WLC

WN Podcast 021 – Cisco Catalyst 9800 – Built & Basics

Welcome to our new WiFi Ninjas Podcast episode!

Today, we kick of the Cisco Catalyst 9800 Podcast series, where we will cover some nitty & gritty stuff and share our real world deployment tips and experiences about those new, hot WLCs!

Let’s start with basics πŸ™‚

  • What is C9800?
  • 9800-80 – 2RU Appliance
    • 80Gbps
    • 6000 APs
    • 64,000 Clients
    • 100Gbps Uplink Module Option!
  • 9800-40 – 1RU Appliance
    • 40Gbps
    • 2000 APs
    • 32,000 Clients
  • 9800-CL – Public/Private Cloud Virtual Controller
    • VMWare/KVM/AWS/GCP
    • 2Gbps of centrally-switched traffic
    • 6,000 APs
    • 64,000 Clients
    • Supported features that were not supported on the AireOS vWLC
      • SSO High Availability
      • Local or Flex Mode APs
      • Guest Anchoring
  • 9800-SW – Embedded 9300/9500 Switch Controller
    • 200 APs
    • 4,000 Clients
    • Indirect AP Support (APs can be connected to downstream switches)
  • 9800-L
    • 250 Aps
    • 5000 clients
    • Max throughput 5Gbps
    • Fixed uplinks 2 x 10gbps
  • Features
  • Built
    • VMware
      • Networking
        • 3 interfaces
        • HA considerations
        • Trunk
          • Accept Promiscuous Mode!
        • Central vs Flex
        • OOB
          • Not used
      • Kill the autoinstall, CLI (at least for us) is quicker
      • VLAN and SVI for mgmt
      • Set country code
      • Specify interface (mgmt SVI) to be used for wireless mgmt / AP join
      • Create a cert, validate its creation with sh wireless management trustpoint
      • Configure SSH
    • Physical
  • Challenges
    • Internal DHCP
      • ‘Reserved Only’ turned on by default
      • Configure DHCP Pool, starting IP, ending IP, lease time, gate, DNS, domain
      • Set DHCP Server IP address to be C9800 mgmt.
    • Prime bug
    • Compatibility with other Cisco infra
    • AAA attribute
  • Guest Flow
    • MAB CWA
    • Redirection ACL is not applied anywhere, it’s just referred to by ISE AuthZ Profile
    • Use WLAN guest ACL or have it referenced back by RADIUS

With tons of love x,

WiFi Ninjas

WN Blog 010 – Cisco Catalyst 9800 – Configuration Guide (Basics & Central Switching)

Finding C9800 stuff hot and interesting? You’re not alone out there! πŸ™‚

After initial C9800 configuration (see this blog) and registering your first AP (our AireOS AP Join Blog is still applicable here) you’re pretty much ready to go! There are just some pre-reqs to consider before we can associate with our first C9800 BSSID.

Pre-reqs

  • C9800 is built, GUI and CLI access is working
  • AP is registered
  • AP mgmt. VLAN (VLAN 10 in this example) is operational, AP has connectivity with to at least the vWLC
  • VM mgmt. VLAN (VLAN 11 in this example) is operational, C9800 can communicate with the network
  • WiFi Users VLAN (VLAN 20 in this example) is operational and, since it’s central switching we talk about here, VLAN 20 is allowed on C9800-CL management trunk (Gi2 in this example), on Port Group on the vSwitch C9800 Gi2 is mapped to and on ESXi management trunk to the switch; VLAN 20 must be allowed across entire path from the C9800 to its gateway

Note: since we’re talking central switching mode here, authenticated WiFi users’ traffic will be dropped into WiFi users VLAN at the vWLC level!

Lab Environment

To get better picture, see my lab environment below:

Lab Environment

New C9800 Architecture

Even though C9800 offers pretty much features parity with our beloved AireOS WLC, it is slightly different. If you spent some quality time with Cisco DNA Center you will feel comfortable with the new GUI and structure. If not (like me), be prepared to change some old habits and approach C9800 with an open mind πŸ™‚

C9800 is designed to fit perfectly into Cisco SDA world and integration with DNAC and use of SGTs. But don’t worry if you don’t have few DNAC boxes worth Β£70k each and a fabric underlay lying around. C9800 can still work in a traditional way. The only real difference is where we configure the same stuff as we did in AireOS (using Profiles) and how we stich it together (using Tags).

