vlan – vswitchzero

Welcome to part two of a series on configuring the MikroTik CRS309-1G-8S+IN for use in a VMware home lab. In part one, I discussed RouterOS and how to get VLAN trunking configured for all ports from the CLI. Today I’ll be configuring inter-VLAN routing. Keep in mind that I’m using the CRS309, but this should be applicable to the popular CRS317 and other CRS3xx switches running RouterOS as well.

As I mentioned in my unboxing and overview post, the CRS309 is a fully featured L3 switch. It uses the Marvell Prestera DX switching chip with a forwarding ASIC for line-rate L2 performance at very low power consumption levels. This is great for a home lab, because your non-routed vSAN, iSCSI and vMotion kernel traffic can take advantage of full 10Gbps line rate throughput. To use the L3 features, however, the CRS3xx switches rely on the integrated 32-bit ARM CPU cores in the Prestera DX. This means that things like inter-VLAN routing, firewalling and other L3/L4 features are done in software. MikroTik rates the switch for around 2.5Gbps for anything that will need to be processed by the CPU cores. None the less, this is still plenty of routing throughput for a home lab and I’m really happy that they include a huge number of these features even if they are somewhat performance limited.

VLAN Interface Creation

In the part one I relied on the CLI to get started. Now that we have a management IP configured, we can continue in the UI. To get inter-VLAN routing working on the CRS3xx series switches, there are two steps – first, we’ll need to create VLAN interfaces with the correct VLAN ID specified. Second, we need to assign an IP address to these interfaces.
If you recall in part one, I created a VLAN interface in VLAN 1 to get management connectivity to the switch again. That interface is visible in the UI from the Interfaces/VLAN tab:

crs309-intervlan-1

As a next step, I’ll create VLAN interfaces for the other five VLANs (11,76,98,2005 and 3156). Click the ‘Add New’ button to create a new one. I’ll start with VLAN 11 as an example.

crs309-intervlan-2

In my case there were only three options I needed to change – name, VLAN ID and Interface. I like to give my VLAN interfaces the names INT_VLANX for consistency. Be sure to assign the VLAN interface to the bridge that you created previously so that it is accessible from all ports on the switch. I repeated this for all of my VLANs.

Continue reading “MikroTik CRS309 Configuration – Part 2”

This will be the first of several posts on configuring the new MikroTik CRS309-1G-8S+IN for use in a VMware home lab. Today’s first post will introduce MikroTik’s RouterOS and will focus on VLAN trunking. Please note that although this was written for the CRS309, this should be applicable to all CRS3xx series switches, including the popular CRS317.

RouterOS vs SwOS

MikroTik’s RouterOS firmware that comes pre-loaded on the switch is very feature rich with loads of L3 functionality. It has everything from BGP/OSPF, to firewalling, NAT, DHCP services – you name it. It’s a multi-purpose firmware that was originally created for MikroTik’s routers. Today, it works with many of their other products, including switches, and wireless devices. Because of this, it feels more like router firmware adapted for use with switches as opposed to something designed especially for them. Configuring RouterOS on the CRS309/CRS317 can be challenging and there is a learning curve to overcome – even for those with a lot of networking experience. Things get easier when you learn the terminology and understand what does and does not apply to a switch within RouterOS.

The CRS309 also includes ‘SwOS’ – a straight-forward L2 firmware that is designed especially for their switches. I found SwOS’s UI to be very intuitive and a lot more like what I’d expect to see on a switch. If you are not looking to use any of the advanced L3 features that RouterOS offers, I’d highly recommend using SwOS instead. There is no need to flash back and forth from RouterOS to SwOS and vice-versa. Both firmware packages coexist in the flash memory and you can easily switch back and forth as required.

Although SwOS could suffice for my needs in the home lab, I’m not one to shy away from a challenge and really want to be able to take advantage of some of the L3 features. If I could get them to work, I could potentially retire one or two virtual machines that I currently use for routing and firewalling.

802.1q VLAN Trunking

One of the first things I tried to do with the CRS309 was get a bunch of VLANs created and all the interfaces configured as 802.1q VLAN trunk ports. This is probably the most common VMware home lab requirement with 10Gbps networking. Each host will have a limited number of interfaces, so VLAN trunks are critical to separate out the various services.

When you get into the RouterOS WebFig interface, you’ll find several places where VLANs can be configured. My first attempt was under ‘Switch’ and ‘VLANs’ – sounds logical enough:

crs309-vlans1

But clearly this doesn’t work. There is also a section for VLANs under ‘Interfaces’, but this is for VLAN interface creation, which I’ll get into later. One of the first things to keep in mind with RouterOS is that a lot of the configuration relating to the switch – including VLAN configuration – is done in the ‘Bridge’ section – not the Switch section.

From the CRS3xx series manual:

“Since RouterOS v6.41 bridges provide VLAN aware Layer2 forwarding and VLAN tag modifications within the bridge. This set of features makes bridge operation more like a traditional Ethernet switch and allows to overcome Spanning Tree compatibility issues compared to configuration when tunnel-like VLAN interfaces are bridged..”

Another important thing to remember is that any VLAN related configuration you do in the bridge does not come into effect until an option called vlan-filtering is set to ‘yes’ for the bridge itself.

Continue reading “MikroTik CRS309 Configuration – Part 1”