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Cisco 3850 inter vlan routing

By | 03.10.2020

I have recently fell in love with the Cisco SG line of switches. They are high powered and easy to administer. Before you start it is a good idea to sit down with a pen and paper can sketch out your deployment so when you start, you have a vision of how you want it to operate.

Pretty obvious first step. Install your switch and connect it to your network. In this guide I am using an SGP. I used a network scanner to find out what IP mine had been assigned but you could also look through your DHCP scope or setup a reservation in advance. After you identify what IP your switch has been assigned, navigate to that IP in a web browser. I have had issues with the interface with Internet Explorer so you might want to try Chrome or Firefox if you run into problems.

It may have you change the password right away, don't bother getting to crazy with any of that yet because in the next step we are going to switch it over to layer 3 mode which will wipe all of your settings. The switch out of the box will be operating in layer 2 mode.

This won't work for what we need it to do. Your switch will reboot and all of the settings will be cleared. When it comes back up, it will be operating as a layer 3 switch. When the switch comes back up, if you didn't set a reservation in DHCP, it may have a new IP so you might have to search for it again. Find the IP of the switch and login, at this point you can set a new password if you choose. After you have logged in, you will want to statically assign an IP to your switch.

Check the box next to the VLAN 1 interface and delete it. I usually like to have my network equipment at the end of my IP block. Make sure that whatever IP you assign isn't currently being used by another device! If the IP you assigned to your switch is different than the one it initially had, you will need to navigate to the new IP to continue working on it. Now that we have the initial administrative functions out of the way, you will need to create a VLAN. Click on Add. Click Add For the subnet mask I used a prefix length of 24 but if you want more IPs then make the adjustment accordingly.

The switch will automatically create the routing for your VLAN'd devices when they are plugged into the switch. It won't create the route until it has a device plugged into it that is in that VLAN so keep that in the back of your mind. So at this point we need to create a new static route on the firewall so the new VLAN can access the Internet.

You will also want to create an address object for your switch because we will need it for the next step. You will need to create a new static route for each new VLAN you create. Now that everything is set, in order for your devices to communicate across VLANs, they need to use your Cisco switch as the default gateway.Current configuration : bytes!

Go to Solution. Unfortunately the most of the switches except or others dont support NAT to translate the internal traffic to public IP address. You need a firewall or router to achieve this task. View solution in original post. Unfortunately the platform does not support NAT. The ios-xe is a modular ios. This means that inside the ios-XE we have a regular ios. This regular ios has the commands and that is the problem. There is already an internal bug to remove this CLI commands from the ios release.

I heard some member saying that if following three NAT commands are accepted then this L3 switch can connect to the internet; which are accepted in this switch. Can you please be more specific if possible? This model does not support NAT but the switches like and does. Please check this link:. I have several vlans and ip routing is enabled and intervlan is working fine. All the hosts in the vlan use private address ranged I have a interface on my firewall with an IP What do I need to do to access Internet from all the hosts in my vlan.

Please help me I am stuck in this for quite a long time now. Buy or Renew. Find A Community. We're here for you! Turn on suggestions. Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.

Showing results for. Search instead for. Did you mean:.The document provides a sample configuration for interVLAN routing with a Catalyst series switch that runs enhanced multilayer image EMI software in a typical network scenario. The document uses a Catalyst series switch and a Catalyst G switch as Layer 2 L2 closet switches that connect to the Catalyst The Catalyst configuration also has a default route for all traffic that goes to the Internet when the next hop points to a Cisco VXR router.

You can substitute a firewall or other routers for the Cisco VXR router. The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared default configuration. If your network is live, make sure that you understand the potential impact of any command. Refer to Cisco Technical Tips Conventions for more information on document conventions.

Configuring InterVLAN Routing with Catalyst 3750/3560/3550 Series Switches

Devices within a VLAN can communicate with each other without the need for routing. Devices in separate VLANs require a routing device to communicate with one another.

L2-only switches require an L3 routing device. The device is either external to the switch or in another module on the same chassis. A new breed of switches incorporate routing capability within the switch.

An example is the A typical network design segments the network based on the group or function to which the device belongs. For example, the engineering VLAN only has devices that relate to the engineering department, and the finance VLAN only has devices that relate to finance.

If you enable routing, the devices in each VLAN can talk to one another without the need for all the devices to be in the same broadcast domain. Such a VLAN design also has an additional benefit. The design allows the administrator to restrict communication between VLANs with use of access lists. You can forward these non-IP packets with fallback bridging.

