference between subdomains and delegates:

The resources of the child domain are in the parent zone file, and the authoritative server of the child domain is the authoritative server of the parent zone.

Delegate independent zone files to assign new authoritative server FTP download and upload data commands to the new domain

Get, mget (download multiple)

Put, mput (upload multiple) what is FTP and port number?

FTP File transfer Protocol

Port number 21 of TCP (control connection)

With 20 (data connection)

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"basic network construction"

# what is the line order of T568b?

What is the structure and function of white orange, orange, white-green, blue, white-blue, green, white-brown, brown IP address?

The structure is divided into network bits and host bits, which are distinguished by the subnet mask; length 32bit

The function is: in a certain range, the only representation of a network device; what is the structure and function of the MAC address?

The structure is the custom number of the first half, which is divided into the manufacturer code and the second part, and the length is 48bit

The purpose is: on a global scale, the only representation of a network hardware device; what is the role of ARP?

Based on the IP address, the corresponding MAC address is obtained in order to realize the fast encapsulation of the data frame. Based on the difference of line order, what are the common types of network cables?

Straight line: the line order at both ends is the same.

Cross line: 568A line sequence on one side and 568B line sequence on the other

Reverse line: the order of the lines on both sides is completely opposite; under what circumstances is the crossing line used?

Use crossover lines when connecting devices of the same type; what is swapping?

Communication within the same network segment is called "switching"; how does the switch work?

1) form the MAC address table

When the switch receives a data frame on a port, it associates the source MAC address in the data frame with the incoming port.

Into an MAC address table entry

2) find the MAC address table

The switch compares the destination MAC address in the data frame with the MAC address table entry. If the corresponding entry can be found, the base

Forward out the port; if no corresponding entry is found, broadcast (that is, sent from a port other than the incoming port), what is a route?

Communication between different network segments is called "routing"; what is the difference between TCP and UDP?

TCP links are stable, but link establishment is time-consuming and delayed.

UDP transmits data quickly, but it is easy to lose data and is unstable.

What are the categories of 11.IP addresses?

A-0277

B-12800191

C-192-23

D-2240239

E-240,255

What is the 12.IP private address space?

A: 10.0.0.0-10.255.25.255

B: 172.16.0.0-172.31.255.255

C: 192.168.0.0-192.168.255.255

D: 239.0.0.0-239.255.255.255

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"Network Construction of small and medium-sized Enterprises"

# what is VLAN?

VLAN, which refers to virtual local area network, is a two-layer technology. Broadcast domain isolation can be achieved on the switch. Thus, the impact of data broadcast storm on the switching network can be reduced, the difficulty of network management can be reduced, and the flexible expansion of network scale can be realized. What is the difference between a Trunk link and an Access link?

Trunk links can support data forwarding of multiple VLAN at the same time.

Data carries VLAN tags (except native vlan)

Access links can only transmit data of one VLAN at a time.

There is no label for the data sent and received; what is the hybrid port in Huawei switch?

Hybrid port, called hybrid / promiscuous port. Is the default mode for Huawei switch ports.

It can realize not only the function of access link, but also the function of trunk link.

The label carried by the data forwarded on the port can be flexibly controlled. What STP protocol?

STP, which refers to spanning Tree Protocol.

When there are redundant links in layer 2 network, it is used to prevent the occurrence of layer 2 data forwarding loop. Describe how STP works

By default, the switch turns on the STP function. After powering on, send and compare BPDU to each other with the connected switch

This ensures that there is only one shortest, loop-free, layer 2 data forwarding path to any device in the network. The specific process is as follows:

# first determine the role of the switch: root switch and non-root switch

# secondly, determine the role of the port: root port, designated port and non-designated port

# finally determine the status of the port: what are the election principles for the root switches of down, listening, learning, forwarding and blockingSTP?

Determine by comparing the BID (bridge ID) of each switch.

First of all, compare the priorities. The smaller the value, the better. The default value is 32768.

If the priority is the same, compare the MAC addresses, the smaller the value, the better; what are the encapsulation protocols for Trunk links?

802.1Q and ISL.

The former is a public standard, which adds 4 bytes to the original data.

