updated summary page and added cli examples

2025-01-29 16:33:31 -06:00
parent 8e7c16e81b
commit 698390d976
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 # Cisco IOS Command Reference Sheet
 ## Basic Device Access
 ```cisco
 # Access Modes
 enable                      # Privileged EXEC Mode (User → Privileged)
 configure terminal          # Global Configuration Mode (Privileged → Global)
 end                        # Return to Privileged EXEC Mode
 exit                       # Exit one level back
 # Basic Show Commands
 show running-config        # Current configuration
 show startup-config        # Saved configuration
 show version              # IOS version and hardware info
 show flash:               # Contents of flash memory
 show history              # Previously used commands
 # Configuration Management
 write memory              # Save configuration
 copy running-config startup-config  # Save configuration (alternative)
 erase startup-config      # Erase saved configuration
 reload                    # Restart device
 ```
 ## Device Configuration
 ```cisco
 # System Settings
 hostname DEVICE_NAME
 service password-encryption    # Encrypt plaintext passwords
 no ip domain-lookup           # Disable DNS lookup
 banner motd #MESSAGE#         # Set login banner
 # Password Configuration
 enable secret PASSWORD        # Encrypted privileged mode password
 enable password PASSWORD      # Plaintext privileged mode password
 # Console Settings
 line console 0
 password PASSWORD
 login
 logging synchronous         # Prevent command interruption by logs
 # SSH Configuration
 ip domain-name DOMAIN
 crypto key generate rsa modulus 2048
 username ADMIN privilege 15 secret PASSWORD
 line vty 0 15
 transport input ssh
 login local
 ```
 ## Interface Configuration
 ```cisco
 # Basic Interface Commands
 interface GigabitEthernet0/0
 description LINK_DESCRIPTION
 ip address 192.168.1.1 255.255.255.0
 no shutdown
 duplex {auto|full|half}
 speed {auto|10|100|1000}
 mtu 1500
 # Interface Status Commands
 show ip interface brief       # Quick interface status
 show interfaces              # Detailed interface statistics
 show interfaces description  # Interface descriptions
 show interfaces status       # L1/L2 interface status
 show controllers             # Interface hardware status
 # Interface Range Configuration
 interface range g0/0 - 3      # Configure multiple interfaces
 interface range g0/0, g0/2    # Select specific interfaces
 default interface g0/0        # Reset interface configuration
 ```
 ## Layer 2 Switching
 ```cisco
 # VLAN Configuration
 vlan 10
 name DEPARTMENT
 show vlan brief
 show vlan id 10
 # Access Port Configuration
 interface g0/1
 switchport mode access
 switchport access vlan 10
 switchport port-security
 switchport port-security maximum 2
 switchport port-security mac-address sticky
 # Trunk Configuration
 interface g0/1
 switchport mode trunk
 switchport trunk allowed vlan 10,20,30
 switchport trunk native vlan 999
 switchport nonegotiate      # Disable DTP
 # VTP Configuration
 vtp mode {server|client|transparent}
 vtp domain DOMAIN_NAME
 vtp version {1|2|3}
 show vtp status
 ```
 ## Spanning Tree Protocol
 ```cisco
 # Global STP Commands
 spanning-tree mode {pvst|rapid-pvst|mst}
 spanning-tree extend system-id
 show spanning-tree
 show spanning-tree summary
 # VLAN STP Configuration
 spanning-tree vlan 1 root primary
 spanning-tree vlan 1 root secondary
 spanning-tree vlan 1 priority 24576
 # Interface STP Configuration
 interface g0/1
 spanning-tree portfast
 spanning-tree bpduguard enable
 spanning-tree guard root
 spanning-tree cost 100
 spanning-tree port-priority 64
 ```
 ## EtherChannel
 ```cisco
 # LACP Configuration
 interface range g0/1-2
