Switchport trunk native vlan command. VLANs can be as multitudinous as there are.

Switchport trunk native vlan command Sep 3, 2017 · The default native VLAN on an 802. Mar 17, 2023 · This post represents Part 2 of 3 of VLANs study notes for the CCNA exam. To enable trunking to a device that does not support DTP, use the switchport Feb 19, 2009 · On specific trunk ports you can simply use the “switchport trunk native vlan tag” Cisco command to achieve the same results but at the interface level. interface ethernet 1/1 switchport trunk native vlan 60 Note: The property information for this example was added in Release 9. Each step ensures smooth VLAN transitions, whether in access or trunk mode. clear vtp counters Syntax The first command disallows all traffic from indicated vlans - no type of traffic cannot traverse the trunk out of that vlan, period. It’s useful for The technique name you're looking for is 802. Jan 10, 2025 · A trunk port is a switch interface configured to carry traffic for multiple VLANs by using VLAN tags. 1Q VLAN, or, in a Virtual Fabrics context, as service or transport VF on a trunk port, matching tagged or untagged data traffic that does not match a classification rule. When VTP detects a newly enabled VLAN and the VLAN is in the allowed list for a trunk port, the trunk port automatically becomes a member of the enabled VLAN. Feb 28, 2025 · Use the switchport trunk native vlan Interface Configuration mode command to define the native VLAN for a trunk interface. It will show all the defaults in configuration, including the default setting for native VLAN on the trunk port. Understanding the difference can make the difference between complete network chaos, and just simply adding a vlan. This can be changed with “switchport trunk native vlan “vlan number” auto-auto = no trunk auto - desirable = trunk (with non negotiate enabled (default is on as seen in your output Aug 14, 2024 · Configuring the Native VLAN for Untagged Traffic Configuring a Trunk Port Because trunk ports send and receive VTP advertisements, to use VTP you must ensure that at least one trunk port is configured on the device and that this trunk port is connected to the trunk port of a second device. Procedure Jul 23, 2025 · Frames entered untagged on the trunk links are set to the native VLAN. The second interface command ("pruning") has to do with whether the vlan is eligible to be pruned. so after configuring trunk switchports and creating the VLANs on the server switch, configuring the same domain on the rest of the switches and verify they have the VLANs listed, I tried to issue switchport trunk allowed vlan command on the server switch's interfaces, then tried to verify it with show interface x/x switchport command - I still Sep 19, 2011 · I am trying show vlan command but could find there which vlan is native. Apr 24, 2009 · Hi All, this command is a little confusing to me: "switchport trunk native vlan (vlan ID)" So the way that I understand this is that if a frame comes in that is untagged without a vlan or vlan 1 that it will default to the vlan that I specify in this command. 1Q VLANs Configuring a LAN Interface as an Ethernet Access Port Configuring Access Host Ports Configuring Trunk Ports Configuring the Native VLAN for 802. Procedure To restrict the traffic a trunk carries, use the switchport trunk allowed vlan remove vlan-list interface configuration command to remove specific VLANs from the allowed list. SW3(config)#int fa0/19 SW3(config-if)#switchport trunk allowed vlan 2 Here’s the trunk information for SW3 after the changes. So the native VLAN in this case is VLAN 1. Native VLAN mismatch leads to misdirected traffic and is a security implication. Switch(config-if)#switchport mode trunk Command rejected: An interface whose trunk encapsulation is "Auto" can not be configured to "trunk" mode. 1Q trunk without disabling spanning tree on every VLAN in the network can potentially cause spanning-tree loops. Trunk ports can receive both tagged and untagged packets. Trunks will carry multiple VLANs only if they are created. Best practices would say to disable vlan 1 and use a different for native vlan as a switchport not configured will be automatically in vlan 1. 