> ## Content Index > Fetch the complete content index at: https://www.pinglabz.com/llms.txt > Use this file to discover other available public pages before exploring further. # Configuring VLANs on Cisco Catalyst Switches - URL: https://www.pinglabz.com/configuring-standard-vlans-on-catalyst-switches/ - Published: 2024-12-23T06:56:30.000Z - Updated: 2026-07-04T23:01:38.000Z - Description: Learn how to create VLANs, assign access ports, and verify your VLAN configuration on Cisco Catalyst 9000 series switches using IOS XE 17.x. - Author: Jaime - Tags: VLAN, #Import 2026-08-01 19:54 Creating VLANs on Cisco Catalyst switches is the foundation of logical network segmentation, allowing you to isolate traffic, improve security, and optimize bandwidth allocation across your infrastructure. Whether you're building a new campus network or expanding an existing one, understanding how to create VLANs and assign ports is essential for every network engineer. If you want the bigger picture first, the [VLAN complete guide](https://www.pinglabz.com/vlans-layer-2-switching/) covers the architecture this article plugs into. ## Understanding VLAN Creation on Catalyst When you create a VLAN on a Catalyst switch, the configuration is stored in two places: the running-configuration (RAM) and the vlan.dat file (NVRAM). For standard-range VLANs (1-1005), the VLAN is automatically synchronized with vlan.dat during a reload. Understanding this behavior prevents accidental VLAN loss. ## Creating VLANs in Global Configuration Mode The standard method for creating VLANs on Catalyst 9000 series switches uses global configuration mode: ``` CORE-SW1# configure terminal CORE-SW1(config)# vlan 10 CORE-SW1(config-vlan)# name Users CORE-SW1(config-vlan)# exit CORE-SW1(config)# vlan 20 CORE-SW1(config-vlan)# name Servers CORE-SW1(config-vlan)# exit CORE-SW1(config)# vlan 30 CORE-SW1(config-vlan)# name Mgmt CORE-SW1(config-vlan)# exit CORE-SW1(config)# vlan 40 CORE-SW1(config-vlan)# name Voice CORE-SW1(config-vlan)# exit CORE-SW1(config)# vlan 50 CORE-SW1(config-vlan)# name Guest CORE-SW1(config-vlan)# exit CORE-SW1(config)# vlan 99 CORE-SW1(config-vlan)# name Native CORE-SW1(config-vlan)# exit CORE-SW1(config)# vlan 999 CORE-SW1(config-vlan)# name Parking CORE-SW1(config-vlan)# exit CORE-SW1(config)# end CORE-SW1# write memory ``` Each `vlan` command enters VLAN configuration mode where you can assign a descriptive name. The name helps administrators quickly identify the VLAN's purpose in show command output and network documentation. Without a name, VLANs appear as "VLAN####" in displays. ## Assigning Access Ports to VLANs After creating VLANs, assign physical ports to them using switchport commands. On an access port, all traffic on that port belongs to a single VLAN: ``` CORE-SW1(config)# interface GigabitEthernet 1/0/1 CORE-SW1(config-if)# switchport mode access CORE-SW1(config-if)# switchport access vlan 10 CORE-SW1(config-if)# description Users-Access-Port-1 CORE-SW1(config-if)# no shutdown CORE-SW1(config-if)# exit CORE-SW1(config)# interface GigabitEthernet 1/0/2 CORE-SW1(config-if)# switchport mode access CORE-SW1(config-if)# switchport access vlan 20 CORE-SW1(config-if)# description Servers-Access-Port-1 CORE-SW1(config-if)# no shutdown CORE-SW1(config-if)# exit ``` The `switchport mode access` command configures the port in access mode (Layer 2 only, no trunking). The `switchport access vlan` command assigns the VLAN ID to that port. All frames transmitted on this port will be tagged with VLAN 10 internally; untagged frames received on the port are assumed to belong