網路原理(一) Section 11

Application Filtering
Prevents or allows access by specific application types based on port numbers

Authentication, Authorization, and Accounting (AAA)
AAA is a way to control who is permitted to access a network (authenticate), what they can do while they are there (authorize), and what actions they perform while accessing the network (accounting).

auto secure (command)

exec timeout (command)
Exec timeouts can be configured on console, VTY, and aux ports using the exec-timeout command in line configuration mode. 

crypto key generate rsa general-keys modulus modulus-size (command)
To generate the SSH key, use the crypto key generate rsa general-keys command in global configuration mode.

endpoint security
An endpoint, or host, is an individual computer system or device that acts as a network client.

ip domain-name domain-name (command)
Ensure that the router has a unique hostname, and then configure the IP domain name of the network using the ip domain-name command in global configuration mode.

login block-for 120 attempts 3 within 60 (command)
t is possible to prevent this type of attack by blocking login attempts to the device if a set number of failures occur within a specific amount of time.

Packet Filtering
Prevents or allows access based on IP or MAC addresses

passphrase
Therefore, one method to create a strong password is to use the space bar and create a phrase made of many words. This is called a passphrase.

Personal firewalls
Host-based firewalls or personal firewalls are installed on end systems.

security passwords min-length (command) 
Additionally, to ensure that all configured passwords are a minimum of a specified length, use the security passwords min-length command in global configuration mode.

Stateful Packet Inspection (SPI)
Incoming packets must be legitimate responses to requests from internal hosts.


transport input ssh
Enable inbound SSH sessions using the line vty commands login local and transport input ssh.

URL Filtering
Prevents or allows access to websites based on specific URLs or keywords


! . U

Address Resolution Protocol (ARP)
位址解析協定(ARP) 是通過解析網路層位址來找尋資料鏈路層位址的一個在網路協定包中極其重要的網路傳輸協定。

ipconfig (host command)
查看介面卡配置

loopback address
127.0.0.1

ping (command)
ping是一種電腦網路工具，用來測試封包能否透過IP協定到達特定主機。

service password-encryption (command)
密碼加密

show cdp neighbors (IOS command)
The show cdp neighbors detail command reveals the IP address of a neighboring device.

show ip interface brief (IOS command)
The show ip interface brief output displays all interfaces on the router, the IP address assigned to each interface, if any, and the operational status of the interface.

tracert (host command) ;  traceroute (IOS command)
traceroute，現代Linux系統稱為tracepath，Windows系統稱為tracert，是一種電腦網路工具。它可顯示封包在IP網路經過的路由器的IP位址。