1q trunk port. . To only allow specific VLANs on the trunk, issue the vlan trunk allowed command specifying only specific VLANs. It doesn’t matter if you configure trunk ports first or assign access ports, as long as you do both. 1q tag) could jump from one vlan to a more secure vlan. Oct 29, 2007 · By default native VLAN is VLAN 1, but can be changed to any No. You can resolve this problem by first checking the trunk port on the switch using Show interface trunk command and the reconfiguring the trunk port using the switchport trunk allowed vlan command. Part… Configures the native VLAN ID for the virtual Ethernet interface. Mar 31, 2025 · The default mode for Layer 2 interfaces is switchport mode dynamic auto . The above picture shows that the trunk link is connected to port fa0/24 on both switches. As of the native vlan, it will continue to be vlan 1. However lets say your native vlan is 1 (by default). Untagged data traffic received through the trunk will be put in the native vlan. A trunk port by default is a member of all VLANs. A recommended security practice is to change the native VLAN to a different VLAN than VLAN 1. Administrators can assign any VLAN ID (other than the default VLAN 1) as the Native VLAN, based on their network requirements. Native VLANs do not tag the out going VLAN packets toward ESX NICs and if the Aug 1, 2022 · Indeed, on an access port, the access VLAN is the native VLAN, because by definition, the traffic on native VLAN is untagged which is always the case for the access VLAN on an access port. Otherwise, the device cannot receive any VTP Aug 22, 2025 · This tutorial explains VLAN configuration commands. clear vtp counters Syntax Trunk Configuration Commands Now that you have configured and verified VLANs, it is time to configure and verify VLAN trunks. Unlike access ports, which connect end devices and carry traffic for a single VLAN, trunk ports connect switches (or switch-to-router links) and forward data for multiple VLANs simultaneously. 1Q trunk or disable spanning tree on every VLAN in the network. The default mode for Layer 2 interfaces is switchport mode dynamic auto . Jun 22, 2009 · Issue the switchport trunk native vlan [vlan-id] command in order to configure the VLAN. Feb 14, 2020 · Objectives Part 1: Verify VLANs Part 2: Configure Trunks Background Trunks are required to pass VLAN information between switches. The following table describes the acceptable frame types, as well as system behavior, for tagged native VLAN, untagged native VLAN, and no native VLAN. The VLAN information is embedded into the Ethernet frames via 802. These commands help manage traffic and answer what is a switchport in complex settings. The question is when the Cisco switch is configured with the switchport trunk native vlan command it will not talk to the HP but when I remove it everything works. Use the no form of this command to restore the default native VLAN. Mar 31, 2025 · show vtp switchport mode private-vlan switchport priority extend switchport trunk vlan vlan dot1q tag native vtp (global configuration) vtp (interface configuration) vtp primary clear vtp counters To clear the VLAN Trunking Protocol (VTP) and pruning counters, use the clear vtp counters command in privileged EXEC mode. Synopsis switchport trunk native-vlan vlan_id [ctag id] no switchport Be very careful with allowed vlan, it is absolutely important that you understand the difference between allowed vlan, and allowed vlan add. The following figure shows how you can use trunk ports in the network. This command works when there are 2 Cisco switches together. io We’ll create a VLAN, assign access ports, configure the trunk, and explore the different switchport modes (trunk, access, dynamic auto, and dynamic desirable). When native VLAN and management VLAN is configured with the same VLAN ID and a new VLAN is added as trunk port, both the new VLAN and native VLAN shifts between active and suspend state for a duration of 15 seconds. Jun 30, 2024 · Configuring Native VLANs on Cisco Switches: A Step-by-Step Guide Native VLAN configuration on Cisco switches is a pivotal task for network administrators that ensures data traffic is properly managed and segmented within a switch network. Apr 7, 2008 · The link is configured as a trunk port that carries 2 Vlans. Aug 23, 2022 · 0 According to this article Cisco recommends VLAN 99 for the "native VLAN". The problem is that from a prior configuration on the port, I seem to have both switchport access and switchport trunk set (not to mention no switchport as I try to fiddle with the settings). Apr 5, 2024 · Configuring the Native VLAN for Untagged Traffic Configuring a Trunk Port Because trunk ports send and receive VTP advertisements, to use VTP you must ensure that at least one trunk port is configured on the device and that this trunk port is connected to the trunk port of a second device. The no form of the command deletes the VLAN configuration from the role. Restrictions for VLAN Trunks • Disabling spanning tree on the native VLAN of an IEEE 802. By default, VLAN 1 is used as the native VLAN, but it can be changed for security or organizational purposes. (config-data)# interface gigabitethernet 4/2 (conf-if-GE 4/2)# switchport trunk native vlan 3 I think the command, switchport native vlan 99, on an access port, will set the native VLAN to be 99 if the port becomes a trunk through either autonegotiation or if