# Cheatsheet

## Expert IT Systems and Devices (Crebo 25606)  
### Kerntaak B1-K2 – Infrastructuur

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## Basisconfiguratie

Deze instellingen voorkomen fouten, vertragingen en puntenverlies.

Router> enable  
Router# configure terminal  
Router(config)# hostname R1  
Router(config)# no ip domain-lookup  
Router(config)# service password-encryption  
Router(config)# banner motd #VERBODEN TOEGANG#  

### Interface activeren
Router(config)# interface gigabitEthernet 0/0  
Router(config-if)# ip address 192.168.1.1 255.255.255.0  
Router(config-if)# description Link naar Switch  
Router(config-if)# no shutdown  

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## 2️ Switching & VLANs (Laag 2)

### VLANs aanmaken
Switch(config)# vlan 10  
Switch(config-vlan)# name PERSONEEL  
Switch(config-vlan)# exit  
Switch(config)# vlan 20  
Switch(config-vlan)# name GASTEN  

### Access poorten
Switch(config)# interface fastEthernet 0/1  
Switch(config-if)# switchport mode access  
Switch(config-if)# switchport access vlan 10  
Switch(config-if)# no shutdown  

### Trunk poorten
Switch(config)# interface gigabitEthernet 0/1  
Switch(config-if)# switchport trunk encapsulation dot1q  
Switch(config-if)# switchport mode trunk  
Switch(config-if)# switchport trunk allowed vlan 10,20,99  
Switch(config-if)# no shutdown  

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## 3️ EtherChannel / LACP

Switch(config)# interface range g0/1 - 2  
Switch(config-if-range)# channel-group 1 mode active  
Switch(config-if-range)# no shutdown  

Switch(config)# interface port-channel 1  
Switch(config-if)# switchport mode trunk  
Switch(config-if)# switchport trunk allowed vlan 10,20  

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## 4️Routing (Laag 3)

### Router-on-a-Stick
Router(config)# interface g0/0  
Router(config-if)# no shutdown  

Router(config)# interface g0/0.10  
Router(config-subif)# encapsulation dot1q 10  
Router(config-subif)# ip address 192.168.10.1 255.255.255.0  

Router(config)# interface g0/0.20  
Router(config-subif)# encapsulation dot1q 20  
Router(config-subif)# ip address 192.168.20.1 255.255.255.0  

### Default route
Router(config)# ip route 0.0.0.0 0.0.0.0 203.0.113.1  

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## 5️Services – DHCP & NAT

### DHCP
Router(config)# ip dhcp pool LAN-10  
Router(dhcp-config)# network 192.168.10.0 255.255.255.0  
Router(dhcp-config)# default-router 192.168.10.1  
Router(dhcp-config)# dns-server 8.8.8.8  

### NAT
Router(config)# interface g0/0  
Router(config-if)# ip nat inside  

Router(config)# interface g0/1  
Router(config-if)# ip nat outside  

Router(config)# access-list 1 permit 192.168.10.0 0.0.0.255  

Router(config)# ip nat inside source list 1 interface g0/1 overload  

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## 6️Beveiliging – SSH & ACL

### SSH
Router(config)# hostname R1  
Router(config)# ip domain-name examen.local  
Router(config)# crypto key generate rsa  
Router(config)# username beheerder secret Cisco123  

Router(config)# line vty 0 4  
Router(config-line)# transport input ssh  
Router(config-line)# login local  

### ACL
Router(config)# access-list 100 deny icmp 192.168.10.0 0.0.0.255 host 192.168.20.50  
Router(config)# access-list 100 permit ip any any  

Router(config)# interface g0/0.10  
Router(config-subif)# ip access-group 100 in  

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## 7️ Troubleshooting

show ip interface brief  
show vlan brief  
show ip route  
show run  
show ip nat translations  
show etherchannel summary  

### Testen
ping 192.168.20.1  
tracert 8.8.8.8