Unifi AP hostname no update

You need to initiate a provisioning of a Ubiquiti Unifi access point to make active a change to the Alias.  This can be done by changing something like the channel used in the 2.4 or 5 Ghz spectrum or modifying radio signal strength.

Restarting the access point is not sufficient.

Until you do this, running info form the BusyBox CLI on the access point reflects the old alias. Similarily, attempting to Add Device using SNMP in LibreNMS will fail too.


Dynamic DNS Updates

Non domain dhcp clients do not get a DNS record when they receive a lease.

Add new user with a password that does not expire. Add member to the DHCP Administrators security group.

Open DHCP console, connect to DHCP server and access IPv4 properties. Under the Advanced tab, specify the credentials you specified earlier.

I found restarting the DHCP and DNS services had no effect, so in my experience rebooting the Windows Server 2012 R2 box that hosted DNS and DHCP did the trick.

Now I see various wireless clients, including non-domain joined windows laptop and iPhones with names that now resolve to IP addresses.

It is worth a mention: I disabled secure updates.

Apparently you can acheive the same thing by adding the DHCP server to the DNSUpdateProxy group. But, this is a security risk if the box that DHCP is running on is also a domain controller. That is because the AD records can be written to by anyone. OpenACLOnProxyUpdate setting can mitigate the risk. The recommended solution is to specify credentials for the dynamic DNS update.

Ubiquiti EdgeOS Find MAC Address

On a core layer switch I wanted to learn what port was connected to an access layer switch. This would enable me to add the missing documentation of the network topology.

First find the MAC address of the access layer switch. We’ll search for this value in the IP stack’s ARP table. To do this, jump into Unifi and select your access layer switch. From the Properties window, select the Configuration tab, then expand Debug Terminal. Click Open Terminal and when the terminal opens run the info command from the BusyBox CLI. This will reveal a  few details about the switch, including the MAC address of the management interface.

With the MAC address in hand we will search for it from the Edgeswitch CLI.

(UBNT EdgeSwitch) #show mac-addr-table 04:18:d6:f0:d2:34

VLAN ID  MAC Address         Interface              IfIndex  Status
-------  ------------------  ---------------------  -------  ------------
1        04:18:D6:F0:D2:34   0/8                    8        Learned

(UBNT EdgeSwitch) #

On the other hand, you can find the MAC address of a device on the other end of a link by specifying an interface instead.

(UBNT EdgeSwitch) #show mac-addr-table interface 0/16
   MAC Address      VLAN ID      Status

-----------------  ---------  ------------
D4:F4:BE:1F:99:11     1        Learned

(UBNT EdgeSwitch) #

more to come….

SCCM No Task Sequence Available For This Computer

This is caused by one or more workstations in the network having the same SMBIOS GUID, aka System UUID in SCCM terms.

On the workstation that cannot run a Task Sequence, launch a command prompt in WinPE by pressing SHIFT + F10 and drop into the WMIC CLI by issuing this command:


At the prompt wmic:root\cli>, get the SMBIOS GUID by issuing:

csproduct get uuid

Paste this into a new text document using notepad and then transfer to SCCM. We’ll build a query using the System UUID to find the conflicting workstations.

net use j: \\sccmServer\share /user:domainName\userName

We’ll enter that System UUID into a Device Collection Query:

select SMS_R_SYSTEM.ResourceID,SMS_R_SYSTEM.ResourceType,SMS_R_SYSTEM.Name,SMS_R_SYSTEM.SMSUniqueIdentifier,SMS_R_SYSTEM.ResourceDomainORWorkgroup,SMS_R_SYSTEM.Client from SMS_R_System where SMS_R_System.SMBIOSGUID = “4C4C4544-0053-5810-8059-B2C04F433832″


Windows 10 Add User

This task fails when using the Settings app, but there is a work around.

Tap Windows Key + R to open the Run dialog window.

Run this command:

control userpasswords2