set to trunk. Jul 10, 2023 · When configuring a trunk port on a switch for inter-VLAN routing, it is recommended to configure the native VLAN to an unused VLAN in order to improve network security. This command only takes effect for interfaces that are operating in trunk mode. 1Q (dot1q) trunking between Cisco Catalyst switches that run Cisco IOS® Software. Configure the administrative mode of the trunking interface to be in trunk mode, and correct the native VLAN mismatch with the switchport trunk native vlan 99 command. Nov 22, 2010 · switchport trunk native vlan 99 switchport trunk allowed vlan 1,85,160 switchport mode trunk channel-group 2 mode desirable The port-channel2 interface is automatically created with those characteristics? From memory no i don't think it does, although i could be misremembering. 1Q trunk is the same on both ends of the trunk link. Mar 14, 2017 · Example: switchport trunk native vlan 100 - Disable DTP or negotiation on your interface trunk switchport nonegotiate - You could just allow specific vlans through your interface trunk. The native VLAN is used for untagged traffic on the trunk link. If the native VLAN on one end of the trunk is different from the native VLAN on the other end, spanning-tree loops might result. Verifying a DME Configuration The following table contains the distinguished name (DN Jul 1, 2025 · This document describes the native VLAN configuration options in a Cisco Intersight-Managed Mode environment, highlighting common scenarios. When a native VLAN is defined, the switch automatically executes the vlan trunk allowed all command to ensure that the default VLAN is allowed on the trunk. Is that correct? Even more puzzling is w To only allow specific VLANs on the trunk, issue the vlan trunk allowed command specifying only specific VLANs. Disabling spanning tree on the native VLAN of an IEEE 802. Understanding the Learn how to configure an ISL and 802. A port on a switch is either an access port or a trunk port. 1 Q trunks on the switch. Dec 11, 2024 · Configuring the Native VLAN for Untagged Traffic Configuring a Trunk Port Because trunk ports send and receive VTP advertisements, to use VTP you must ensure that at least one trunk port is configured on the device and that this trunk port is connected to the trunk port of a second device. 1Q trunk or disable spanning tree on every VLAN in the May 31, 2021 · To define the native VLAN for a trunk port, use the switchport trunk native vlan Interface Configuration mode command. 1Q VLANs Information About Access and Trunk Apr 25, 2018 · Syntax Switch (config-if)#switchport trunk native vlan <vlan #> Example In this example, the native VLAN for int fa0/2 is changed. Once you can get traffic to start jumping vlans If a Native VLAN is set to be a non-default # (lets say VLAN 150), and you want to only allow VLAN 10/15/20 over the trunk links, do you also need to include the NATIVE Vlan in your command "switchport trunk allowed vlan 10,15,20" or will it be implied that its the native VLAN so that traffic is inherently allowed? Do the following to set native VLAN characteristics on a trunk port for classifying the untagged traffic data packets. Feb 14, 2020 · In this activity, you will configure trunk links between the switches. Part 1, the previous lesson, covered how to configure access ports on Cisco switches. You can check the native VLAN also with the ‘ show interfaces trunk ’ command. The native VLAN by default is set to VLAN 1, however this can be changed using the following interface command. If the neighboring interface supports trunking and is configured to allow trunking, the link is a Layer 2 trunk or, if the interface is in Layer 3 mode, it becomes a Layer 2 trunk when you enter the switchport interface configuration command. The native VLAN should also be distinct from all user VLANs. If you do not intend to trunk across those links, use the switchport mode access interface configuration command to disable trunking. 1 q grade that was created for backward compatibility with the old device that does not endorse VLANs. By default, all switch ports in Layer 2 are configured to operate as access links. Example: Mar 31, 2025 · Configuring the Native VLAN for Untagged Traffic Configuring a Trunk Port Because trunk ports send and receive VTP advertisements, to use VTP you must ensure that at least one trunk port is configured on the device and that this trunk port is connected to the trunk port of a second device. Otherwise, the device cannot receive any VTP Description Configures VLAN IDs or VLAN names, and VLAN modes for a port access role. Access ports carry traffic from a specific VLAN assigned to the port. Otherwise, the device cannot receive any VTP switchport mode trunk switchport native vlan 111 switchport allowed vlan 112-113 switchport access vlan 110 I understand that the native vlan being 111 is where all untagged packets will go, but I was shocked that I can still have the command 'switchport access vlan 110' as part of the config. 