The latter is a Cisco private protocol that adds 30 bytes to the original data; how does the router work?

After receiving the packet, make a "routing table" entry based on the destination IP address in the IP header

If the match is successful, it is forwarded out on the corresponding interface; if the match fails, the packet is discarded; what is a gateway?

That is, the exit when one network segment goes to another. What is SVI?

SVI, which refers to a switched virtual port, represents a layer 3 IP interface corresponding to a VLAN, which is generally used in the VLAN

The gateway IP for all member hosts of the What are the types of STP?

802.1D-STP, spanning Tree Protocol

802.1W-RSTP, Rapid spanning Tree Protocol

802.1S-MSTP, multiple spanning Tree Protocol; what is the convergence time of STP?

What are the roles and status of switch ports in 30s~50sRSTP?

-Port role

Root port, designated port, alternate port (replaced by root port),

Backup port (designated port is backed up)

-Port statu

Learning: learning status; forwarding: forwarding status; discarding: what is the purpose of discarding status GVRP?

GVRP, the generic VLAN registration protocol, is a public protocol.

It is mainly used to automatically synchronize VLAN information between switches to ensure the consistency of the VLAN information database on the switch. What is the purpose of DHCP?

By setting up a DHCP server, IP addresses and other related parameters are automatically assigned to the end host.

Thus, the batch allocation and management of IP addresses are realized, and the management efficiency is improved. RIP is divided into several versions. How does it work?

RIP is divided into RIPv1 and RIPv2

Principle:

After the router runs the RIP protocol, it periodically sends RIP update messages on the port on which the process is started, ensuring that the router

The RIP database saved between is completely synchronized.

After receiving the RIP message, the router puts it into the RIP database and selects the best route entry to put into the routing table.

When the network changes, RIP will quickly send update messages to notify other RIP routers.

Used to ensure the stability and connectivity of the entire network.

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"large-scale enterprise network construction"

# what is the purpose of VRRP?

VRRP, which refers to the virtual gateway redundancy protocol.

The function is to form virtual gateway IP addresses between different gateway devices, thus realizing backup redundancy between gateway devices.

Enhance the stability of the gateway. What is the purpose of NAT?

NAT, which refers to network address translation

The function is to realize the translation between the private IP address of the internal network and the public IP address of the external network, so as to realize the interworking between the internal network and the external network.

At the same time, it can hide the structure of the internal network and enhance the security of the network. What are the types of NAT?

Static NAT,

Dynamic NAT, in which the package also contains the commonly used PNAT (port NAT) ACL functions and types and what are the differences?

ACL, which refers to access control lists

The function is to match the interested traffic and filter the traffic with tools.

Basic ACL and extended ACL.

Difference:

Basic ACL can only match the source IP address in the IP header

The extended ACL can match both the source IP address and the destination IP address in the IP header, as well as the contents of the transport layer protocol, and control

Traffic is more accurate. What is the purpose of OSPF?

OSPF, which refers to the open shortest path first protocol.

The function is to quickly form a shortest, loop-free, three-layer forwarding path within the corporate network. What is the working process of OSPF?

# first build the OSPF adjacency table

# second, synchronize OSPF database

# finally, calculate the OSPF routing table; what is the status of establishing neighbors in OSPF?

# down, port does not have OSPF protocol enabled

# init, initialization status

# two-way, two-way communication status

# exstart, exchange initialization status

# exchange, exchange status

# loading, loading status

# full, full adjacency status; which layer of OSI does OSPF belong to? How do you express it? What are the message types?

OSPF belongs to OSI layer 3, and the protocol number is 89

The message types are:

 Hello: hello package for neighbor establishment, maintenance, and demolition

 DBD: database description message for reliable database synchronization

 LSU: link-state update message used to send update entries to the database

 LSR: link-state request message, which is used to implement the request for database entries

 LSAck: link-state acknowledgement message, which is used to realize the acknowledgement of LSU and LSR messages, and to achieve the reliability of messages.

Transmission; what is the size of the IPv6 address space and how to express it?

The IPv6 address is represented by 128binary bits, so it is 2 to the 128th power

The representation is: the colon is divided into hexadecimal; what is the purpose of the OSPF virtual link?