to VLAN 10. ## Complete VLAN Configuration for ACC-SW1 Here's the full configuration for an access switch with all standard lab VLANs and port assignments: ``` ACC-SW1# configure terminal ACC-SW1(config)# vlan 10 ACC-SW1(config-vlan)# name Users ACC-SW1(config-vlan)# exit ACC-SW1(config)# vlan 20 ACC-SW1(config-vlan)# name Servers ACC-SW1(config-vlan)# exit ACC-SW1(config)# vlan 30 ACC-SW1(config-vlan)# name Mgmt ACC-SW1(config-vlan)# exit ACC-SW1(config)# vlan 40 ACC-SW1(config-vlan)# name Voice ACC-SW1(config-vlan)# exit ACC-SW1(config)# vlan 50 ACC-SW1(config-vlan)# name Guest ACC-SW1(config-vlan)# exit ACC-SW1(config)# vlan 99 ACC-SW1(config-vlan)# name Native ACC-SW1(config-vlan)# exit ACC-SW1(config)# vlan 999 ACC-SW1(config-vlan)# name Parking ACC-SW1(config-vlan)# exit ! Configure User ports ACC-SW1(config)# interface range GigabitEthernet 1/0/1-10 ACC-SW1(config-if-range)# switchport mode access ACC-SW1(config-if-range)# switchport access vlan 10 ACC-SW1(config-if-range)# description Users-Access-Ports ACC-SW1(config-if-range)# no shutdown ACC-SW1(config-if-range)# exit ! Configure Server ports ACC-SW1(config)# interface range GigabitEthernet 1/0/11-14 ACC-SW1(config-if-range)# switchport mode access ACC-SW1(config-if-range)# switchport access vlan 20 ACC-SW1(config-if-range)# description Servers-Access-Ports ACC-SW1(config-if-range)# no shutdown ACC-SW1(config-if-range)# exit ! Configure Management port ACC-SW1(config)# interface GigabitEthernet 1/0/15 ACC-SW1(config-if)# switchport mode access ACC-SW1(config-if)# switchport access vlan 30 ACC-SW1(config-if)# description Mgmt-Access-Port ACC-SW1(config-if)# no shutdown ACC-SW1(config-if)# exit ! Configure Voice ports ACC-SW1(config)# interface range GigabitEthernet 1/0/16-18 ACC-SW1(config-if-range)# switchport mode access ACC-SW1(config-if-range)# switchport access vlan 40 ACC-SW1(config-if-range)# description Voice-Access-Ports ACC-SW1(config-if-range)# no shutdown ACC-SW1(config-if-range)# exit ! Configure Guest ports ACC-SW1(config)# interface range GigabitEthernet 1/0/19-21 ACC-SW1(config-if-range)# switchport mode access ACC-SW1(config-if-range)# switchport access vlan 50 ACC-SW1(config-if-range)# description Guest-Access-Ports ACC-SW1(config-if-range)# no shutdown ACC-SW1(config-if-range)# exit ! Configure Parking (unused ports) ACC-SW1(config)# interface range GigabitEthernet 1/0/22 ACC-SW1(config-if-range)# switchport mode access ACC-SW1(config-if-range)# switchport access vlan 999 ACC-SW1(config-if-range)# description Parking-Port ACC-SW1(config-if-range)# shutdown ACC-SW1(config-if-range)# exit ACC-SW1(config)# end ACC-SW1# write memory ``` ## Verifying VLAN Configuration After configuring VLANs and ports, verify the configuration using show commands. The `show vlan brief` command displays all VLANs and their assigned ports: ``` ACC-SW1# show vlan brief VLAN Name Status Ports ---- -------------------------------- --------- ------------------------------- 1 default active Gi1/0/23,Gi1/0/24 10 Users active Gi1/0/1,Gi1/0/2,Gi1/0/3,Gi1/0/4 Gi1/0/5,Gi1/0/6,Gi1/0/7,Gi1/0/8 Gi1/0/9,Gi1/0/10 20 Servers active Gi1/0/11,Gi1/0/12,Gi1/0/13,Gi1/0/14 30 Mgmt active Gi1/0/15 40 Voice active Gi1/0/16,Gi1/0/17,Gi1/0/18 50 Guest active Gi1/0/19,Gi1/0/20,Gi1/0/21 99 Native active 999 Parking active Gi1/0/22 ``` The `show interfaces switchport` command shows detailed switchport configuration for individual ports or ranges: ``` ACC-SW1# show interfaces GigabitEthernet 1/0/1 switchport Name: Gi1/0/1 Switchport: Enabled Administrative Mode: static access Operational Mode: static access