ffsshhttiikk What I do
- Configure and manage network switches
- Implement VLANs and trunking
- Configure spanning tree protocols
- Set up switch stacking and stacking
- Manage VLAN routing (SVI)
- Implement port security
- Configure switch monitoring
When to use me
Use me when:
- Designing local area networks
- Configuring access/aggregation switches
- Implementing network segmentation
- Troubleshooting connectivity issues
- Setting up switch infrastructure
Key Concepts
Layer 2 Switching
Switches operate at Layer 2, forwarding based on MAC addresses:
┌─────────────────────────────────────┐
│ Switch Forwarding │
├─────────────────────────────────────┤
│ MAC Address Table (CAM Table) │
│ Port 1: aa:bb:cc:dd:ee:ff │
│ Port 2: 11:22:33:44:55:66 │
│ Port 3: aa:bb:cc:dd:ee:11 │
└─────────────────────────────────────┘
Frames forwarded based on:
- Destination MAC known → Forward to port
- Unknown → Flood to all ports
- Broadcast → Flood to all ports
VLAN Configuration
! Create VLANs
vlan 10
name Data
vlan 20
name Voice
vlan 99
name Management
! Assign ports to VLANs
interface GigabitEthernet0/1
switchport mode access
switchport access vlan 10
spanning-tree portfast
! Trunk port
interface GigabitEthernet0/24
switchport trunk encapsulation dot1q
switchport mode trunk
switchport trunk allowed vlan 10,20,99
Spanning Tree Protocol
- STP: 802.1D, 50-second convergence
- RSTP: 802.1w, rapid convergence
- MSTP: 802.1s, multiple spanning trees
- PVST+: Per-VLAN STP (Cisco)
Switch Features
- Port Security: Limit MAC addresses
- DHCP Snooping: Prevent rogue servers
- ARP Inspection: Prevent ARP spoofing
- Storm Control: Broadcast suppression
- QoS: Traffic prioritization