Cisco Fundamental: Dasar Konfigurasi Router & Switch Cisco untuk Pemula

Cisco Router dan Switch Catalyst memiliki perbedaan mendasar dalam cara konfigurasi. Router bekerja di Layer 3 (Network Layer) untuk routing antar jaringan, sedangkan Switch Catalyst bekerja di Layer 2 (Data Link Layer) untuk switching dalam satu jaringan lokal. Artikel ini akan menjelaskan perbedaan konfigurasi dasar antara Router Cisco dan Switch Catalyst secara detail dan praktis.

Tabel Perbandingan Cepat

Fitur	Router Cisco	Switch Catalyst
Layer OSI	Layer 3 (Network)	Layer 2 (Data Link) / Layer 3 (untuk Switch Multilayer)
Fungsi Utama	Routing antar jaringan berbeda	Switching dalam satu jaringan (VLAN)
Interface IP	Langsung di interface fisik	Di SVI (Switched Virtual Interface / VLAN)
VLAN Support	Tidak ada (kecuali sub-interface)	Full support (create, assign, trunk)
Port Mode	Tidak ada mode access/trunk	Access mode & Trunk mode
VTY Lines	Biasanya 0-4 (5 session)	Bisa 0-4 atau 0-15 (16 session)

1. Setting Hostname

🔵 Router Cisco

Router> enable
Router# configure terminal
Router(config)# hostname R1
R1(config)# end
R1#

Catatan: Prompt berubah dari Router# menjadi R1#

🟢 Switch Catalyst

Switch> enable
Switch# configure terminal
Switch(config)# hostname SW1
SW1(config)# end
SW1#

Catatan: Prompt berubah dari Switch# menjadi SW1#

✅ SAMA: Perintah hostname identik untuk Router dan Switch

2. Setting IP Address

🔵 Router Cisco

IP Address di Interface Fisik:

R1(config)# interface gigabitEthernet 0/0
R1(config-if)# ip address 192.168.10.1 255.255.255.0
R1(config-if)# no shutdown
R1(config-if)# description LAN-Office
R1(config-if)# exit

Verifikasi:

R1# show ip interface brief

Interface        IP-Address      OK? Method Status                Protocol
GigabitEthernet0/0 192.168.10.1   YES manual up                    up

💡 Penjelasan:

• IP langsung di interface fisik (Gi0/0, Gi0/1, dll)
• Setiap interface bisa punya IP berbeda
• no shutdown wajib untuk aktifkan interface
• Router default: semua interface dalam status shutdown

🟢 Switch Catalyst

IP Address di VLAN Interface (SVI):

SW1(config)# interface vlan 1
SW1(config-if)# ip address 192.168.10.2 255.255.255.0
SW1(config-if)# no shutdown
SW1(config-if)# description Management-VLAN
SW1(config-if)# exit
SW1(config)# ip default-gateway 192.168.10.1

Verifikasi:

SW1# show ip interface brief

Interface        IP-Address      OK? Method Status                Protocol
Vlan1            192.168.10.2    YES manual up                    up

💡 Penjelasan:

• IP di SVI (Switched Virtual Interface), bukan interface fisik
• Biasanya menggunakan VLAN 1 untuk management
• ip default-gateway diperlukan untuk remote access dari jaringan lain
• Switch default: VLAN 1 dalam status shutdown

⚠️ PERBEDAAN:

• Router: IP di interface fisik (GigabitEthernet 0/0)
• Switch: IP di VLAN interface (interface vlan 1) + butuh default-gateway

3. Konfigurasi VLAN

🔵 Router Cisco

Router Tidak Punya VLAN Native

Router bisa menggunakan Sub-Interface untuk Router-on-a-Stick (inter-VLAN routing):

R1(config)# interface gigabitEthernet 0/0.10
R1(config-subif)# encapsulation dot1Q 10
R1(config-subif)# ip address 192.168.10.1 255.255.255.0
R1(config-subif)# exit

R1(config)# interface gigabitEthernet 0/0.20
R1(config-subif)# encapsulation dot1Q 20
R1(config-subif)# ip address 192.168.20.1 255.255.255.0
R1(config-subif)# exit

⚠️ Catatan: Sub-interface hanya untuk inter-VLAN routing, bukan untuk membuat VLAN!