In order to use this feature, you must have the IP services image, formerly known as the enhanced multilayer image EMIinstalled on your switch. In this section, you are presented with the information to configure the features described in this document. In this diagram, a small sample network with the Catalyst provides interVLAN routing between the various segments. By default, the Catalyst switch acts as an L2 device with disablement of IP routing.

The default gateway configuration on each server and host device must be the VLAN interface IP address that corresponds on the For example, for servers, the default gateway is This document provides a sample configuration for inter-VLAN routing using two Catalyst s series switches stacked together running EMI software in a typical network scenario. The document uses a Catalyst series switch and a Catalyst G switch as Layer 2 L2 closet switches connecting to the stack of Catalyst s.

The stack of Catalyst s is also configured for a default route for all traffic going to the Internet with the next hop pointing to a Cisco VXR router, which can be substituted by a firewall or other routers. Configuring inter-VLAN routing on a single is the same as configuring this feature on a Catalyst series switch.

For more information on document conventions, see the Cisco Technical Tips Conventions. The information presented in this document was created from devices in a specific lab environment. All of the devices used in this document started with a cleared default configuration. If you are working in a live network, ensure that you understand the potential impact of any command before using it.

Devices within a VLAN can communicate with one another without requiring routing. On the contrary, devices in separate VLANs require a routing device to communicate with one another.

L2 only switches require a L3 routing device either external to the switch or in another module on the same chassis. A new breed of switches, however, for example, and incorporate routing capability within the switch. A typical network design segments the network based on the group or function the device belongs to.

For example, the engineering department VLAN would only have devices associated with the engineering department, while the finance VLAN would only have finance related devices. If routing is enabled, the devices in each VLAN can talk to one another without all the devices being in the same broadcast domain.

On a stack of Catalyst switches, the software running on the master determines the capabilities of the whole stack. However, it is advisable to have the same software running on the different stack members.

If the stack master fails, you would lose the extended routing capabilities if the other members run an SMI image as opposed to the EMI image of the former master. A stack of Catalyst switches appears to the network as a single router, independent to which of the stack switches the routing peer is connected. A router will create a single adjacency with a stack of routers.

cisco 3850 inter vlan routing

When the master fails, the stack members will apart from a momentarily interruption continue to forward the packets in hardware while no protocols are active. After a new master has been selected following a master failure, the newly elected master will start sending gratuitous ARPs with its own MAC address in order to update the devices in the network with the new MAC address that will be used to rewrite the routed packets.

For more information regarding switch stack behavior and configuration, refer to the Managing Switch Stacks documentation. In this section, you are presented with the information to configure the features described in this document. The above diagram shows a small sample network with the stack of Catalyst s providing inter-VLAN routing between the various segments.

The default gateway configured on each server and host device should be the corresponding VLAN interface IP address on the stack of s. For example, for servers, the default gateway is The Catalyst is trunked to the top Catalyst switch stack master and the Catalyst G is trunked to the bottom Catalyst switch stack member.

The default route for the stack is pointing to the Cisco VXR router.Trunking is a way to carry traffic from several VLANs over a point-to-point link between the two devices. Two ways in which Ethernet trunking can be implemented are:. To create the examples in this document, we used the following switches in a lab environment with cleared configurations:. The configurations in this document were implemented in an isolated lab environment.

Ensure that you understand the potential impact of any configuration or command on your network before using it. The configurations on all devices were cleared with the write erase command to ensure that they have a default configuration. For more information on document conventions, refer to the Cisco Technical Tips Conventions.

Catalyst and series switches only support For The native VLAN is used for untagged traffic when the port is in While configuring It is a common mistake not to match the native VLANs while configuring Router models with certain network modules may have different minimum Cisco IOS versions.

For a complete list of minimum supported software for any router family, use the Software Advisor registered customers only. To determine the best maintenance release for your Cisco product, search for bugs listed by product component in the Bug Toolkit registered customers only. For a complete list of other feature sets supported in different Cisco IOS versions and on different platforms, use the Download Software area.

In this section, you are presented with the information to configure the features described in this document. Comments between the commands are added in blue italics to explain certain commands and steps. If you are using an earlier version of Cisco IOS, refer to the For workstation1, the default gateway should be For details on how to set the default gateways on the workstations, refer to their respective sections in this document.

The bug fix was integrated in the following code versions: You can check the status and a brief description of the bug by using the Bug Toolkit registered customers only and entering the bug ID CSCds For details on how to set the default gateways on the workstations, refer to thei respective sections in this document. Certain show commands are supported by the Output Interpreter Tool registered customers onlywhich allows you to view an analysis of show command output.