 channel-group 1 mode active     # LACP active
 channel-group 1 mode passive    # LACP passive
 # PAgP Configuration
 interface range g0/1-2
 channel-group 1 mode desirable  # PAgP desirable
 channel-group 1 mode auto       # PAgP auto
 # Static Configuration
 interface range g0/1-2
 channel-group 1 mode on         # Force channel without protocol
 # Verification Commands
 show etherchannel summary
 show etherchannel port-channel
 show etherchannel load-balance
 ```
 ## Layer 3 Routing
 ```cisco
 # Basic Routing Commands
 ip routing                      # Enable routing on L3 switch
 show ip route
 show ip protocols
 # Static Routes
 ip route 0.0.0.0 0.0.0.0 NEXT_HOP    # Default route
 ip route NETWORK MASK NEXT_HOP        # Static route
 ip route NETWORK MASK Null0           # Null route
 # OSPF Configuration
 router ospf 1
 router-id 1.1.1.1
 network 192.168.1.0 0.0.0.255 area 0
 default-information originate
 passive-interface default
 no passive-interface g0/1
 interface g0/1
 ip ospf 1 area 0
 ip ospf cost 100
 ip ospf priority 255
 ```
 ## NAT & PAT
 ```cisco
 # Static NAT
 ip nat inside source static LOCAL_IP GLOBAL_IP
 # Dynamic NAT
 ip nat pool NAT_POOL 200.1.1.1 200.1.1.10 netmask 255.255.255.0
 ip nat inside source list 1 pool NAT_POOL
 # PAT (NAT Overload)
 access-list 1 permit 192.168.1.0 0.0.0.255
 ip nat inside source list 1 interface g0/1 overload
 # NAT Interface Configuration
 interface g0/0
 ip nat inside
 interface g0/1
 ip nat outside
 # Verification
 show ip nat translations
 show ip nat statistics
 ```
 ## Network Services
 ```cisco
 # DHCP Server
 ip dhcp excluded-address 192.168.1.1 192.168.1.10
 ip dhcp pool POOL_NAME
 network 192.168.1.0 255.255.255.0
 default-router 192.168.1.1
 dns-server 8.8.8.8
 lease 7
 # DHCP Relay
 interface g0/1
 ip helper-address DHCP_SERVER_IP
 # NTP Configuration
 ntp server IP_ADDRESS
 ntp master
 ntp authenticate
 ntp trusted-key 1
 ntp authentication-key 1 md5 PASSWORD
 # Syslog
 logging host IP_ADDRESS
 logging trap debugging
 logging facility local7
 ```
 ## Monitoring & Troubleshooting
 ```cisco
 # Discovery Protocols
 show cdp neighbors detail
 show lldp neighbors detail
 show cdp interface
 # Debug Commands
 debug ip ospf packet
 debug ip ospf hello
 no debug all              # Disable all debugging
 # Interface Diagnostics
 show interfaces counters
 show interfaces counters errors
 show controllers ethernet-controller
 show processes cpu
 show memory statistics
 # Logging
 show logging
 show logging history
 terminal monitor          # Enable logging in SSH/Telnet
 ```
 ---
 ## 1. Basic Device Configuration
 ### 1.1 Initial Device Access
 - **Enable Mode**: Access privileged EXEC mode
  ```cisco
  Router> enable
  Router# 
  ```
 - **Configuration Mode**: Enter global configuration mode
  ```cisco
  Router# configure terminal
  Router(config)#
  ```
 - **Basic Device Security**:
  ```cisco
  enable password boson      # Basic password (not encrypted)
  enable secret boson       # Encrypted password (preferred)
  ```
 ### 1.2 Device Management
 - **Hostname Configuration**:
  ```cisco
  hostname R1
  ```
 - **Interface Configuration**:
  ```cisco
  interface GigabitEthernet 0/0
  description Connection to SW1
  ip address 192.168.1.1 255.255.255.0
  no shutdown
  ```
 - **Saving Configuration**:
  ```cisco
  write memory    # or 'wr'
  copy running-config startup-config
  ```
 ## 2. Interface Configuration
 ### 2.1 IPv4 Configuration
 ```cisco
 ## conf ipv4 ##
 en
 conf t
 int f0/1
 ip addr 192.168.1.1 255.255.255.0
 no shut
 end
 wr
 ```
 - Purpose: Configures basic IPv4 addressing on an interface
 - Key Components:
  - `ip addr`: Assigns IP address and subnet mask
  - `no shut`: Enables the interface
  - `wr`: Saves configuration to NVRAM
