# DHCP assignment issue with only certain devices

**URL:** <https://discourse.pi-hole.net/t/dhcp-assignment-issue-with-only-certain-devices/37812>\
**Category:** Community Help\
**Created:** [August 30, 2020, 7:20pm UTC](https://discourse.pi-hole.net/t/dhcp-assignment-issue-with-only-certain-devices/37812 "2020-08-30T19:20:32Z")\
**Posts on this page:** 8\
**Page:** 1

<div class="post-metadata">

**Author:** ![Andrew\_Boie](https://discourse-cdn.pi-hole.net/user_avatar/discourse.pi-hole.net/andrew_boie/32/18330_2.png) [@Andrew\_Boie](https://discourse.pi-hole.net/u/Andrew_Boie)\
**Post date:** [August 30, 2020, 7:20pm UTC](https://discourse.pi-hole.net/t/dhcp-assignment-issue-with-only-certain-devices/37812/1 "2020-08-30T19:20:32Z")

</div>

## Expected Behaviour:

I expect the pihole DHCP server (which I understand is actually dnsmasq) to successfully hand out IP addresses to all the devices on my network.

## Actual Behaviour:

Some devices just can't seem to get an IP address. The following log is typical, it seems like it is trying to hand out an address, but the log is spammed with requests, the assignment just doesn't take for some reason.

This never happens with a PC or laptop.  
This only seems to happen with certain embedded hardware devices. All are using wired Ethernet. So far I have seen it with:

- URayCoder H.264 Live HDMI Video Encoder
- Digital Logger Pro Switch (web power switch)
- Pioneer XDJ-1000 MK2 (it's a DJ player)  
Other embedded devices on my LAN (my stereo receiver, an assortment of LIFX light bulbs, and some ESP32-based smart power switches) seem to work just fine.

I worked around it for the first two devices by assigning a static IP, but the Pioneer XDJ was a dealbreaker as it has no settings interface, so here I am 🙂

Here's what I see in "tail -f /var/log/pihole.log | grep dhcp" when I connect the XDJ:

Aug 30 19:56:21 dnsmasq-dhcp[918]: DHCPREQUEST(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:21 dnsmasq-dhcp[918]: DHCPACK(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:26 dnsmasq-dhcp[918]: DHCPDISCOVER(eth0) 1c:f2:9a:7c:b3:74  
Aug 30 19:56:26 dnsmasq-dhcp[918]: DHCPOFFER(eth0) 192.168.86.73 1c:f2:9a:7c:b3:74  
Aug 30 19:56:26 dnsmasq-dhcp[918]: DHCPDISCOVER(eth0) c8:3d:fc:04:16:23  
Aug 30 19:56:26 dnsmasq-dhcp[918]: DHCPOFFER(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:26 dnsmasq-dhcp[918]: DHCPDISCOVER(eth0) c8:3d:fc:04:16:23  
Aug 30 19:56:26 dnsmasq-dhcp[918]: DHCPOFFER(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:26 dnsmasq-dhcp[918]: DHCPREQUEST(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:26 dnsmasq-dhcp[918]: DHCPACK(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:28 dnsmasq-dhcp[918]: DHCPDISCOVER(eth0) c8:3d:fc:04:16:23  
Aug 30 19:56:28 dnsmasq-dhcp[918]: DHCPOFFER(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:28 dnsmasq-dhcp[918]: DHCPREQUEST(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:28 dnsmasq-dhcp[918]: DHCPACK(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:30 dnsmasq-dhcp[918]: DHCPDISCOVER(eth0) c8:3d:fc:04:16:23  
Aug 30 19:56:30 dnsmasq-dhcp[918]: DHCPOFFER(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:30 dnsmasq-dhcp[918]: DHCPREQUEST(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:30 dnsmasq-dhcp[918]: DHCPACK(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:32 dnsmasq-dhcp[918]: DHCPDISCOVER(eth0) c8:3d:fc:04:16:23  
Aug 30 19:56:32 dnsmasq-dhcp[918]: DHCPOFFER(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:32 dnsmasq-dhcp[918]: DHCPREQUEST(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:32 dnsmasq-dhcp[918]: DHCPACK(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:34 dnsmasq-dhcp[918]: DHCPDISCOVER(eth0) c8:3d:fc:04:16:23  
Aug 30 19:56:34 dnsmasq-dhcp[918]: DHCPOFFER(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:34 dnsmasq-dhcp[918]: DHCPREQUEST(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:34 dnsmasq-dhcp[918]: DHCPACK(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:36 dnsmasq-dhcp[918]: DHCPDISCOVER(eth0) c8:3d:fc:04:16:23  
Aug 30 19:56:36 dnsmasq-dhcp[918]: DHCPOFFER(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:36 dnsmasq-dhcp[918]: DHCPREQUEST(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:36 dnsmasq-dhcp[918]: DHCPACK(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:36 dnsmasq-dhcp[918]: DHCPDISCOVER(eth0) cc:98:8b:72:2d:20  
Aug 30 19:56:36 dnsmasq-dhcp[918]: DHCPOFFER(eth0) 192.168.86.46 cc:98:8b:72:2d:20  
Aug 30 19:56:36 dnsmasq-dhcp[918]: DHCPREQUEST(eth0) 192.168.86.46 cc:98:8b:72:2d:20  
Aug 30 19:56:36 dnsmasq-dhcp[918]: DHCPACK(eth0) 192.168.86.46 cc:98:8b:72:2d:20  
Aug 30 19:56:36 dnsmasq-dhcp[918]: DHCPDISCOVER(eth0) cc:98:8b:72:2d:20  
Aug 30 19:56:36 dnsmasq-dhcp[918]: DHCPOFFER(eth0) 192.168.86.46 cc:98:8b:72:2d:20  
Aug 30 19:56:36 dnsmasq-dhcp[918]: DHCPREQUEST(eth0) 192.168.86.46 cc:98:8b:72:2d:20  
Aug 30 19:56:36 dnsmasq-dhcp[918]: DHCPACK(eth0) 192.168.86.46 cc:98:8b:72:2d:20  
Aug 30 19:56:38 dnsmasq-dhcp[918]: DHCPDISCOVER(eth0) c8:3d:fc:04:16:23  
Aug 30 19:56:38 dnsmasq-dhcp[918]: DHCPOFFER(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:38 dnsmasq-dhcp[918]: DHCPREQUEST(eth0) 192.168.86.114 c8:3d:fc:04:16:23  
Aug 30 19:56:38 dnsmasq-dhcp[918]: DHCPACK(eth0) 192.168.86.114 c8:3d:fc:04:16:23