1q tag under a normal 802. clear vtp counters Syntax Sep 27, 2007 · Bydefault your native vlan data will always pass through the trunk as untagg even if you see the output of "show interface switchport" command as "Administrative Native VLAN tagging:enabled". SW#conf t SW#int fa0/2 SW3(config-if)#switchport trunk native vlan 55 Here’s the trunking information for SW3. This lesson explains how to configure VLAN trunk link and native VLAN and Cisco IOS commands to configure VLAN trunk links and native VLAN One of the fundamental tools to achieve this is the use of trunk ports and the configuration of a native VLAN. Therefore, different VLAN numbers can be configured on both sides of a single trunk link leading to native VLAN mismatch. But what is the point when operating under switchport mode trunk? Doesn't switchport mode trunk filter all tagged frames such that the native VLAN (untagged PVID) would be meaningless? To prevent VLAN-Hopping and other security problems, can I just create a VLAN, let's call it VLAN 11 (name Native_VLAN) and specify VLAN 11 in switchport trunk native vlan 111 commands on all trunks? When native VLAN and management VLAN is configured with the same VLAN ID and a new VLAN is added as trunk port, both the new VLAN and native VLAN shifts between active and suspend state for a duration of 15 seconds. All ports in the same trunk must be in the same VDC, and trunk ports cannot carry VLANs from different VDCs. 10-15) To remove the access VLAN (which will require all traffic to be tagged) us the no form of the same command: no switchport access vlan Apr 25, 2018 · Syntax Switch (config-if)#switchport trunk allowed vlan <vlan #> Example In this example, allowed VLAN is set for int fa0/19 on SW3. Feb 17, 2022 · Hi All, I am having a problem discovering an AP in WLC everytime I configure its connection in the switch as trunk native vlan 306 which is I think is the standard. Feb 11, 2025 · This article describes VLAN and TRUNK MODE configuration concepts of VST. The native vlan is used to carry untagged traffic accross a trunk. set Max, Of course command "switchport access vlan" has no effect, because the port is not an access port, it is a trunk port. Dec 8, 2023 · Configuring the Native VLAN for Untagged Traffic Configuring a Trunk Port Because trunk ports send and receive VTP advertisements, to use VTP you must ensure that at least one trunk port is configured on the device and that this trunk port is connected to the trunk port of a second device. 1q trunking 1 Port Vlans allowed on trunk Fa0/1 1-1005 Port Vlans allowed and active in management Jun 18, 2009 · For example, to remove VLANs 5 through 10 and 12 from the trunk, issue the switchport trunk allowed vlan remove 5-10, 12 command. 1q vlan hopping. 1Q trunk link can be verified by issuing the show interfaces [name] switchport or the show interfaces trunk command, as illustrated in the following output: Apr 24, 2018 · switchport mode general switchport access vlan 220 switchport trunk native vlan 220 switchport trunk allowed vlan remove 1-4093 no lldp tlv-select dcbxp ets-config no lldp tlv-select dcbxp ets-recommend no lldp tlv-select dcbxp pfc no lldp tlv-select dcbxp application-priority exit * N2000 interface Gi1/0/40 switchport trunk native vlan 300 Apr 6, 2013 · Hi, I was curious about the switchport mode access command and its interoperability with the switchport voice vlan command. Dec 21, 2012 · If the port is in access mode and set to tag all traffic coming in as vlan 3, what in the world does the switchport trunk native vlan 2 command do? In what ways can this configuration be used for? Sep 24, 2015 · In Cisco devices you can do the command with no in front of it: no switchport access vlan 12. Otherwise, the device cannot receive any VTP Jul 9, 2023 · Step 4: Configure the native vlan: Without exiting from the interface configuration mode, enter the following command to configure the native vlan to vlan 1001 SW2(config-if)#switchport trunk native vlan 1001 Sep 26, 2025 · Use the switchport trunk allowed vlan command to specify which VLANs the port belongs to when its mode is configured as trunk. Dec 11, 2024 · The default mode for Layer 2 interfaces is switchport mode dynamic auto . Notice the ‘Port Vlans allowed on trunk for fa0/19’ section. You will assign ports to VLANs and verify end-to-end connectivity between hosts in the same VLAN. If tagging is required, use the command vlan trunk native tag. Jul 27, 2023 · The “switchport trunk native vlan” command is used to set the Native VLAN ID on a Cisco switch trunk port. Understanding Allowed VLANs Understanding Native 802. You want to seperate these from vlan 1 as well as the trunk links. May 22, 2017 · To change the native VLAN ID when the interface is in trunking mode, use the switchport trunk native vlan command. Mar 22, 2024 · This article discusses the Layer 2 switchport modes available and how to configure them on a Dell Networking N Series Switch. 