Look at the visual representation of major blocks building a basic WiFi setup.

Wireless Setup Flow Overview

You can create multiple WLAN Profiles (SSIDs) and Policy Profiles and correlate both using a single Policy Tag. You then choose your AP Join Profile and Flex Profile (if in use) and correlate both using Site Tag. Your 2.4 and 5GHz RF profiles are stitched together using RF Tag. You now have all the config needed for the AP and SSID to operate described with just 3 tags, that are finally assigned to the AP of your choice. Takes some time getting used to, but it’s really not too bad.

Let’s dive straight in. Once we start looking at the real config it shouldn’t feel too overwhelming.

Note: only the WLAN Policy is mandatory but it is best practice to use all 3 policies and understand impact they all have on our wireless network.

Configuration

In this example we’ll configure simple WPA2-PSK WLAN and cover more interesting stuff like popular enterprise security approaches using EAP (PEAP, EAP-TLS, BYOD) in future blogs! Guest flow (CWA with ISE) already has its blog and you can find it here: https://wifininjas.net/index.php/2019/08/13/wn-blog-009-c9800-wlc-guest-mab-cwa-ise/ πŸ™‚

Below steps show how to configure your first centrally switched WLAN. It’s PSK-based, but you can easily translate it to any other auth method. Have fun πŸ™‚

1. Configure WLAN Profile

This is a pretty standard WLAN configuration that we’re all familiar with. Quite a few boxes to tick, tons of possibilities, standard Cisco overcomplication that feels like 1:1 port from the AireOS. Simplifying opportunity missed. But let’s not digress!

Go to Configuration > Tags & Profiles > WLANs or (I like to do that), Advanced Wireless Setup (top-right corner), where you can switch between all main solution building blocks from one list.

Advanced Wireless Setup

Amazing, isn’t it?

In General tab, configure Profile Name (must be unique) and SSID name (can have more than one on the same WLC) along with WLAN ID (ID <=16 = included in default Policy Profile, ID > 16 = won’t be included in default Policy Profile), Radio Policy (2.4GHz, 5GHz, or both). As L2 security in Security tab, use WPA + WPA2 with AES encryption and PSK key mgmt and specify ASCII PSK Key. FT should be disabled here due to Krack vulnerability. Leave all other security details on their default values. Advanced tab settings can also be left on default but please be mindful of the impact some settings on the performance and compatibility of your SSID. This is a topic for another discussion, but in essence I’d say that:

  • Aironet IE enables SSID name inclusion in beacons among many other things, which is helpful AF but can affect clients compatibility with this SSID
  • P2P Blocking is normally enabled on Guest SSIDs (blocks WiFi clients from attacking each other)
  • 802.11v can seriously affect (positively or negatively) your roaming behaviour – test with your clients
  • 802.11k is generally a good feature to use as it should reduce time your clients spend scanning off channel for alternative APs while roaming
  • Band select can be useful in some scenarios, but steer away when used with voice as it will make roaming slower
WLAN Profile General tab
WLAN Profile Security tab

2. Create a VLAN

Since we’re dealing with central switching, we might think that we would need a dedicated SVI on the C9800 sitting in the VLAN into which we would like to drop authenticated users’ traffic in the same fasion as we did in AireOS. We could do it and it would work, but it’s not necessary here. All we need is to create VLANs (as opposed to SVIs) to get centrally switched WLANs to work.

Add VLAN in CLI ((config)#vlan [VLAN ID]; (config-vlan)#name [VLAN name]) or GUI in Configuration > Layer2 > VLAN > Add

In this example I’m using VLAN 20 for wireless users. L3 sits on my core switch. VLAN 20 is allowed on vSwitch and ESXi trunk. Refer to the lab network diagram for more clarity – one pic speaks thousand words.