 ### 2.2 IPv6 Configuration
 ```cisco
 ## conf ipv6 ##
 en
 conf t
 ipv6 unicast-routing
 int f0/1 
 ipv6 addr 2001:db8:3445:abde::1/64
 no shut
 end wr
 ```
 - Purpose: Enables and configures IPv6 on an interface
 - Key Components:
  - `ipv6 unicast-routing`: Enables IPv6 routing globally
  - `ipv6 addr`: Assigns IPv6 address with prefix length
 ## 3. VLAN Configuration
 ### 3.1 Basic VLAN Setup
 ```cisco
 ## create vlan and conf name ##
 en
 conf t
 vlan 10
 name Sales
 ## conf int as switchport for vlan ##
 int f0/1
 sw mo ac
 switchport access vlan 10
 ```
 - Purpose: Creates and assigns VLANs to interfaces
 - Key Concepts:
  - VLANs segment broadcast domains
  - Access ports belong to single VLAN
  - Trunk ports carry multiple VLAN traffic
 ### 3.2 VLAN Trunking
 ```cisco
 ## conf SW for 802.1q and trunking mode ##
 en
 conf t
 int f0/1
 sw tr enc dot1q
 sw mo tr
 ```
 - Purpose: Configures trunk links between switches
 - Features:
  - 802.1Q tagging for VLAN identification
  - Supports multiple VLANs over single link
  - Can specify allowed VLANs
 ### 3.3 Inter-VLAN Routing
 ```cisco
 ## create a subint for vlan 10 ##
 en
 conf t
 int f0/0.10
 enc dot1q 10
 ip addr 192.168.10.1 255.255.255.192
 ```
 - Purpose: Enables routing between VLANs
 - Methods:
  - Router-on-a-stick (shown above)
  - Layer 3 switch routing
  - Multiple physical interfaces
 ## 4. Spanning Tree Protocol (STP)
 ### 4.1 Basic STP Configuration
 ```cisco
 ## conf vlan pvst (Rapid-PVST+) ##
 en
 conf t
 spanning-tree vlan 100 priority root
 ## conf portfast on int f0/1 ##
 int f0/1
 spanning-tree portfast
 ```
 - Purpose: Prevents layer 2 loops
 - Key Features:
  - Root bridge election
  - Loop prevention
  - Convergence optimization
 ## 5. EtherChannel Configuration
 ### 5.1 Layer 2 EtherChannel
 ```cisco
 ## layer 2 etherchannel ##
 en
 conf t 
 int r f0/1 - 4
 channel-group 1 mode active
 ```
 - Purpose: Combines multiple physical links into one logical link
 - Benefits:
  - Increased bandwidth
  - Redundancy
  - Load balancing
 ## 6. Security Features
 ### 6.1 SSH Configuration
 ```cisco
 ## conf ssh ##
 en
 conf t
 line vty 0 15
 no password sharedpassword
 login local
 transport input ssh  # enable ssh only
 ## ssh generate rsa key ##
 crypto key generate rsa
 ```
 - Purpose: Secure remote access
 - Key Components:
  - RSA key generation
  - VTY line configuration
  - Authentication methods
 ### 6.2 Port Security
 ```cisco
 ## Basic Port Security ##
 en
 conf t
 int f0/1
 switchport port-security
 switchport port-security maximum 2
 switchport port-security mac-address sticky
 ```
 - Purpose: Prevents unauthorized access at switch ports
 - Features:
  - MAC address limiting
  - Violation actions
  - Sticky learning
 ## 7. Routing Protocols
 ### 7.1 OSPF Configuration
 ```cisco
 ## conf OSPF process and area on int ##
 en
 conf t
 int f0/1
 ip ospf 10 area 0
 ## conf network to operate in OSPF area 0 ##
 router ospf 10
 network 203.0.113.0 0.0.0.7 area 0
 ```
 - Purpose: Dynamic routing protocol for internal networks
 - Key Concepts:
  - Area-based hierarchy
  - Link-state protocol
  - Dijkstra's algorithm for path selection
 - Verification Commands:
  ```cisco
  show ip ospf
  show ip ospf neighbor
  show ip route ospf
  ```
 ### 7.2 Static Routing
 ```cisco
 ## conf a default route by int ##
 ip route 0.0.0.0 0.0.0.0 int f0/1
 ## conf a default route by next int ip addr ##
 ip route 0.0.0.0 0.0.0.0 203.0.113.1
 ```
 - Purpose: Manually configured routes
 - Use Cases:
  - Default routes
  - Stub networks
  - Small network designs
 ## 8. Network Address Translation (NAT)
 ### 8.1 Static NAT
 ```cisco
 ## implement static nat on router ##
 en
 conf t
 int g0/0
 ip nat outside
 int g0/1
 ip nat inside
 exit