2,10,500,4021), or a range of VLAN IDs (i. CLI Command The CLI command below is the equivalent to the payload example displayed in the pane on the right. All other vlans traversing the trunk are tagged with a vlan ID. Better way is to add VLAN with below command which will just add the new VLAN into trunk port and keep all the old one’s. To send data traffic untagged you must allow the native vlan through the trunk. If I configured a switchport with the switchport mode access commmand, will that make it impossible for the switchport to create a special case trunk with the IP phone? Even Jun 27, 2022 · Re-write all the VLANs in the command “switchport trunk allowed vlan vlan-id, vlan-id,vlan-id “ including the new VLAN and paste it on the interface. Command Mode Privileged User Related Commands switchport mode Example This example sets the native VLAN on GigabitEthernet 4/2 to 3. Putting the access VLAN on a trunk port does nothing unless the trunk goes down and the port reverts to an access port. switchport trunk allowed vlan A,B,C - Configure storm-control to generate traps in order to see if there is a lot of multicast or broadcast traffic. May 18, 2013 · Hello, I have an understanding that we can configure the tagging for native vlan to prevent from vlan hopping (double tagging) attack. To return the native VLAN ID to VLAN 1, use the no form of this command. Dec 23, 2019 · How to Configure VLAN Trunks To avoid trunking misconfigurations, configure interfaces connected to devices that do not support DTP to not forward DTP frames, that is, to turn off DTP. 802. 1q trunk link between two or more Cisco switches to pass all vlan traffic between Cisco switches. How to Use the Switchport Mode Access Command This command sets a port to Access mode for one VLAN. Jul 3, 2025 · Learn Cisco, configure trunk ports on switches including native VLAN and configure access port for Voice and Data VLANs. show vtp switchport mode private-vlan switchport priority extend switchport trunk vlan vlan dot1q tag native vtp (global configuration) vtp (interface configuration) vtp primary clear vtp counters To clear the VLAN Trunking Protocol (VTP) and pruning counters, use the clear vtp counters command in privileged EXEC mode. Trunk Configuration Commands Now that you have configured and verified VLANs, it is time to configure and verify VLAN trunks. on the trunk port by command "switchport trunk native vlan #". What i am saying is that the physical interfaces must have the same Sep 29, 2009 · I need confirmation of the "switchport access vlan" command below when the interface is configured as a trunk. This activity focuses on creating trunk Ensure that reserved VLANs are not used. 3 (3). To configure the trunk link, open console connection to Switch 1 and enter You just need to set the trunk encapsulation first, then go back to configuring the interface as a trunk. Assign the native VLAN ID with the command vlan trunk native. Example This example assigns native VLAN ID 20 to trunk interface 1/1/2. When VTP detects a new VLAN and the VLAN is not in the allowed list for a trunk port, the Native VLAN Tags #native #vlan #native-vlan When configuring trunk ports on a switch, the native VLAN is a configuration parameter on that port that tells the switch on which VLAN any untagged frames that arrive on that trunk port will be placed. Nov 7, 2023 · Create each VLAN using a unique ID number and name Configure access ports, indicating the VLAN to which each belongs Configure trunk ports, indicating allowable VLANs and the native VLAN Note: Naming the VLAN is optional but best practice. 1q trunk. switchport trunk native-vlan 10 Brocade: vlan 10 tag e1/1/x vlan 20 tag e1/1/x interface e1/1/x dual-mode 10 (this is the equivalent of native-vlan, deprecated in later releases of FastIron, you would simply untag your native vlan and tag everything else) You should be able to tag the vlans both from PFsense and the ICX, and it should work. Allowed VLANs can be specified on any trunk port with the switchport trunk allowed vlan command. Procedure Dec 8, 2023 · Configuring the Native VLAN for Untagged Traffic Configuring a Trunk Port Because trunk ports send and receive VTP advertisements, to use VTP you must ensure that at least one trunk port is configured on the device and that this trunk port is connected to the trunk port of a second device. See full list on networkacademy. Using the trunk allowed command lets you specify exactly which vlans are allowed over the trunk