Add VLAN for wireless users

3. Configure Policy Profile

This is where we can configure TrustSec, decide if we want to use Central Switching, Authentication, DHCP or Association, map WLAN to a VLAN, apply an ACL to an SSID, turn on RADIUS Profiling, specify QoS, AVC, CAC, Anchors, AAA Policy (attributes returned to the NAC), basic WLAN timers and many more. Sounds easy? I know, I too feel it’s slightly on the overcomplicated side πŸ™‚

General Tab:

Policy Profile – General Tab

Minimum config required:

  • Specify Name
  • Set Status to ENABLED
  • Enable Central Switching and Central DHCP

If you want to know more:

  • WLAN Switching Policy can move certain roles (switching, auth, DHCP, association) between AP and WLC. Central everything is the default. Note that “Central DHCP” must be used in Central Switching mode. If you disable it, clients won’t get an IP at all. Authentication and Association roles can be moved between WLC and AP and either would work just fine.
  • Passive Client (in short) allow comms from wired devices to wireless devices with static IP address by enabling WLC to pass ARP requests to them. Normally WLC proxies that responses but since there is no DHCP used, WLC wouldn’t know about those devices.

Access Policies Tab:

Policy Profile – Access Policies Tab

Minimum config required:

  • Specify VLAN/VLAN Group assignment (use just a VLAN number or use VLAN name set in step 2.)

If you want to know more:

  • VLAN/VLAN Group is where we specify the VLAN we want to drop wireless users into! This is extremely important to understand, since we don’t assign WLANs to dynamic interfaces (central) nor we have VLAN to WLAN mapping (flex) anymore. I have assigned ‘LAB-WIRELESS-USERS’ VLAN 20, that I created in step 2.
  • WLAN ACL can be applied to do basic firewalling on the AP or WLC level (depending if using central switching or Flex) before the traffic even hits the firewall.

Let’s leave the rest on default for now. We’ll cover it in more details in future blogs.

4. Configure Policy Tag

Policy tag just stitches WLAN Profile and Policy Profile together, nothing else πŸ™‚

We could mix and match different WLAN and Policy Profiles while creating different tags. Example:

  • PSK WLAN with Policy Profile on VLAN 20
  • EAP WLAN with Policy Profile on VLAN 20
  • MAB WLAN with Policy Profile on VLAN 666

You get the drill.

Policy Tag

Minimum config required:

  • Create a new Policy Tag and select WLAN and Policy Profiles created in previous steps

5. Configure AP Join Profile

Here we’ll configure basic parametres used by APs after they join a controller.

AP Join Profile – General tab

Minimum config required:

  • Specify AP Join Profile Name

If you want to know more (I’ll only mention stuff I think is useful and filter out the noise):

  • If setting up a quick SSID is all we need, we can just create AP Join Profile, and specify its name in General tab. All other settings within the AP Join Profile can be left on default.
  • CAPWAP tab allows us to adjust CAPWAP & Retransmit timeouts and hardcode Primary and Secondary Controller Name and IP for N+1 designs.
  • AP tab allows us to set a Country Code, AP EAP Auth (FAST, PEAP, TLS), enable Hyperlocation, adjust BLE Beacons and AP Packet Capture settings (can capture straight to FTP location which is quite cool).
  • Management tab allows us to specify specific AP code that AP should download upon Joining the WLC, enable AP SSH access, set local mgmt user and dot1x credentials and set thresholds for detecting rogue APs.

Note: Flex Profile configuration is not required in Central Switching architecture.

6. Configure Site Tag

Now, Site Tag is slightly special πŸ™‚

You might expect that since Policy Tag was just stitching profiles together, why would Site Tag be any different?

In Central Switching mode we don’t even specify Flex Profile assignment (let’s discuss it in more details in C9800 Flex blog post). We just specify Site Tag Name, AP Join Profile and, most importantly, we specify if the site is Local (centrally switched) or not (flex). It is confusing AF! In our example, we configure Site Tag with “Enable Local Site” checked.

Site Tag configuration

Minimum config required:

  • Set Site Tag Name, specify AP Join Profile configured in previous step and check “Enable Local Site” (which means that AP will leverage central switching).

7. Configure RF Profile

Custom RF Profiles are optional but extremely helpful to have, especially if your C9800 WLC caters for sites that have different RF requirement coverage areas. Maybe some sites will have APs expected to work in a High Density or Voice environment, while most APs would be serving ‘just data’ hungry stations? We would create different RF profile for each coverage type (High Density, Voice, Data) and for each band (2.4 and 5GHz).

