9115AXI EWC caches mDNS from VLANs but won't serve wireless clients

[NS1960]

I have a Catalyst 9115AXI running an EWC.  I've followed the instructions here:

https://www.cisco.com/c/en/us/td/docs/wireless/controller/ewc/17-3/config-guide/ewc_cg_17_3/m_mdns_gateway.html

I am able to see, in the EWC, the mDNS services that are cached (i.e., "Monitoring" tab) but the EWC won't serve the advertisements to wireless clients. To be clear, I've configured:

(1) A mDNS flex profile with assigned wired VLANs

(2) Applied the mDNS flex profile to my flex tag/profile (I only have 1 in use)

(3) I've configured an mDNS service policy (which includes IN and OUT lists, which in turn include ALL services)

(4) I've enabled the *global* mDNS gateway and assigned the service policy in (3) to it.

(5) I can see the cached services - they show up in Monitoring -> mDNS

(6) I have configured a WLAN which otherwise works, and have configured the WLAN to be in "Gateway" mDNS mode

(7) I have modified the WLAN policy tag to include the mDNS service policy configured in (3).

The wired service is on (wired) VLAN 8, and I'm trying to broadcast the advertisement over to (wireless) VLAN 10 via the WLAN which is on VLAN 10 (and verified to be working correctly as such). 

Any idea or help is most appreciated.

[marce1000]

 -  Review the 9115AXI EWC  configuration with the CLI command : show  tech   wireless , have the output analyzed by  https://cway.cisco.com/tools/WirelessAnalyzer/  , please note do not use classical show tech-support (short version) , use the command denoted in green for Wireless Analyzer.               Checkout all advisories!

                     You may also find these commands useful :
        show ip mroute
        show ap multicast mom
        show mdns-sd cache
        show mdns-sd default-service-list

 M.

[NS1960]

Thanks - the tool you recommended indicates the problem with mDNS is twofold:

mDNS: WLAN is using mDNS gateway functionality, but not corresponding SVI Interface detected. WLANs/Policies: <name>/ <name>

Action: Add: Define an Interface vlan (SVI) for all vlans where mDNS gateway functionality is required. This check may not apply on AAA override scenarios

Interfaces: Interface SVI (vlan) detected, but no corresponding vlan entry configured. Interfaces: Vlan6,Vlan8,Vlan10

Action: Add: vlan NUMBER to the configuration. If this is not corrected, the SVI interface will remain down

I have, however, added the SVIs - I have assigned addresses to them and I can see them in the EWC configuration.  Moreover, the interface is UP (from CLI). 

This document seems to suggest that the EWC does not support SVIs - which is puzzling, if true - (why can it be configured if not supported, and it further suggests that mDNS gateway mode can never work!)

https://www.cisco.com/c/en/us/support/docs/wireless/embedded-wireless-controller-on-catalyst-access-points/215303-embedded-wireless-controller-conversion.html#anc2

Am I missing something?

[marce1000]

 >...This document seems to suggest that the EWC does not support SVIs - which is puzzling, if true - (why can it be configured if not supported, and it further suggests that mDNS gateway mode can never work!)
         - The document is slightly incorrect , the EWC on AP cannot use more then one SVI , probably the software does not differ enough to include this restriction on the EWC platform. You could try your design on a 9800 Cloud version (for testing). Background : on the EWC AP it is the AP OS that provide it's dataplane to the controller code  running  in a container, (hence the SVI restriction)

 M.

[Rich R]

I'd agree with your interpretation of the docs - that mDNS gateway is effectively unsupported on EWC because WLC SVI is a requirement but is not supported on EWC.  Marce's idea of using 9800-CL is probably your best option.

[Rahul Kachalia]

Hello,

If EWC AP is connected to Catalyst 9000 series switches, then instead of flood-n-learn based mDNS model you may enable Unicast-mode solution between Wired and Wireless. 

You may want to completely disable mDNS gateway on EWC and implement mDNS gateway on Catalyst 9000 series switch. Following is the only config you may need on switch running 17.6.2 and above:

!

mdns-gateway

 mode service-peer

 active-query timer 1

!

vlan configuration 8, 10

  mdns-sd gateway

!

Following are some documentations that you may refer:

Quick Configuration : Look for last section it is identical configuration for FlexConnect or EWC:

https://www.cisco.com/c/en/us/solutions/collateral/enterprise-networks/dna-service-bonjour-og.pdf

And following is deployment guide:

https://www.cisco.com/c/en/us/solutions/collateral/enterprise-networks/guide-c07-743788.html

thanks,

rahul.