Administrative Trunking Encapsulation: dot1q Operational Trunking Encapsulation: native Negotiation of Trunking: Off Access Mode VLAN: 10 (Users) Trunking Native Mode VLAN: 1 (default) Administrative private-vlan host-association: none Administrative private-vlan mapping: none Operational private-vlan: none Trunking VLANs Enabled: All Pruning VLANs Enabled: 2-1001 Capture Mode Disabled Capture Session ID - Common Session ID: 0 Protected Port: false Unknown unicast blocked: disabled Unknown multicast blocked: disabled Appliance trust: none ``` To view multiple ports at once, use the `show interfaces` command with a range: ``` ACC-SW1# show interfaces GigabitEthernet 1/0/1-10 switchport | include Name|Access Mode VLAN Name: Gi1/0/1 Access Mode VLAN: 10 (Users) Name: Gi1/0/2 Access Mode VLAN: 10 (Users) Name: Gi1/0/3 Access Mode VLAN: 10 (Users) Name: Gi1/0/4 Access Mode VLAN: 10 (Users) Name: Gi1/0/5 Access Mode VLAN: 10 (Users) Name: Gi1/0/6 Access Mode VLAN: 10 (Users) Name: Gi1/0/7 Access Mode VLAN: 10 (Users) Name: Gi1/0/8 Access Mode VLAN: 10 (Users) Name: Gi1/0/9 Access Mode VLAN: 10 (Users) Name: Gi1/0/10 Access Mode VLAN: 10 (Users) ``` ## Verification and Troubleshooting ### Symptom: Hosts cannot ping each other on the same VLAN **Cause:** Ports may not be assigned to the same VLAN, or one port is administratively down. **Fix:** Verify port assignments with `show vlan brief`, check port status with `show interfaces status`, and confirm both ports are enabled (no shutdown). ``` ACC-SW1# show interfaces status | include Users|Gi1/0/1 Interface Name Status Vlan Duplex Speed Type Gi1/0/1 Users-Access-Port-1 connected 10 a-full a-100 10/100/1000BaseTX Gi1/0/2 Users-Access-Port-2 connected 10 a-full a-100 10/100/1000BaseTX ``` If a port shows "notconnect," the issue may be a cable problem or the connected device is down. Use `show interfaces GigabitEthernet 1/0/1` to check physical status. ### Symptom: VLAN configuration disappears after reload **Cause:** VLANs 1-1005 are stored in vlan.dat, but if vlan.dat is deleted or corrupted, only VLAN 1 survives a reload. **Fix:** Verify vlan.dat exists with `show flash:` or `dir flash:`. If missing, reconfigure VLANs and execute `write memory` to rebuild vlan.dat. For extended-range VLANs (1006-4094), always include them in running-config via `vlan database` or config mode, then copy running-config to startup-config. ``` ACC-SW1# show flash: | include vlan.dat 32 -rw- 786432 Mar 28 2026 17:42:31 +00:00 vlan.dat ``` ### Symptom: Wrong VLAN assigned to a port **Cause:** Port assignment commands were entered incorrectly or overwritten by a misconfiguration script. **Fix:** Re-enter the correct VLAN assignment for the port. The `switchport access vlan` command automatically replaces the previous assignment. ``` ACC-SW1(config)# interface GigabitEthernet 1/0/5 ACC-SW1(config-if)# switchport access vlan 20 ACC-SW1(config-if)# end ACC-SW1# show interfaces GigabitEthernet 1/0/5 switchport | include Access Mode VLAN Access Mode VLAN: 20 (Servers) ``` ## Key Takeaways - Create VLANs in global configuration mode using `vlan ` and assign a descriptive name for easy identification - Assign access ports using `switchport mode access` followed by `switchport access vlan ` - Verify VLAN configuration with `show vlan brief` to see all VLANs and their port members - Standard-range VLANs (1-1005) are automatically saved to vlan.dat; always execute `write memory` after configuration changes - Use interface ranges (e.g., `interface range Gi1/0/1-10`) to efficiently configure multiple ports with the same VLAN assignment