Minimum config required:

  • None – custom RF Profiles are optional

If you want to know more:

  • General tab is just for specifying Name, Band and Description. Make sure your RF Profile is Enabled.
  • 802.11 tab is used to specify Data Rates and MCS Rates. Disabling low data rates is crucial in most scenarios (I personally never had to allow low data rates but I’ve heard stories where others had to due to weird wireless stations requirements). In short, management and control traffic is exchanged at lowest mandatory data rate. Clients associated with our BSSID would rate shift down when moving away from the AP and when the SNR drops for any reason. Supporting low rates and setting mandatory rate too low would contribute to sticky clients behaviour, slower transmission speeds for dodgy clients sitting on low data rates, increased airtime utililisation by those clients and finally, low mandatory rates would contribute to more airtime being consumed for control and management frames, leaving less space for data transmissions. Generally, in most situations, I would set minimum mandatory rate to 12 (standard deployment) or 24 Mbps (higher density), disable all lower rates and set all higher rates to supported. Please note that proper RF design following a proper on-site survey and predictive survey (and sometimes pre-deployment survey with AP-on-a-stick) is extremely important when tweaking radio configuration! Crap in crap out, can’t mitigate shit design with good config.
  • RRM tab is quite a comprehensive topic on its own! Let’s try to keep it short. You might want to increase default number of clients per AP that generate traps. Transmit Power Control (TPC) is extremely important to use wisely and to our advantage. Normally, it’s best to try and match Tx power level of the least powerful wireless device in the network. Allowing maximium available Tx power on the AP won’t necessarily mean ‘better coverage’. Coverage works in both directions – from AP and from a client. Not matching Tx power between AP and a client might cause asymmetric traffic patterns, where client can hear the AP, but AP can no longer hear the client. You also don’t want to go too low with Tx power as the goal is to maintain as high MCS rate as possible. Normally, 2.4GHz AP max Tx should be considerably lower than 5GHz max Tx. Dynamic Channel Assignment (DCA) is another supremely important factor contributing to general performance of a WiFi network. Do we want to bond channels? Do we want to use all available 5GHz channels there? The answer is “it depends”. I’d consider using 40MHz only in smaller deployments and only if it wouldn’t contribute to excessive channel contention. Remember that doubling the channel width doubles the interference and reduces SNR by 3dB. Also, even without ‘our’ APs, RF spectrum might already be crowded so we might want to stick to 20MHz sometimes even in smaller sites. Generally speaking it seems wise to stick to 20MHz in most cases in the enterprise world (but not only!) unless sheer higher throughout is required and you fully understand implications of bonding channels. Also, newer use “Best” channel width as we’ve seen it going wild with using 80MHz in central London on sites with 20+ CCI in a busy multi-tenant building. Now, which UNII bands to use? Stick to non-DFS channels 36-48? Use 36-64? Or maybe use all 19 available (in the EU) channels? It’s hard to answer this with a ‘one size fits all’ type of an answer, but in most cases we’d use all UNII bands, unless we have some weird clients that don’t work too well with upper bands and/or don’t support 802.11k while quick roaming is important.
  • Lastly, there are features like RX SOP or Client Load Balancing in the Advanced tab. RX SOP solves half of the CCI issue by ignoring signal below configured thershold from neighbouring BSSIDs operating on the same channel on an AP level. But how about contention on the wireless station level? Exactly. It’s still there. To solve this issue better, we’d want to think about 802.11ax, where OFDMA and BSS colouring should combat that contention crap nicely. Final tip – be careful with Client Load Balancing as it might hard disassociate your precious clients, potentially making them unhappy, especially if they’re in the middle of a call or conference. I now feel we should have a separate blog and podcast about the RF Profiles and RRM. And we probably will!

8. Configure RF Tag

We are almost there! With RF Profiles sorted, we just need to stich 2.4 and 5GHz profiles together with an RF Tag.

RF Tag configuration

Using RF Profiles and RF Tags, again, is optional (but cool, so please use it).

9. Apply Tags to the APs

Yup, this is the last step.

Select APs to tag and tag them with three tags we have created above (out of which only Policy Tag is mandatory).

Apply tags to APs

Think of tagging APs as of adding them to their relevant AP Groups with specific WLANs and RF Profiles. Well, kind of πŸ™‚

That’s it. Simple. Similar to the AireOS that we all know and love so much, isn’t it? πŸ™‚

Thanks for surviving going through this lengthy post and see you in the next WiFi Ninjas Blog!