🟢 Switch Catalyst

Membuat VLAN:

SW1(config)# vlan 10
SW1(config-vlan)# name IT-Department
SW1(config-vlan)# exit

SW1(config)# vlan 20
SW1(config-vlan)# name Finance
SW1(config-vlan)# exit

SW1(config)# vlan 30
SW1(config-vlan)# name HR-Department
SW1(config-vlan)# exit

Verifikasi VLAN:

SW1# show vlan brief

VLAN Name                             Status    Ports
---- -------------------------------- --------- ----------------
1    default                          active    Fa0/1-24, Gi0/1-2
10   IT-Department                    active    
20   Finance                          active    
30   HR-Department                    active

Konfigurasi IP untuk VLAN tertentu:

SW1(config)# interface vlan 10
SW1(config-if)# ip address 192.168.10.254 255.255.255.0
SW1(config-if)# no shutdown
SW1(config-if)# exit

⚠️ PERBEDAAN:

• Router: Tidak bisa membuat VLAN, hanya bisa routing antar VLAN via sub-interface
• Switch: Full support membuat, assign, dan manage VLAN

4. Mode Access (untuk End Device)

🔵 Router Cisco

Tidak Ada Mode Access

Interface router tidak mengenal konsep access mode atau trunk mode. Interface router bekerja di Layer 3.

! Router interface hanya menerima traffic
! tanpa VLAN tagging (untagged)

R1(config)# interface gigabitEthernet 0/0
R1(config-if)# ip address 192.168.10.1 255.255.255.0
R1(config-if)# no shutdown

🟢 Switch Catalyst

Access Mode untuk Komputer/Device:

! Port untuk komputer user IT Department
SW1(config)# interface fastEthernet 0/1
SW1(config-if)# switchport mode access
SW1(config-if)# switchport access vlan 10
SW1(config-if)# description PC-IT-User01
SW1(config-if)# spanning-tree portfast
SW1(config-if)# exit

! Port untuk komputer user Finance
SW1(config)# interface fastEthernet 0/2
SW1(config-if)# switchport mode access
SW1(config-if)# switchport access vlan 20
SW1(config-if)# description PC-Finance-User01
SW1(config-if)# spanning-tree portfast
SW1(config-if)# exit

Assign Multiple Ports sekaligus:

SW1(config)# interface range fastEthernet 0/3-10
SW1(config-if-range)# switchport mode access
SW1(config-if-range)# switchport access vlan 10
SW1(config-if-range)# spanning-tree portfast
SW1(config-if-range)# exit

Verifikasi:

SW1# show interfaces fastEthernet 0/1 switchport

Name: Fa0/1
Switchport: Enabled
Administrative Mode: access
Operational Mode: access
Access Mode VLAN: 10 (IT-Department)

💡 Penjelasan:

• switchport mode access = port untuk end device (PC, printer, server)
• switchport access vlan 10 = assign ke VLAN 10
• spanning-tree portfast = skip STP delay (opsional, untuk PC)
• Traffic keluar port ini untagged (tanpa VLAN ID)

5. Mode Trunk (untuk Switch-to-Switch atau Switch-to-Router)

🔵 Router Cisco

Interface ke Switch (untuk inter-VLAN routing):

! Interface utama tetap up (no IP)
R1(config)# interface gigabitEthernet 0/0
R1(config-if)# no shutdown
R1(config-if)# exit

! Sub-interface untuk VLAN 10
R1(config)# interface gigabitEthernet 0/0.10
R1(config-subif)# encapsulation dot1Q 10
R1(config-subif)# ip address 192.168.10.1 255.255.255.0
R1(config-subif)# exit