## Debug Token:

[https://tricorder.pi-hole.net/av2to9jwb6](https://tricorder.pi-hole.net/av2to9jwb6)

---

<div class="post-metadata">

**Author:** ![deHakkelaar](https://discourse-cdn.pi-hole.net/user_avatar/discourse.pi-hole.net/dehakkelaar/32/674_2.png) [@deHakkelaar](https://discourse.pi-hole.net/u/deHakkelaar)\
**Post date:** [August 30, 2020, 7:54pm UTC](https://discourse.pi-hole.net/t/dhcp-assignment-issue-with-only-certain-devices/37812/2 "2020-08-30T19:54:44Z")

</div>

Make sure no other DHCP server is active on your network!  
You could also check with below:

```auto
pi@ph5:~ $ ip -br -4 a s eth0
eth0 UP 10.0.0.4/24

```

* * *

```auto
pi@ph5:~ $ sudo nmap -e eth0 --script broadcast-dhcp-discover
Starting Nmap 7.70 ( https://nmap.org ) at 2020-08-30 21:42 CEST
Pre-scan script results:
| broadcast-dhcp-discover:
| Response 1 of 1:
| IP Offered: 10.0.0.29
| DHCP Message Type: DHCPOFFER
| Server Identifier: 10.0.0.4
| IP Address Lease Time: 2m00s
| Renewal Time Value: 1m00s
| Rebinding Time Value: 1m45s
| Subnet Mask: 255.255.255.0
| Broadcast Address: 10.0.0.255
| Domain Name Server: 10.0.0.4
| Domain Name: dehakkleaar.nl
|_ Router: 10.0.0.1
WARNING: No targets were specified, so 0 hosts scanned.
Nmap done: 0 IP addresses (0 hosts up) scanned in 2.89 seconds

```

You can install `nmap` on the Pi-hole host with below:

`sudo apt install nmap`

You might also want to redact the MAC addresses from the `tail` output you posted above.  
We are only interested in the first three octets eg. `c8:3d:fc:xx:xx:xx` that define the vendor:

```auto
pi@ph5:~ $ sqlite3 /etc/pihole/macvendor.db "SELECT mac,vendor FROM macvendor WHERE mac LIKE 'c8:3d:fc'"
C8:3D:FC|AlphaTheta Corporation

```

---

<div class="post-metadata">

**Author:** ![Andrew\_Boie](https://discourse-cdn.pi-hole.net/user_avatar/discourse.pi-hole.net/andrew_boie/32/18330_2.png) [@Andrew\_Boie](https://discourse.pi-hole.net/u/Andrew_Boie)\
**Post date:** [September 1, 2020, 12:22am UTC](https://discourse.pi-hole.net/t/dhcp-assignment-issue-with-only-certain-devices/37812/3 "2020-09-01T00:22:46Z")

</div>

Yep, after trying that out, turns out multiple DHCP was the problem.

