Asterisks in the DHCP Lease table

[Mr Tvardovsky]

I am sorry if this is a silly question or if it had been answered somewhere else already. But could someone kindly explain to me the asterisks in this picture:

This comes from the 'System Log - DHCP leases' tab. I wonder why some clients are described with their real names, where 'real' means the same ones as on the client list in the Network Map, while others are just marked with an asterisk. In the Network Map some of these 'asterisk clients' have custom names created by me, some have been left with the default ones - there seems to be no rule.

Any hints?

 

[L&LD]

There is no need to hide private IP addresses that begin with 192.168.*.*. These are identical (and unreachable for anyone outside of the network) for all.

Was the router rebooted while the nodes were not? Are the devices on one of the nodes? Are you running AP's or an AiMesh system?

 

[Mr Tvardovsky]

Was the router rebooted while the nodes were not? Are the devices on one of the nodes? Are you running AP's or an AiMesh system?

Hi L&LD. I’m running the ‘regular’ APs and not the AIMesh. There is a number of devices (smartphones and laptops) that roam a lot between the APs and a few (smart TV, XBOX, sound system) that remain permanently attached to a single AP. I have rebooted and actually factory reset both the router and the APs multiple times, but these asterisks consistently remain there. As a matter of fact, I only noticed them because they showed up in the NextDNS logs.

 

[L&LD]

Was a saved backup config file used after the full resets? Was the JFFS partition formatted properly? Are you using amtm and/or any other custom scripts?

 

[ColinTaylor]

Pick one of the devices that has an asterisk as a hostname and power it off (not standby) and on again. Does its hostname now appear?

 

[john9527]

Possibly another artifact of the 'privacy' MAC changes (are these primarily Apple devices?). I think DHCP won't assign a host name if it's in the DCHP reservations associated with a different MAC

EDIT: IIRC there will be a syslog entry telling you that happened.

 

[RMerlin]

Clients that don't specify a hostname when requesting a lease will be shown with an "*" by dnsmasq since it has no idea what hostname the client is using.

 

[Mr Tvardovsky]

Was a saved backup config file used after the full resets? Was the JFFS partition formatted properly? Are you using amtm and/or any other custom scripts?

I never use saved backup configs; it's more fun to enter them manually Yes, whenever I do a factory reset, I always format JFFS partition, too. I do us amtm, led control and NextDNS CLI. Sadly had to turn Skynet off, because of too many false positives recently.

 

[Mr Tvardovsky]

Pick one of the devices that has an asterisk as a hostname and power it off (not standby) and on again. Does its hostname now appear?

Thanks for the suggestion, but unfortunately the asterisk is still there.

 

[Mr Tvardovsky]

Possibly another artifact of the 'privacy' MAC changes (are these primarily Apple devices?). I think DHCP won't assign a host name if it's in the DCHP reservations associated with a different MAC

EDIT: IIRC there will be a syslog entry telling you that happened.

Thank you, John. Interestingly, Apple devices are among the ones that behave perfectly properly - they never get 'asterisksized' (and BTW, I never use the MAC change option). But when you asked this question, I realized there is another pattern: my Yamaha amplifier and 2 connected Yamaha speakers seem to always show up with asterisks and the same is true about my MOCA adapters and my wifi Canon printer. I believe this validates RMerlin's verdict in the post #9. Which is no surprise to anybody, I guess ;-)

 

[Mr Tvardovsky]

Clients that don't specify a hostname when requesting a lease will be shown with an "*" by dnsmasq since it has no idea what hostname the client is using.

Hi RMerlin, thank you for your attention. It totally makes sense to me that the root cause of this is on the device side. Especially now when John's question made me aware there are some devices which consistently end up with an "*". May I have 2 follow-up questions to that:
1) Why do these devices have an asterisk in the DHCP Lease table, but show up with a name in the Network Map - and not with a name that I would give them? Wouldn't it mean that at some point they actually do specify a hostname?
2) Is there a way how to edit these asterisks in the DHCP table?
I am sorry to bother you with it and I fully realize that it's not a matter of life and death - otherwise my setup is rock solid and I can't be grateful enough for your fantastic firmware which made me abandon the DD-WRT world The only practical reason why I dig in it is that these asterisks are transferred to the NextDNS logs and I can't easily recognize my devices there.

 

[ColinTaylor]

2) Is there a way how to edit these asterisks in the DHCP table?

You can't directly edit those names because (as Merlin said) they are supplied by the client. However, there is a way around it. If you create a DHCP reservation for a device (LAN > DHCP Server > Manually Assigned IP around the DHCP list) you can override the hostname supplied (or not) by the client with one of your own choosing. I do this for some IoT devices that don't have sensible hostnames (e.g. android-1f432c45a9).

 

[Mr Tvardovsky]

Thank you very much @ColinTaylor. Sounds like a sensible workaround.

Greetings from Poland

 

[RMerlin]

1) Why do these devices have an asterisk in the DHCP Lease table, but show up with a name in the Network Map - and not with a name that I would give them? Wouldn't it mean that at some point they actually do specify a hostname?

The networkmap "name" isn't necessarily a network hostname, it can be just a descriptive label that was deduced from probing the device, analyzing its MAC address, etc... While the DHCP list page will always report an actual hostname.

There is nothing to edit there, the DHCP lease simply reports what the DHCP server knows. Nothing more.

 

[Mr Tvardovsky]

All clear. Thank you, @RMerlin !