! Sub-interface untuk VLAN 20
R1(config)# interface gigabitEthernet 0/0.20
R1(config-subif)# encapsulation dot1Q 20
R1(config-subif)# ip address 192.168.20.1 255.255.255.0
R1(config-subif)# exit

💡 Penjelasan:

• Router menerima traffic tagged dari switch trunk port
• encapsulation dot1Q = protokol tagging VLAN (IEEE 802.1Q)
• Interface fisik (Gi0/0) harus no shutdown tanpa IP
• Sub-interface (.10, .20) yang punya IP

🟢 Switch Catalyst

Trunk ke Switch Lain:

! Trunk port ke switch lain
SW1(config)# interface gigabitEthernet 0/1
SW1(config-if)# switchport mode trunk
SW1(config-if)# switchport trunk allowed vlan 10,20,30
SW1(config-if)# switchport trunk native vlan 99
SW1(config-if)# description Trunk-to-SW2
SW1(config-if)# exit

Trunk ke Router (untuk inter-VLAN routing):

! Trunk port ke router
SW1(config)# interface gigabitEthernet 0/2
SW1(config-if)# switchport mode trunk
SW1(config-if)# switchport trunk allowed vlan 10,20,30
SW1(config-if)# description Trunk-to-Router
SW1(config-if)# exit

Verifikasi Trunk:

SW1# show interfaces trunk

Port        Mode         Encapsulation  Status        Native vlan
Gi0/1       on           802.1q         trunking      99
Gi0/2       on           802.1q         trunking      1

Port        Vlans allowed on trunk
Gi0/1       10,20,30
Gi0/2       10,20,30

💡 Penjelasan:

• switchport mode trunk = mode untuk koneksi switch-to-switch atau switch-to-router
• allowed vlan = VLAN mana saja yang boleh lewat trunk ini
• native vlan 99 = VLAN untuk untagged traffic (best practice: ubah dari default)
• Traffic keluar port ini tagged (dengan VLAN ID)

⚠️ PERBEDAAN:

• Router: Pakai sub-interface dengan encapsulation dot1Q (menerima VLAN tagged traffic)
• Switch: Pakai switchport mode trunk (mengirim VLAN tagged traffic)

6. SSH Configuration (VTY Lines)

🔵 Router Cisco

VTY 0-4 (5 concurrent sessions):

! Step 1: Set hostname & domain
R1(config)# hostname R1
R1(config)# ip domain-name lab.local

! Step 2: Buat user login
R1(config)# username admin privilege 15 secret Cisco@123

! Step 3: Generate RSA key
R1(config)# crypto key generate rsa
How many bits in the modulus [512]: 2048

! Step 4: Enable SSH version 2
R1(config)# ip ssh version 2
R1(config)# ip ssh time-out 60
R1(config)# ip ssh authentication-retries 3

! Step 5: Configure VTY lines 0-4
R1(config)# line vty 0 4
R1(config-line)# transport input ssh
R1(config-line)# login local
R1(config-line)# exec-timeout 5 0
R1(config-line)# exit

💡 VTY 0-4 = 5 Sessions

• Maksimal 5 user SSH secara bersamaan
• Cocok untuk router kecil dengan admin sedikit
• Session 0, 1, 2, 3, 4

🟢 Switch Catalyst

VTY 0-15 (16 concurrent sessions):

! Step 1: Set hostname & domain
SW1(config)# hostname SW1
SW1(config)# ip domain-name lab.local

! Step 2: Buat user login
SW1(config)# username admin privilege 15 secret Cisco@123

! Step 3: Generate RSA key
SW1(config)# crypto key generate rsa
How many bits in the modulus [512]: 2048

! Step 4: Enable SSH version 2
SW1(config)# ip ssh version 2
SW1(config)# ip ssh time-out 60
SW1(config)# ip ssh authentication-retries 3

! Step 5: Configure VTY lines 0-15
SW1(config)# line vty 0 15
SW1(config-line)# transport input ssh
SW1(config-line)# login local
SW1(config-line)# exec-timeout 10 0
SW1(config-line)# exit