link, if they aren't in the list the vlan traffic will not go over the link Feb 28, 2025 · Use the switchport trunk native vlan Interface Configuration mode command to define the native VLAN for a trunk interface. Otherwise, the device cannot receive any VTP When native VLAN and management VLAN is configured with the same VLAN ID and a new VLAN is added as trunk port, both the new VLAN and native VLAN shifts between active and suspend state for a duration of 15 seconds. For trunk allowed VLAN names, you can delete the VLAN names individually or all names at once. This guide aims to equip you with the necessary steps to configure native VLANs effectively, enhancing network performance and security. Under this interface there is the command “switchport mode access” that is why you have “static access” “Native” is an indication that your untagged packets are using the switch default of vlan 1. Can someone explain this command and what it does? Thanks, Matt Dec 7, 2021 · show vtp switchport mode private-vlan switchport priority extend switchport trunk vlan vlan dot1q tag native vtp (global configuration) vtp (interface configuration) vtp primary clear vtp counters To clear the VLAN Trunking Protocol (VTP) and pruning counters, use the clear vtp counters command in privileged EXEC mode. Apr 25, 2018 · Syntax Switch (config-if)#switchport trunk native vlan <vlan #> Example In this example, the native VLAN for int fa0/2 is changed. Jul 4, 2007 · 07-04-2007 07:18 PM Hi Jack The native vlan is the vlan that is not tagged with a vlan ID on an 802. Following example shows how to create and configure trunk link to carry multiple VLAN traffic and how to configure the native VLAN for a trunk link. Only allowing through VLAN traffic on physical switch ports connecting to ESX reduces TCP/IP overhead. Ensure that the native VLAN for an 802. Instructions Part 1: Verify VLAN configuration. DTP offers four switch port modes: access, trunk, dynamic auto, and dynamic desirable. Jan 12, 2021 · # X is the VLAN ID To specify which tagged VLANs to accept: switchport trunk allowed vlan XYZ # XYZ can be a single VLAN ID, a list of VLAN IDs (i. It only works on switchport access vlan 304. Understanding the Master configuring VLANs on Cisco switches. Dec 8, 2023 · The default mode for Layer 2 interfaces is switchport mode dynamic auto . A VLAN trunk is a Layer 2 link between two switches that carries traffic for all VLANs (unless the allowed VLAN list is restricted manually or dynamically). If a PC is connected to this interface, and it isn't trunking, traffic will be sent on VLAN 53 (Native) right? so, therefore, the "switchport access vlan 600" isn't being used? or does Apr 1, 2009 · I am trying to replace an older switch with a new switch but whoever configured the old switch configured the interfaces with this: interface FastEthernet0/12 description Center Lab switchport access vlan 214 switchport trunk encapsulation dot1q switchport trunk native vlan 112 switchport trunk all Dec 19, 2019 · Cisco recommends not using VLAN 1, restricting VLAN 1 from trunk links (switchport trunk allowed command), and not using a native VLAN on the trunks, meaning that all the VLANs on a trunk would be tagged, and there would be no VLAN 1 frames. Jun 7, 2024 · This document describes the difference of IEEE 802. To add a VLAN to the trunk, issue the switchport trunk allowed vlan add vlan-list command. A trunk port can become a member of a VLAN if the VLAN is enabled, if VTP knows of the VLAN, and if the VLAN is in the allowed list for the port. you can check that if you look in output of "shor run all" command for the appropriate port. Jun 9, 2022 · You would usually use a high number for the VLAN and one which is unused by hosts. The switchport trunk native vlan command specifies the native (untagged) VLAN for a Layer 2 interface operating in trunk mode on a Cisco IOS device. Therefore, it carries traffic for all VLANs. In this lesson we learn how to configure trunk ports on Cisco switches and how to configure router on a stick (ROAS) for inter-VLAN routing. Below is what that configuration may Mar 31, 2025 · If the native VLAN tagging global command is enabled on the switch, you should disable the tagging of native VLAN packets on selective QinQ enabled ports using the command no switchport trunk native vlan tag command. Jun 5, 2015 · I am trying to better understand how an interface with the command "switchport trunk native vlan 600" handles sending or receiving frames containing a vlan 600 tagged frame. Make sure the native VLAN for an IEEE 802. Apr 11, 2025 · A Native VLAN is the VLAN that carries untagged traffic on a trunk port. VLANs can be as multitudinous as there are. 1q originally included the native vlan functionality to make transitioning a port to trunk state easier, but it left