Hello!
I am trying to configure pihole for a specific router. This does not have a DHCP option to send to a DNS. In this case I have to deactivate the Router DHCP and activate the one in pihole.
My setup is on a raspberry pi 1 model B 256MB RAM.
In the web interface it shows that resource consumption is low. ~5% for both CPU and RAM.
I have investigated the log but I do not seem to find what is wrong. (I saw a lot of posts where there were 2 DHCP servers. I hope it is not the case.)
Expected Behaviour:
Pihole should be giving out IP addresses to the devices connected.
Actual Behaviour:
It seems to not be working. On iphone I get some gibberish 169.some other things but not the IP I am expecting. On windows machines it seems to get some IPv6 but I do not have that option enabled.
If I manually make address to a known one, internet works and everything is fine.
Debug Token:
https://tricorder.pi-hole.net/JH1UnGpn/
Your debug log shows Pi-hole's DHCP server to be operational:
*** [ DIAGNOSING ]: Discovering active DHCP servers (takes 10 seconds)
Scanning all your interfaces for DHCP servers
* Received 300 bytes from eth0:192.168.8.103
Offered IP address: 192.168.8.154
Server IP address: 192.168.8.103
Relay-agent IP address: N/A
BOOTP server: (empty)
BOOTP file: (empty)
DHCP options:
Message type: DHCPOFFER (2)
server-identifier: 192.168.8.103
lease-time: 86400 ( 1d )
renewal-time: 43200 ( 12h )
rebinding-time: 75600 ( 21h )
netmask: 255.255.255.0
broadcast: 192.168.8.255
dns-server: 192.168.8.103
domain-name: "lan"
router: 192.168.8.1
--- end of options ---
By chance, your debug log also contains the start of a DHCP negotiation with a client potentially at 192.168.8.154.
Note that DHCP negotiation is initiated by broadcasts, which are limited to the network link that a machine is connected to.
If your network would be split into several such links (e.g. by another router, VLANS, or layer-3 switches), then only clients connected to the same link as your Pi-hole host machine will be able to negotiate a DHCP lease with Pi-hole's DHCP server.
Your debug log also shows that your network has local IPv6 connectivity.
Thus, your router may advertise its own link-local IPv6 address as DNS resolver, allowing IPv6-capable clients to by-pass Pi-hole.
Besides your DHCP issues, you may want to verify whether clients would use your router's IPv6 for DNS, e.g. by running ipconfig /all on a Windows machine and checking the DNS server section of its output.
Wow. Thank you for the fast reply 
I will investigate the possibility of being in a different VLAN. This might be because I am using a wire to control DHCP to Wireless and I saw in the configuration panel of the router that they might be different.
Also I have read over on other posts about the firewall settings. This will be also on the list of checks to do.
In the meanwhile I am battling a driver issue for my wireless adapter for the first revision of raspberry pi (seems the site where it was previously stored is gone).
Thank you!
I will let you know my progress as soon as I will have some