WN Blog 009 – Cisco Catalyst 9800 – Guest MAB CWA ISE Config

Hey!

Welcome to another one of our blogs on the configuration of the new series of WLC from Cisco the C9800!

In this post, I want to go through with you an issue that I ran into when configuring a Guest SSID which was using MAB with a CWA to redirect to a portal on ISE. 

A high-level overview of the C9800 -40 + 3800i APs – Local mode, Central Switching & Authentication. ISE was configured correctly and was working correctly as it should of the AireOS 5508 that I was replacing and was still working.

I had followed all the steps & configured everything in this Cisco guide apart from the BYOD flow as that was not a requirement for this project.

Cisco guide: https://community.cisco.com/t5/security-documents/ise-and-catalyst-9800-series-integration-guide/ta-p/3753060

But I was hitting two scenario issues – the first one was that I was not being redirected to the portal when connecting to the SSID but I was authenticated on ISE and had internet. The second was that I was being redirected and could authenticate with ISE by inputting the code but then not getting any internet after.

The configuration for the first scenario where I was not getting redirected but I was authenticated and had internet was that I had created the “Redirect_Webauth_ACL” and that was applied globally on the WLC – very much the same as you would on AireOS.

The configuration for the second scenario where I was being redirected but then not getting any internet was that I had applied the “Redirect_Webauth_ACL” to the “WLAN ACL” in the “Access Policy” of the Guest “Policy Profile”

So even though I had followed the documentation neither scenario was working how I would expect it to. I am going to take you through below in some screenshots the config I had applied and where as well as show you how I managed to get it working even though what I did was not clear from the Cisco guide.

One thing to call out here for when you come to write an ACL on the C9800 is to remember that they use the IOS syntax instead of what you would be used to on the AireOS WLCs.

Cisco 9800 Guide Notes
Cisco 9800 Guide Notes

From the Cisco guide this is an example of how to write the web auth redirect ACL – Cisco ACL example for the C9800:

Cisco Guide ACL
Cisco Guide ACL Example

This is where you configure the ACLs and can see that the ACL that I had configured for the web auth redirect is called “GUEST_REDIRECT_ACL”

9800 ACL Overview of all ACLs highlighting the Guest
9800 ACL Overview of all ACLs highlighting the Guest Redirect

We can have a look at the redirect ACL rule here and can see that I have specified the two ISE servers and DNS (I had previously made the ACL more specific but after many hours of troubleshooting I decided to make it bit more open)

Guest Redirect ACL
Guest Redirect ACL

Now I want to show the WLAN config where you can see the Authorisation & Authentication lists that have been specified are the two ISE servers:

Guest WLAN Security 1
Guest WLAN Security 1
Guest WLAN Security 2
Guest WLAN Security 2

Now in this scenario where I was being authenticated but not redirected, in the policy profile for the guest I had not specified the redirect ACL here.

Guest Policy Profile without ACL
Guest Policy Profile without ACL applied

When I did specify the redirect ACL in the access policy above I was now being redirected but then was not getting any internet.

Checked the guide again to make sure everything was correct which it seemed it was so left me scratching my head at this point as to why was not working as expected.

So I reached out to my security friend Aref who skills far surpass mine when it comes to security & ISE to double-check ACL config & ISE policies for the Guest Wireless MAB.

Here are a few screenshots of how ISE is configured:

ISE Config 1
ISE Config 1
ISE Config 2
ISE Config 2
ISE Config 3
ISE Config 3
ISE Config 4
ISE Config 4
ISE Config 5
ISE Config 5

So Aref confirmed that all looked good from an ISE configuration perspective – so how did we get it working I hear you ask, great question! What we had to do was to specify another ACL which we called “DENY_GUEST_INTERNAL” which in this rule we basically blocked any access to RFC 1918 but then allowed anything else and we applied this ACL to the Guest “access policy” in the “policy profile” with the redirect just applied at a global level and now we finally got redirected as well as internet!

Here are some screenshots of the other ACL, its configuration and where we applied it:

C9800 ACLs overview highlighting Deny Guest Internal
C9800 ACLs overview highlighting Deny Guest Internal
Deny Guest Internal ACL
Deny Guest Internal ACL
Policy Profile with ACL applied
Policy Profile with ACL applied

It was quite a long day of troubleshooting and trying different scenarios before we managed to finally get it working as expected and I feel that the way we did finally manage to get it working was not clear from the Cisco documentation so hopefully this can help save you guys some time if you have to configure a guest network with CWA + MAB and run into the same scenarios as I did.