open the possibility that a maliciously crafted packet (sticking a second 802. Mar 31, 2025 · Configuring the Native VLAN for Untagged Traffic Configuring a Trunk Port Because trunk ports send and receive VTP advertisements, to use VTP you must ensure that at least one trunk port is configured on the device and that this trunk port is connected to the trunk port of a second device. By default, the native vlan is configured to vlan 1, but in most cases, you need to manually configure this to an unused vlan. How can i check that This tutorial explains how the native VLAN works and how to change it on Cisco Catalyst Switches. This article explains the native VLAN, which is by default, switch ports will pass traffic for one virtual LAN, or VLAN, and one VLAN only. This tutorial explains how the native VLAN works and how to change it on Cisco Catalyst Switches. The native vlan carries other traffic such as DTP updates. When I run switchport interfaces trunk, it shows that vlan 306 is allowed on that particu Feb 15, 2020 · This article provides instructions on how to configure an interface VLAN as an access or trunk port on your switch through the CLI. Master configuring VLANs on Cisco switches. Note: VMware recommends utilizing VLAN technology to establish dedicated subnets for ESX/ESXi management, VMotion, and iSCSI network traffic. Non-existed VLANs can be configured. The Trunk Native VLAN allows untagged frames arriving on a trunk port to be placed into a specific VLAN: the native VLAN. "switchport trunk allowed vlan #" is a replace statement, that replaces the current allowed vlans with the ones in the statement The no switchport trunk native vlan and default switchport trunk native vlan commands restore vlan 1 as the trunk mode native VLAN to the configuration mode interface by removing the corresponding switchport trunk native vlan command from running-config. 1Q tagging. However, Glynn's question may also mean: Is it possible to have switchport trunk native vlan configured on an access port? The command switchport trunk native vlan <vlan-id> is the correct command to configure the native VLAN on a trunk link in Cisco IOS XE and NX-OS switches. The trunk port carries traffic for two or more VLANs. Why Native VLAN? The Native VLAN is one conception defined in the 802. Learn to verify with show commands. Feb 8, 2022 · To configure the port as a Layer 2 port using the CLI, use the switchport command. The no form of this command removes a native VLAN from a trunk interface and assigns VLAN ID 1 as its native VLAN. 1Q Trunking Ports Configuring the Allowed VLANs for Trunking Ports Configuring Native 802. Otherwise you change it with "switchport trunk native vlan " command. This VLAN sends and receives untagged traffic on the 802. Allow traffic tagged with the native VLAN ID to be transported by the trunk using the command vlan trunk allowed. Jan 17, 2025 · Switchport Configuration Commands and Their Functions Network admins use switchport modes to control packet flow. This article explains how to configure Native VLAN (untagged or access VLAN) on a Trunk port in OS10 Switches. Figure 1. These features are pivotal when it comes to enabling communication between multiple switches and ensuring traffic for various VLANs can coexist over a single physical connection. To revert to its default setting, use the no form of this command. e. Learn how to configure, test, and verify VLANs on Cisco switches. We recommend that you leave spanning tree enabled on the native VLAN of an IEEE 802. The point is that what happened to untagged ones like traffic from low end devices such as soho switches which are connected at the other end and they don't underst Command Mode Privileged User Related Commands switchport mode Example This example sets the native VLAN on GigabitEthernet 4/2 to 3. You will configure trunk links between the switches, and you will configure VLAN 999 as the native VLAN. You can configure either VLAN IDs or VLAN names, or a combination of both for a role. Otherwise, the device cannot receive any VTP Network OS Command Reference 1291 53-1003115-01 switchport trunk native-vlan 2 switchport trunk native-vlan Sets native VLAN characteristics as an 802. This will make a new vlan# as native & allow all pkts from this vlan to pass thru trunk untagged. Learn to configure Access and Trunk ports, and Native VLANs and Allowed VLAN Lists. Procedure My understanding is that for multiple vlan, i need to set the port's switchport to trunk. Otherwise, the device cannot receive any VTP Jan 10, 2025 · A trunk port is a switch interface configured to carry traffic for multiple VLANs by using VLAN tags. SW0#show interfaces trunk Port Mode Encapsulation Status Native vlan Fa0/1 on 802. nfedn luxtidaqo kqhru wapqs yktjoehzg tpqt cwwt swxnlo bkwgbuf pen ylvd hple xrda ewfycm pvx