Not all devices are listed in DHCP

Gertjan

Hi.

Easy !

Restart - or disconnect a couple of seconds - these devices.
Their DHCP client will ask again for a lease.

firefox

I've tried it now
They still do not appear
I unplugged them from the network and the electricity for 10 minutes

johnpoz

Did you see them ask for an IP? In the dhcp log?

If not - then there are possibilities.. They are set static on the device, they are behind a nat.. .Your AP you mention really doing nat vs being an AP. They are still using an old lease from previous setup? You have a another dhcp on the network, etc.

They are not working on your network.

If the dhcpd handed out an IP, it would be in the lease table, and it would be in the dhcpd log.

firefox

Some of them have a static address
Like the access points
Printers
The switch

TVs do not have
And they don't show up either

I entered the graphical interface of two access points
And I copied the mac address to pfsense
And I added to the static addresses

It's just two devices
On other devices, I can't find where to see the device's mac address

Is there a way to see their connected devices and mac addresses ?

johnpoz

Go into your TV... You sure its set for dhcp?

You sure don't need to add a reservation for dhcpd clients to show up in the leases tab.

What TV do you have, it should list the mac address under some sort of system info, or network info..

If your devices are setup static on the device - then no it wouldn't have a lease, so no it wouldn't show up in the leases tab. If your going to set static on the device then you don't need to setup a reservation for that mac.. Unless your just using it for info and name resolution while you register reservations.

If you want to resolve them by name, you could just setup a host override.

If your looking for their mac, you could always ping their IP, and then look in your arp table.

firefox

Televisions probably have memory or something
I went into network setting of televisions
And I clicked Find a Network
It has found and is now appearing

There are three more devices that do not appear
Access point and two television adapter
The access point does not appear in the table you specified (arp)

The ARP table lists three devices with three IPs
That do not appear in IP leasing
Not static or dynamic

i try that in terminal

nmap -n -sP  192.168.1.1/24  -oG -
# Nmap 7.60 scan initiated Sun May 10 16:26:53 2020 as: nmap -n -sP -oG - 192.168.1.1/24
Host: 192.168.1.1 ()	Status: Up
Host: 192.168.1.2 ()	Status: Up
Host: 192.168.1.3 ()	Status: Up
Host: 192.168.1.5 ()	Status: Up
Host: 192.168.1.7 ()	Status: Up
Host: 192.168.1.8 ()	Status: Up
Host: 192.168.1.9 ()	Status: Up
Host: 192.168.1.10 ()	Status: Up
Host: 192.168.1.23 ()	Status: Up
Host: 192.168.1.25 ()	Status: Up
Host: 192.168.1.26 ()	Status: Up
Host: 192.168.1.27 ()	Status: Up
# Nmap done at Sun May 10 16:27:00 2020 -- 256 IP addresses (12 hosts up) scanned in 7.09 seconds

access point has a ping
And it works
But no it is not listed on the terminal list

ping 192.168.1.25
PING 192.168.1.25 (192.168.1.25) 56(84) bytes of data.
64 bytes from 192.168.1.25: icmp_seq=1 ttl=255 time=0.508 ms
64 bytes from 192.168.1.25: icmp_seq=2 ttl=255 time=0.485 ms
64 bytes from 192.168.1.25: icmp_seq=3 ttl=255 time=0.692 ms
64 bytes from 192.168.1.25: icmp_seq=4 ttl=255 time=0.352 ms

johnpoz

@firefox said in Not all devices are listed in DHCP:

But no it is not listed on the terminal list

Yes it is

Host: 192.168.1.25 () Status: Up

I think your confused as to what will be in the dhcp leases tab.. ONLY devices that have actually gotten leases from the dhcp server of pfsense will be listed there. Or things you have created a dhcp reservation for..

So box you set a static for on the device itself will never show up in the leases tab, because it never gets a lease..

If you want to know what pfsense knows about, this would be the arp table... But only things that have talked to pfsense in the last 20 minutes are so would be in there as well.. This is the default arp cache timer..

So box that is on your network, not talking to pfsense, not getting a lease from pfsense dhcp server. Would not be listed in either dhcp leases or arp table.

firefox

@johnpoz said in Not all devices are listed in DHCP:

@firefox said in Not all devices are listed in DHCP:

But no it is not listed on the terminal list

Yes it is

Host: 192.168.1.25 () Status: Up

sorry I missed it

If you want to know what pfsense knows about, this would be the arp table... But only things that have talked to pfsense in the last 20 minutes are so would be in there as well.. This is the default arp cache timer..

So box that is on your network, not talking to pfsense, not getting a lease from pfsense dhcp server. Would not be listed in either dhcp leases or arp table.

I'll check again another hour
I will see if it appears in the ARP table

johnpoz

@firefox said in Not all devices are listed in DHCP:

I'll check again another hour

It might not be there, again the arp table cache is only 20 minutes.

If you just pinged it from pfsense, it would be in the arp table!!

Keep in mind there is nothing that shows you everything that is on your network in pfsense.. Only things that have gotten a lease from pfsense and lease is still active, you have set a reservation for. Arp table will list things that have talked to pfsense in the last 20 minutes.

I can put a printer lets on my network, and if its static set on the printer, and the printer has no reason to talk to the gateway (pfsense) it pfsense wouldn't list it.. Even if devices on your network were printing to it, etc.

Lets say the printer tried to talk to the internet, via pfsense - then yes it would be in the arp table. But if it then goes to sleep or something, pfsense would drop this from its arp table in 20 minutes.

firefox

@johnpoz said in Not all devices are listed in DHCP:

If you just pinged it from pfsense, it would be in the arp table!!

it worked
Thanks