Hope you enjoyed this blog on another configuration gotcha from the C9800 – as we deploy more of these and find anything else that we think may help others who will be implementing these for the first time we will post more blogs with our findings!

πŸ™‚

WN Blog 006 – Cisco Catalyst 9800 – Deployment with VMware ESXi

If you are geeky, crazy or just curious to try out first generation of Cisco products, new Catalyst 9800 Wireless LAN Controller, this guide might be useful to you πŸ™‚

Jokes aside, C9800 feels like a solid product that is quickly gaining trust of wifi pros and gains traction in the enterprises.

It is a spiritual successor to Cisco AireOS WLCs that sits on the well known IOS-XE that everyone knows and loves :] Thankfully, it has nothing to do with Converged Access, that also was IOS-XE based.

C9800 code was re-written from scratch and offers almost full features parity with its AireOS counterpart.

It’s quite flexible too, meaning you can install it in a private cloud (VMware etc.) public cloud or use it as an on-prem appliance sitting on a switch or a standalone box. All versions offer exact same functionality (with some obvious limitations, like no central data switching when used in public cloud), so you really just need to decide what’s easiest for you to deploy and integrate and think about scale.

I thought that creating an with easy-to-follow ESXi installation steps guide would be a great start!

First of all, here is my lab environment:

Lab Environment

And installation steps below:

1. Download the WLC image

  • At the time of updating this post Gibraltar-16.11.1c(ED) is the latest TAC recommended version

2. Prepare VMware networking

  • C9800-CL requires 3 interfaces – make sure to have all the required VLANs / subnets ready!
    • OOB Mgmt. – not used in Cloud (VM) WLC version, but must be assigned to a vSwitch to bring the interface up
    • Mgmt. – used to manage the WLC and for APs registration. We’re using ESXi 6.0 here, so we have to enable either all 4095 VLANs (trunk) or just one specific VLAN (access). In newer ESXi versions it is possible to allow just selected VLANs on the VMware Distributed Switch trunk. So here we’ll allow all VLANs.
    • HA (L2) – used for HA/SSO and must be configured even when used in a standalone deployment
      • It is important to put C9800 interface that we intend to use as a Redundancy Port L2 HA inter-vWLC link into a seperate, unused VLAN! Note that ‘LAB-VM-L2-HA’ Port Group sits in VLAN 666. Only my two vWLCs’ HA RP ports will be put into that group.
ESXi vSwitches Configuration

3. Spin the OVA file

  • Choose the right size (I used smallest – 1k APs)
VM Size

4. Map WLC interfaces to VM networking

  • WLC Gigabit 1 -> OOB
  • WLC Gigabit 2 -> Mgmt.
  • WLC Gigabit 3 -> HA between WLC VMs
WLC to OVF Template Network Mapping

5. Set correct security parameters on the WLC Trunk interface

  • Promiscuous mode must be set to accept, otherwise tagged traffic won’t flow correctly! This step is easy to miss but it’s very important – WLC won’t pass traffic without ticking it πŸ™‚ The C9800 uses multiple MAC address on the same VM, e.g. may be used by the SVI for wireless management (if bridge for centralised clients) or other SVI’s for loopback, etc., all of which will use different MAC address other that the one assigned to the vNIC of the VM.
  • Forged Transmits must also be set to accept, as having Forged Transmits set to reject will result in no connectivity due to host verifying the source MAC address which is transmitted by guest OS to match with the MAC address of the VM adapter. As this won’t match for C9800 instance, the ESXi host would drop the packet.
VM Trunk Promiscuous Mode and Forged Transmits

6. Boot the WLC using Virtual Console

The system will install, reboot, check if bootloader upgrade is needed, apply the config (empty at this point), etc. After few minutes, we should be presented with a familiar CLI.

