C9800-40 MDNS_CACHE: Cannot have more than 100 services per client

[Konstantin Kabassanov]

Hello,

In previous wireless controllers (ex. Wism2 v. 8.5.151.0) , mdns gateway was grouping service providers by mdns service name and was allowing more than 100 entries from the same mac address. It seems that in recent IOSXE version on C9800, where services are grouped by client (ie mac address), mdns gateway cache is limited to 100 services per client and drops any additional announcement received by the controller. 

2024/08/19 14:45:19.797326473 {wncd_x_R0-0}{1}: [mdns] [15244]: (ERR): MDNS_CACHE: Cannot have more than 100 services per client. Drop announcement
2024/08/19 14:45:19.797329783 {wncd_x_R0-0}{1}: [mdns] [15244]: (ERR): MDNS_DB: Failed to add entry
2024/08/19 14:45:19.797339591 {wncd_x_R0-0}{1}: [mdns] [15244]: (ERR): [MAC:aa02.0000.0f0f]PTR record add/update failed
2024/08/19 14:45:19.797339989 {wncd_x_R0-0}{1}: [mdns] [15244]: (ERR): Error during processing of Answer Section

I did not find any mention of this limitation anywhere... Have you already seen anything about this?

Thanks.

[marce1000]

   - Check your controller software version and evaluate against : 
              https://software.cisco.com/download/home/286316412/type/282046477/release/Dublin-17.12.3
                                      Always good practice when dealing with that kind of issues

  + Always advised :   Have an overall checkup of the  9800 controller's configuration with the CLI command
      show tech wireless and feed the output from that into Wireless Config Analyzer
      use the full command as denoted in green , do not use a simple show tech as input for this procedure

    I don't think the above will resolve this , but  look for other related stuff in the advisories  , if any.

 M.

[Konstantin Kabassanov]

Thanks for your reply. Unfortunately, there is nothing in the release notes (17.9.5). And no related commands are available (or listed) in the mdns-sd gateway configuration submenu... Sometimes, there are hidden commands, but the challenge is to find them...

[marce1000]

   - Ref : https://www.cisco.com/c/en/us/products/collateral/ios-nx-os-software/ios-xe-17/ios-xe-17-9-x-eol.html
             17.9.x is becoming EOL , another good reason to go to 17.12.3

            As far as Release Notes is concerned not all deep technical improvements get documented , 
            neither in Resolved Caveats , that is the reason I was suggesting it , 

 M.

[Konstantin Kabassanov]

Not sure when Dublin-17.12.3(ED) appeared as suggested, but Cupertino-17.9.5(MD) is also a suggested release for the moment...

Have to check what additional surprises it contains.

[marce1000]

  - Check picture below , it is gold-starred too , I know that 17.9.5 'still has the star' too , but I was pointing to it because of your issue(s) : for suprises the idea from the star is to have the opposite , but you never know indeed.....

 M.

[Konstantin Kabassanov]

Not documented limitation on 9800 (and other actual Cisco Wireless Controllers?) and no workaround...