The purpose of OSPF virtual links is to connect non-backbone areas to area 0. What are the special areas of OSPF?

Stub region

Totally stub region

NSSA region

Totally NSSA region

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Advanced routing switching and Security

# which layer of the OSI model does BGP belong to?

BGP is located at layer 7 of OSI and the socket is TCP 179. What is the purpose of BGP?

It is mainly used between different networks to realize the flexible control of routing. What is the internal anti-ring mechanism of BGP?

IBGP split horizontally.

It means that routes received from an internal BGP neighbor will not be sent to another IBGP neighbor again. What are the solutions for split horizon for IBGP neighbors?

# the first solution: full interconnection of IBGP neighbors

# the second solution: IBGP Alliance

# the third solution: IBGP routing reflector; how many tables does BGP contain?

# BGP neighbor Table

# BGP database

# what is the purpose of the BGP routing table QOS?

Classify the traffic in the network according to certain rules, and reserve and guarantee the bandwidth of these traffic, so as to ensure

Efficient and low-latency forwarding of interesting traffic in the network; A brief description of the contents of ASA firewall CONN table five tuples

Default rules followed when accessing between source IP address, destination IP address, source port number, destination port number, TCP/UDP protocol ASA firewall inside and outside interface

Allow outbound (outbound) connections and prohibit inbound (inbound) connections briefly describe the concept and role of the DMZ area

DMZ is known as the "zone of separation", also known as the "demilitarized zone".

Is a network area between the enterprise's internal network and the external network, where you can place servers that must be exposed, such as

Web servers, FTP servers, forums, etc. Describe the role of the following configuration commands

Asa (config) # object network inside

Asa (config-network-object) # subnet 10.1.1.0 255.255.255.0

Asa (config-network-object) # nat (inside,outside) dynamic 172.16.1.200

ASA Firewall dynamic PAT brief introduction of Huawei Firewall default Security Zone

Untrust (untrusted Zone): the security level is 5 and is commonly used to define Internet traffic.

DMZ (demilitarized zone): security level 50, usually used to define the zone where the server is located.

Trust (trusted Zone): security level 85, which is usually used to define the zone in which the intranet is located.

Local (local zone): security level 100. this area is mainly defined by the traffic initiated by the device itself, or when it arrives at the device from

Body flow. For example, Telnet, SNMP, NTP, IPsec × × and other traffic.

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"Network security"

# brief introduction of DoS × ×

DoS (denial of Service) refers to the situation in which the target system crashes, loses response, and is unable to provide services or access resources in any way.

Flood methods are more common in DoS, such as SYN Flood and Ping Flood.

SYN Flood * * uses the principle of three-way handshake of TCP protocol to send a large number of SYN with forged source IP addresses.

To a SYN, you need to allocate core memory for the connection information, put it in a semi-connection queue, and then return SYN+ACK to the source address.

And wait for the source to return ACK. Because the source address is bogus, the source never returns an ACK. If you pick up within a short time

If too many SYN are received, the semi-connection queue will overflow and the operating system will discard some connection information. Such a normal customer

The SYN request connection sent by the user will also be discarded by the server.

By sending a large number of packets to the target, Ping Flood causes the other party's network congestion and bandwidth depletion, thus unable to provide positive.

Regular service. A brief introduction to the definition of × ×

Virtual Private Network is a protected connection established between two network entities.

The two entities can then be connected directly through a point-to-point link or through an Internet. A brief introduction of asymmetric encryption algorithm

Asymmetric encryption algorithm uses two different keys, public key and private key, for encryption and decryption. Data encrypted with a key can only be used

Another key is decrypted and another key cannot be derived from another key. A brief introduction of stage 1 and stage 2 of IPSec × ×

IPSec uses ISAKMP/IKE Phase 1 to build a secure management connection, which is just a preparation.

It is not used to transmit actual data. Before configuration, it is necessary to make clear how the device implements authentication, what kind of encryption and authentication calculation to use.

Method, which DH group to use, and so on.

ISAKMP/IKE phase 2 is used to establish secure data connections, which are used to transmit real user data. Required before configuration

To specify which security protocol to use, an encryption or authentication algorithm should be used for a specific security protocol, as well as the data transmission mode (tunnel

Problems such as channel mode or transmission mode). A brief introduction to the Security Protocol of ISAKMP/IKE Phase 2

The security protocols of ISAKMP/IKE Phase 2 include AH protocol and ESP protocol.