💡 VTY 0-15 = 16 Sessions

• Maksimal 16 user SSH secara bersamaan
• Cocok untuk switch besar dengan banyak admin
• Session 0, 1, 2, ..., 14, 15

⚠️ PERBEDAAN VTY:

• Router: line vty 0 4 = 5 sessions concurrent
• Switch: line vty 0 15 = 16 sessions concurrent
• Alasan: Switch biasanya dikelola oleh lebih banyak admin (Network Operations Center)

7. Verifikasi Konfigurasi

Perintah	Router	Switch
show running-config	✅	✅
show ip interface brief	✅ (physical interfaces)	✅ (VLAN interfaces)
show vlan brief	❌ (tidak ada)	✅
show interfaces trunk	❌ (tidak ada)	✅
show ip ssh	✅	✅
show interfaces switchport	❌ (tidak ada)	✅

8. Save Configuration

✅ SAMA untuk Router dan Switch:

! Method 1:
write memory

! Method 2:
copy running-config startup-config

! Method 3 (shortcut):
wr

Ringkasan Perbedaan

Aspek	Router Cisco	Switch Catalyst
1. Hostname	SAMA: hostname [nama]
2. IP Address	Di interface fisik int gi0/0	Di VLAN interface int vlan 1 + ip default-gateway
3. VLAN	Tidak bisa buat VLAN Hanya routing via sub-interface	Full support VLAN vlan 10 name IT-Dept
4. Access Mode	❌ Tidak ada	✅ switchport mode access switchport access vlan 10
5. Trunk Mode	Sub-interface int gi0/0.10 encap dot1q 10	switchport mode trunk allowed vlan 10,20
6. SSH VTY	line vty 0 4 (5 sessions)	line vty 0 15 (16 sessions)

Contoh Konfigurasi Lengkap

🔵 Router R1 - Full Config

enable
configure terminal
!
hostname R1
ip domain-name lab.local
!
! Interface ke LAN
interface gigabitEthernet 0/0
 description LAN-Office
 ip address 192.168.10.1 255.255.255.0
 no shutdown
!
! Interface ke WAN (Internet)
interface gigabitEthernet 0/1
 description WAN-Internet
 ip address dhcp
 no shutdown
!
! User & SSH
username admin privilege 15 secret Cisco@123
crypto key generate rsa modulus 2048
ip ssh version 2
!
line vty 0 4
 transport input ssh
 login local
 exec-timeout 5 0
!
end
write memory

🟢 Switch SW1 - Full Config

enable
configure terminal
!
hostname SW1
ip domain-name lab.local
!
! Create VLANs
vlan 10
 name IT-Department
vlan 20
 name Finance
vlan 99
 name Management
!
! Management IP
interface vlan 99
 ip address 192.168.99.10 255.255.255.0
 no shutdown
!
ip default-gateway 192.168.99.1
!
! Access ports untuk PC
interface range fastEthernet 0/1-10
 switchport mode access
 switchport access vlan 10
 spanning-tree portfast
!
interface range fastEthernet 0/11-20
 switchport mode access
 switchport access vlan 20
 spanning-tree portfast
!
! Trunk ke router
interface gigabitEthernet 0/1
 switchport mode trunk
 switchport trunk allowed vlan 10,20,99
 switchport trunk native vlan 99
!
! User & SSH
username admin privilege 15 secret Cisco@123
crypto key generate rsa modulus 2048
ip ssh version 2
!
line vty 0 15
 transport input ssh
 login local
 exec-timeout 10 0
!
end
write memory

✅ Kesimpulan:

• Router: Fokus routing Layer 3, IP di interface fisik, no VLAN native, VTY 0-4
• Switch: Fokus switching Layer 2, IP di VLAN interface, full VLAN support, VTY 0-15
• Best Practice: Gunakan router untuk routing antar jaringan, switch untuk segmentasi VLAN dalam jaringan