My wifi router is a Google Home, the kind with mesh networking. It has no option at all to disable its DHCP server. On some site (can't remember where) it was recommended to just restrict the DCHP range of the Google Wifi to one IP address for the pihole (192.168.86.254). This worked for the most part when I set it up a long time ago...but seems this is root cause of a few devices having fits.

Swapping routers (I'm using an Asus RT-AX3000 now) did the job.

Thanks for your help!

---

<div class="post-metadata">

**Author:** ![deHakkelaar](https://discourse-cdn.pi-hole.net/user_avatar/discourse.pi-hole.net/dehakkelaar/32/674_2.png) [@deHakkelaar](https://discourse.pi-hole.net/u/deHakkelaar)\
**Post date:** [September 1, 2020, 10:31pm UTC](https://discourse.pi-hole.net/t/dhcp-assignment-issue-with-only-certain-devices/37812/4 "2020-09-01T22:31:17Z")

</div>

Are you using the Asus router for DHCP now ?  
Asus routers are known for pushing their own IP for DNS regardless of what DNS servers are configured in the DHCP--\>DNS section on the router.  
If so, you can check the "Domain Name Server" section from the `nmap` output to validate.

> [@Why should Pi-hole be my only DNS server?](https://discourse.pi-hole.net/t/why-should-pi-hole-be-my-only-dns-server/3376):
>
> Reduced Ad Blocking Capability The main reason you should Pi-hole as your only DNS server is that you will see increased performance in the blocking of ads. If you have two DNS servers (Pi-hole and something else), your network clients may not always query Pi-hole for name resolution. If a query happens to be answered from a non-Pi-hole DNS server, your block lists will not apply (since that DNS server doesn't know about them). All Queries Need To Go Through Pi-hole First Since other DNS serv…

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<div class="post-metadata">

**Author:** ![Bucking\_Horn](https://discourse-cdn.pi-hole.net/user_avatar/discourse.pi-hole.net/bucking_horn/32/18719_2.png) [@Bucking\_Horn](https://discourse.pi-hole.net/u/Bucking_Horn)\
**Post date:** [September 4, 2020, 1:14pm UTC](https://discourse.pi-hole.net/t/dhcp-assignment-issue-with-only-certain-devices/37812/5 "2020-09-04T13:14:07Z")

</div>

14 posts were split to a new topic: [Reliably detect all DHCP servers on a network?](https://discourse.pi-hole.net/t/reliably-detect-all-dhcp-servers-on-a-network/37981)

---

<div class="post-metadata">

**Author:** ![Andrew\_Boie](https://discourse-cdn.pi-hole.net/user_avatar/discourse.pi-hole.net/andrew_boie/32/18330_2.png) [@Andrew\_Boie](https://discourse.pi-hole.net/u/Andrew_Boie)\
**Post date:** [September 2, 2020, 7:39pm UTC](https://discourse.pi-hole.net/t/dhcp-assignment-issue-with-only-certain-devices/37812/7 "2020-09-02T19:39:34Z")

</div>

> Are you using the Asus router for DHCP now ?

No, I disabled it and am using the pihole for DHCP. Working well so far. I did get a warning that disabling DHCP on the router would prevent the mesh network capability but I am not using this feature.

---

<div class="post-metadata">

**Author:** ![Bucking\_Horn](https://discourse-cdn.pi-hole.net/user_avatar/discourse.pi-hole.net/bucking_horn/32/18719_2.png) [@Bucking\_Horn](https://discourse.pi-hole.net/u/Bucking_Horn)\
**Post date:** [September 4, 2020, 8:52pm UTC](https://discourse.pi-hole.net/t/dhcp-assignment-issue-with-only-certain-devices/37812/9 "2020-09-04T20:52:05Z")

</div>

A post was merged into an existing topic: [Reliably detect all DHCP servers on a network?](https://discourse.pi-hole.net/t/reliably-detect-all-dhcp-servers-on-a-network/37981/15)

---

<div class="post-metadata">

**Author:** ![system](https://discourse.pi-hole.net/uploads/default/original/3X/7/c/7c8792f649eeb921c5d2b4c41564ffa873d9a2b8.png) [@system](https://discourse.pi-hole.net/u/system)\
**Post date:** [September 26, 2020, 8:00am UTC](https://discourse.pi-hole.net/t/dhcp-assignment-issue-with-only-certain-devices/37812/12 "2020-09-26T08:00:27Z")

</div>

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