This command is used to check the administrative and operational status of the port. It is also used to make sure that the native VLAN matches on both sides of the trunk. This command is used to verify that the interfaces ports belong to the correct VLAN. The rest are members of VLAN1.

cisco 3850 inter vlan routing

In our example, we have used transparent mode. The correct VTP mode depends on the topology of your network.

cisco 3850 inter vlan routing

Contents Introduction. ISL is not supported. VLAN1 already exists by default.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

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New to Cisco stuff so bear with me only a little L2 Procurve experience. I am not in charge of the C, but it looks like the VLAN's appear to be sending and receiving correctly, based on some testing from a hypervisor server hanging off the C From the C is another trunk to yet another C, with the correct trunk settings for the VLAN's I want to haul from the development network to the second switch.

I can't do basic pings on the dev VLAN's from the second switch.

Configuring Inter-VLAN Routing with Catalyst 3750 Series Switches

Some people involved with setting up the C said I would have to add an IP in the subnet of the VLAN at the Cisco router to make it bridge the VLAN's from the first to the second switch, but I don't want routing and setting a next hop seems bizarre.

Since the Cisco router is currently a core router, I can't ask to make the whole thing behave like a dumb switch. Is there a proper way to transparently bridge the VLAN's between ports on the router without routing or needing an IP at the router, while preserving existing routing, so I can send traffic from the second C to the Aruba switch?

The Cat and the Cats are definitely capable of what you intend to do, which is what VLANs, trunking and switching are all about. But - there may be operational guidelines preventing it. To get traffic from one network VLAN to another requires a router.

Even if you bridge the VLANs at layer-2, the devices on the different networks will be unable to communicate. A host will look at the destination address, and it can tell that it is on a different network. If it is, then it will send the frame to its configured gateway router. A router is a host on the LAN that knows how to forward packets to a different network. The purpose of VLANs is to break up the network into separate layer-2 domains, and it requires a router at layer-3 to forward packets between the separate networks.

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Active 1 year, 5 months ago. Viewed times. Asteroza Asteroza 31 1 1 bronze badge. Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can provide and accept your own answer. Active Oldest Votes. That should be possible - provided that Marc 'netztier' Luethi Marc 'netztier' Luethi 6, 1 1 gold badge 6 6 silver badges 26 26 bronze badges.

I agree. It sounds like the 2nd switch hanging off the is on a different vlan or they have restricted which vlans can pass through the trunk. It's very common to see vlans restricted on the core switch i.

As far as I am aware, the trunks connecting the three Cisco devices should have also had the VLAN's tagged and allowed. I feel like there's some sort of additional prep work at the C to make the jump to the second C that I don't clearly understand. I am hauling multiple VLAN's, but the subnets they contain don't interact with each other and never mix. Sorry if that wasn't clear enough in the description.I am trying to establish inter vlan connectivity between two switches.

I setup a test environment in my private lab as follows. PC's are pinging each other in the same switch as I enabled "ip routing" command on the switch. I also tried enabling trunk mode on both the switches but no success.

Could anybody help me in this. Go to Solution. One way, would be to define a routed port on each and configure it as a p2p link between the two switches.

Configuring Inter-VLAN Routing with Catalyst 3750 Series Switches

Then you could static route or run a routing protocol between them. View solution in original post. Create another vlan which is available on both switches and configure static routing or enable dynamic routing e. Switch 1 VLAN Switch 2 VLAN This example uses static routing but you could do the same by enabling dynamic routing between the switches. Actually I tried RIP also but it didn't work out. You can check from the screenshot of Switch 2 IP Route.

I did same in Switch 1 also. Please refer to the screen shots where I am making mistake in routing. Yes it is up. I ran no shut after assigning IP to vlan I did sh ip route and still it showing C paths. Is there a need to assign a port to vlan and make that port trunk to each other with dot1q encapsulation? There is no reason to make the ports between the 2 switches trunk, just stick it in vlanwhat subnet are you using for vlanand what IP in that subnet did you put on each switch and can you ping from one to the other?

I created vlan and assigned IP Same in switch 2 vlan with IP Priority goes to the primary vlan's of the switches. Please bare with me I am new to Cisco. Could you please tell. Hi tried your configuration in Packet tracer with Switches by creatingvlan on switch 1 andon switch 2 with some ports assigned to both the vlans. And enabled Ip Routing. One PC is connected to each vlan in both the switches. Buy or Renew. Find A Community. We're here for you! Turn on suggestions.

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Cisco Inter VLAN Routing Configuration Examples

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