 ip nat inside source static 192.168.100.38 192.0.2.9
 ```
 - Purpose: One-to-one mapping of private to public addresses
 - Verification:
  ```cisco
  show ip nat translations
  show ip nat statistics
  ```
 ### 8.2 PAT (NAT Overload)
 ```cisco
 ## conf pat aka nat overload ##
 en
 conf t
 access-list 1 permit 192.168.100.32 0.0.0.31
 int g0/1
 ip nat inside
 int g0/0
 ip nat outside
 ip nat inside source list 1 interface g0/0 overload
 ```
 - Purpose: Many-to-one address translation
 - Benefits:
  - Conserves public IP addresses
  - Common in home/small business networks
 ## 9. Network Services
 ### 9.1 DHCP Configuration
 ```cisco
 ## conf dhcp server ##
 en
 conf t
 service dhcp
 ip dhcp excluded-address 172.16.10.17
 ip dhcp pool pool_one
 network 172.16.10.16 255.255.255.240
 default-router 172.16.10.17
 ## conf dhcp relay ##
 int f0/1
 ip helper 203.0.113.1
 ```
 - Purpose: Automatic IP address assignment
 - Components:
  - DHCP pool definition
  - Excluded addresses
  - Default gateway
  - DHCP relay for remote networks
 ### 9.2 NTP Configuration
 ```cisco
 ## conf ntp server ##
 en
 conf t
 ntp master
 ## conf ntp client ##
 ntp authenticate
 ntp authentication-key 1 md5 80$0n!
 ntp trusted-key 1
 ntp server 203.0.113.5 key 1
 ```
 - Purpose: Network time synchronization
 - Security Features:
  - Authentication
  - Access control lists
  - Trusted keys
 ### 9.3 DNS Configuration
 ```cisco
 ## enable dns server ##
 en
 conf t
 ip dns server
 ## conf dns host table ##
 ip host www 192.168.52.44
 ```
 - Purpose: Domain name resolution
 - Features:
  - Local DNS server
  - Static host mappings
  - DNS forwarding
 ## 10. High Availability
 ### 10.1 HSRP Configuration
 ```cisco
 ## conf hsrp ##
 en
 conf t
 int f0/0
 standby 1 ip 192.168.1.1
 standby 1 priority 110
 standby 1 preempt
 ```
 - Purpose: Router redundancy protocol
 - Features:
  - Virtual IP address
  - Priority-based active router selection
  - Preemption capability
 ### 10.2 VRRP Configuration
 ```cisco
 ## conf vrrp ##
 en
 conf t
 int vlan 100
 vrrp 1 ip 192.168.100.1
 vrrp 1 priority 110
 ```
 - Purpose: Alternative to HSRP
 - Key Differences:
  - Industry standard (vs. Cisco proprietary HSRP)
  - Similar functionality
 ## 11. Troubleshooting
 ### 11.1 Interface Status
 ```cisco
 ## check all int ##
 show ip interface brief
 show interface status    # switches only
 ## check one int ##
 show ip interface f0/1
 ```
 - Purpose: Verify interface operation
 - Key Information:
  - Line/protocol status
  - IP addressing
  - Interface errors
 ### 11.2 Protocol Debugging
 ```cisco
 ## debug ospf hello msg ##
 debug ip ospf hello
 ## show nat translations ##
 show ip nat translations
 ## show routing table ##
 show ip route
 ```
 - Purpose: Detailed protocol analysis
 - Best Practices:
  - Use specific debug commands
  - Monitor system resources
  - Clear debug when finished
 ### 11.3 Common Show Commands
 ```cisco
 show running-config
 show vlan brief
 show spanning-tree
 show etherchannel summary
 show cdp neighbors
 ```
 - Purpose: Configuration verification
 - Use Cases:
  - Troubleshooting
  - Documentation
  - Change verification
 ## 12. Best Practices
 ### 12.1 Configuration Management
 - Save configurations regularly
 - Document changes
 - Use consistent naming conventions
 - Implement secure passwords
 - Regular backups
 ### 12.2 Security Guidelines
 - Disable unused ports
 - Use secure protocols (SSH vs Telnet)
 - Implement access lists
 - Regular security audits
 - Password best practices
@@ -11,3 +11,4 @@
 - [IP Services](4-ip-services.md)
 - [Security Fundamentals](5-security-fundamentals.md)
 - [Automation and Programmability](6-automation-and-programmability.md)
 - [Command Line Examples](7-command-line-examples.md)