Boot using Virtual Console

7. Terminate the configuration wizard

  • Would you like to enter the initial configuration dialog? [yes/no]: no
  • Would you like to terminate autoinstall? [yes]: yes

8. Set a host name

  • WLC> en
  • WLC# conf t
  • WLC(config)# hostname LAB-C9800CL

9. Add login credentials

  • LAB-C9800CL(config)# username admin privilege 15 secret <secret>

10. Configure the VLAN for wireless management interface

  • LAB-C9800CL(config)# vlan 11
  • LAB-C9800CL(config-vlan)# name wireless_management

11. Configure the SVI for wireless management interface

  • LAB-C9800CL(config)# interface vlan 11
  • LAB-C9800CL(config-if)# ip address 10.10.11.35 255.255.255.0
  • LAB-C9800CL(config-if)# no shut

12. Configure management interface

Note: since G1 is OOB, G2 is Mgmt. And G3 is HA in this VM, we’ll first configure G2 to access management plane of the WLC. All SSIDs I’m planning to use will leverage FlexConnect Local Switching (dropping data plane directly onto the switch on the AP level), therefore we don’t need to allow any other VLANs than 11 on this trunk. Still, we might want to test Central Switching, so let’s allow Wireless Users VLAN 20 (configured in later blogs) too:

  • LAB-C9800CL(config-if)# interface GigabitEthernet2
  • LAB-C9800CL(config-if)# switchport mode trunk
  • LAB-C9800CL(config-if)# switchport trunk allowed vlan 11,20
  • LAB-C9800CL(config-if)# no shut

13. Configure a default route (or a more specific route) to reach the device

  • LAB-C9800CL(config)# ip route 0.0.0.0 0.0.0.0 10.10.11.1

At this point WLC9800 Mgmt. interface should be pingable πŸ™‚

Note: you might need to shut / no shut int g2 and shut / no shut int vlan 11 for the SVI to come up!

14. Configure country code

Note: wireless network needs to be disabled first. Country code configuration forces GUI to skip the DAY 0 flow as the C9800 needs a country code to be operational. You can enter up to a maximum of 20 countries.

  • LAB-C9800CL(config)# ap dot11 5ghz shutdown
    • Disabling the 802.11a network may strand mesh APs.
  • Are you sure you want to continue? (y/n)[y]: y
  • LAB-C9800CL(config)# ap dot11 24ghz shutdown
    • Disabling the 802.11b network may strand mesh APs.
  • Are you sure you want to continue? (y/n)[y]: y
  • LAB-C9800CL(config)# ap country GB
    • Changing country code could reset channel and RRM grouping configuration. If running in RRM One-Time mode, reassign channels after this command. Check customized APs for valid channel values after this command.
  • Are you sure you want to continue? (y/n)[y]: y

Don’t forget to re-enable the radios πŸ™‚

  • LAB-C9800CL(config)# no ap dot11 5ghz shutdown
  • LAB-C9800CL(config)# no ap dot11 24ghz shutdown

Finally, validate all is up and happy:

  • LAB-C9800CL# show ap dot11 5ghz summary
  • LAB-C9800CL# show ap dot11 24ghz summary
Validate Radios Operational State

15. Create a certificate for the AP to join the virtual controller

Note: you must specify the interface for the wireless management, create certificate and verify certificate installation. If you skip the certificate/trustpoint configuration, APs will not be able to join. However, you can go to the GUI and configure it by importing the desired certificate.

  • LAB-C9800CL(config)# wireless management interface vlan 11
  • LAB-C9800CL(config)# exit
  • LAB-C9800CL# wireless config vwlc-ssc key-size 2048 signature-algo sha256 password 0 <pwd>
  • LAB-C9800CL# show wireless management trustpoint

At this point, it should be possible to access the WLC via GUI using HTTPS, IP set in step 9 and credentials set in step 7!

SSH will not work yet as the lines are not yet configured.

Credentials have already been set, so we can jump straight into the stuff that’s needed to make SSH work!

Domain name is needed for RSA key generation process.

We’ll also need to specify enable password to allow us to use privileged mode.

16. Configure access via SSH

  • LAB-C9800CL(config)# enable secret <secret>
  • LAB-C9800CL(config)# aaa new-model
  • LAB-C9800CL(config)# ip domain-name <domain-name>
  • LAB-C9800CL(config)# crypto key generate rsa general-keys modulus 1024
  • LAB-C9800CL(config)# line vty 0 530
  • LAB-C9800CL(config-line)# privilege level 15
  • LAB-C9800CL(config-line)# transport input ssh

VoilΓ ! We are now ready to register our first AP to the new, shiny and sexy WLC πŸ˜€ Well done!