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Cisco AP DHCP Option 43 with Infoblox


First of all this is probably more Infoblox related but i would like to know if you have any tips.
We trying to achieve assigning dhcp option 43 based on VCI

Rules are simple

If the VCI is "ciscopnp" then it is a switch and we need to return the DNAC IP address
option 43 ACSII value "5A1N;B2;K4;I10.93.4.40;J80"

If the VCI contains something else (or if the VCI starts with "Cisco AP") then it is a wifi AP and we need to return the IP address of the wireless controller
option 43 value hex: f1:08:0a:5d:04:14:0a:dd:04:14

Without the logic filters and only one DHCP options it works correctly for both AP and Switches. But with the logic filters it works only for switches. When we setup logic filters for AP some 2b0a prefix appears in the string value.
Visible on the left image of wireshark dumps.

Im trying to find out origin of the 2b0a prefix does any have some tips?
Thank you in advance


Just including the logic filters




1 Accepted Solution

Accepted Solutions

I use bit of work around instead of the option 43, i used 241 with decimal format and the onboarding is working now.

View solution in original post

5 Replies 5

Flavio Miranda
VIP Mentor VIP Mentor
VIP Mentor


thank you yes i post it also on the infoblox community but we didnt find the solution yet so im trying luck also here if someone had similar issue.


I have four suggestions
1) AP's can also be provisioned by DNA Center for this the Cisco AP's may also use VCI "ciscopnp"!!!
    so this is not enough to determine the device is a switch.

2)  the order that the filters have been created in Infoblox may be important
    or the 2b0a may denote the rule-number in the filter; or there may even be TWO responses!
3) try changing the rules in Infoblox filter so that VCI is not only "Cisco AP" but the full AP model
   vendor-class-identifier="Cisco AP C9120AX" OR vendor-class-identifier="Cisco AP c2800"  .......
4) "Cisco AP" is length 8 not 7


Thank you for response

1) yes but the switches are working OK now
2)i will also try to modify that
3) yes thats good point i will create individual rules for AP models
4) solved by edit in point3


I use bit of work around instead of the option 43, i used 241 with decimal format and the onboarding is working now.

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