AH protocol only implements authentication function, but there is no encryption function, while ESP protocol has both authentication function and encryption function. Brief introduction of IDS and IPS

* the detection system (Intrusion Detection System, IDS) discovers the * * behavior (alarm) but does not carry out the corresponding

Deal with it.

* the defense system (Intrusion Prevention System, IPS) discovers the * * behavior and defends it accordingly.

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"Management and maintenance of CVM"

# create a new connection using nmcli And configure parameters such as static IP address nmcli connection add con-name "connection name" ifname "interface name" type ethernetnmcli connection modify "connection name" ipv4.method manual ipv4.address "IP address / mask length default

Identify the gateway "

Nmcli connection modify "connection name" ipv4.dns DNS server address connection.autoconnect yesnmcli connection up "connection name" briefly describes the use of the Linux directory /, / boot, / home, / root, / bin, / dev, / etc

/: the root directory of the entire Linux file system

/ boot: stores files such as system kernel, startup menu configuration, etc.

/ home: the default home directory for ordinary users (subdirectory with the same name)

/ root: administrator's home directory

/ bin, / sbin: store system commands and executable programs

/ dev: store various device files

/ etc: store various system configurations, system service profiles using Linux command line wildcards,? The role of

Any number of arbitrary characters

A single character specifies the available yum software source vim / etc/yum.conf for CentOS series Linux hosts

.. ..

Gpgcheck = 0 / / disable software signature checking

Yum-config-manager-URL URL of add-repo software source / / add new configuration yum repolist / / confirm how the warehouse list sets document ownership and access

Set document attribution: chown-R owner: generic group document... chown-R subordinate master document... chown-R: generic group document.

Set document permissions:

The chmod-R ugoa+-=rwx documentation outlines the process of deploying a vsftpd server on a CentOS series Linux host

1) install the package yum-y install vsftpd

2) configuration

Useradd username / / add login account for FTP user passwd username / / set login password for user

3) start the server

Systemctl restart vsftpd / / start the service program systemctl enable vsftpd / / set this service to run automatically after boot what is the RAID array, and the comparison of the characteristics of RAID0, RAID1, RAID10, RAID5 and RAID6

RAID0: stripe mode with at least 2 disks to improve efficiency through concurrent read and write

RAID1: mirror mode, with at least 2 disks. Improve the reliability of disk devices through mirror backup.

RAID10: stripe + mirror mode, equivalent to RAID1+RAID0, with at least 4 disks, with higher reading and writing efficiency and reliability

RAID5: cost-effective mode, with at least 3 disks, of which 1 disk capacity is used to store recovery check data

RAID6: equivalent to the extended version of RAID5, with at least 4 disks, of which 2 disks are used to store recovery verification data and quickly add new virtual hosts when configuring httpd web servers

1) create a separate configuration file for each virtual host, put it in the / etc/httpd/conf.d/ directory, and configure the file name

It ends with. Conf

2) configure.. .. Section tags, where statements are used

ServerName specifies the site name and uses DocumentRoot to specify the web page directory

3) then restart the difference between httpd service dynamic web pages and static web pages, aiming at the conditions that httpd platform needs to support PHP programs.

Static web page: the web page file accessed by the browser is the web page file provided by the server

Dynamic web page: the web page file accessed by the browser is dynamically generated by the program specified by the server.

Support for PHP programs: installing httpd and php packages briefly describes the process of deploying an enterprise's website to Aliyun ECS

ECS is Aliyun's elastic computing service, which is commonly referred to as a cloud server.

Cloud process on a website based on ECS CVM:

1) sign up for Aliyun account

2) choose and purchase a foreign ECS server, charge for time or usage, and configure security group policy to open port 80.

3) choose and purchase a website domain name, and set the resolution target to the public network IP address of the purchased ECS

4) complete the website filing (optional)

5) prepare the documents of the enterprise's website and upload them to the Web directory of the ECS server

6) visit the corporate website through the selected domain name from the Internet

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