Per-client blocking example

In this example, we describe how to set up a blocking rule for three specific clients. All remaining (and newly added) clients in the network are "unmanaged", i.e., they use Pi-hole as usual. The examples shown here are built upon each other, i.e., example 5 might make no sense without the context of example 3.

Don't forget to run

pihole restartdns reload-lists

after your database modifications to have FTL flush its internal domain-blocking cache (separate from the DNS cache).

Prerequisites

1. Add three groups.

   The Default group has a special meaning and cannot be deleted. All domains, clients, and adlists without a specific group assignment are automatically managed through this group. Disabling this group will disable Pi-hole blocking for all unmanaged devices.

   

   Raw database instructions

   INSERT INTO "group" (id, name) VALUES (1, 'Group 1');
   INSERT INTO "group" (id, name) VALUES (2, 'Group 2');
   INSERT INTO "group" (id, name) VALUES (3, 'Group 3');
   

2. Add three clients.

   Add three clients at your will, their IP addresses might differ from the ones in this example.

   

   Raw database instructions

   INSERT INTO client (id, ip) VALUES (1, '192.168.0.101');
   INSERT INTO client (id, ip) VALUES (2, '192.168.0.102');
   INSERT INTO client (id, ip) VALUES (3, '192.168.0.103');
   

3. Link the clients to the created groups.

   

   Raw database instructions

   INSERT INTO client_by_group (client_id, group_id) VALUES (1, 1);
   INSERT INTO client_by_group (client_id, group_id) VALUES (2, 2);
   INSERT INTO client_by_group (client_id, group_id) VALUES (3, 3);
   

Example 1: Exclude from blocking

Task: Exclude client 1 from Pi-hole's blocking by removing client 1 from the Default group.

Raw database instructions

DELETE FROM client_by_group WHERE client_id = 1 AND group_id = 0;

Result

Client	Group membership	Domain	Blocked
all other	Default	doubleclick.net	Yes
192.168.0.101	Group 1	doubleclick.net	No
192.168.0.102	Group 2 + Default	doubleclick.net	Yes
192.168.0.103	Group 3 + Default	doubleclick.net	Yes

All three clients got automatically assigned to the default (Default) group when they were added. The default group includes all adlists and list domains (if not already changed by the user). When we remove the default group for client 192.168.0.101, we effectively remove all associations to any adlists and domains. This leaves this client completely unblocked.

Example 2: Blocklist management

Task: Assign adlist with ID 1 to group 1 (in addition to the default assignment to group 0). This results in client 192.168.0.101 using only this adlist (we removed the default association in the last step).

Raw database instructions

INSERT INTO adlist_by_group (adlist_id, group_id) VALUES (1,1);

Result

Client	Group membership	Domain	Blocked
all other	Default	doubleclick.net	Yes
192.168.0.101	Group 1	doubleclick.net	Yes
192.168.0.102	Group 2 + Default	doubleclick.net	Yes
192.168.0.103	Group 3 + Default	doubleclick.net	Yes

192.168.0.101 gets doubleclick.net blocked as it uses an adlist including this domain. All other clients stay unchanged.

Example 3: Blacklisting

Task: Add a single domain that should be blacklisted only for group 1 (client 192.168.0.101).

Step 1

Add the domain to be blocked

Raw database instructions

INSERT INTO domainlist (type, domain, comment) VALUES (1, 'blacklisted.com', 'Blacklisted for members of group 1');

Result

Client	Group membership	Domain	Blocked
all other	Default	blacklisted.com	Yes
192.168.0.101	Group 1	blacklisted.com	No
192.168.0.102	Group 2 + Default	blacklisted.com	Yes
192.168.0.103	Group 3 + Default	blacklisted.com	Yes

Note that Pi-hole is not blocking this domain for client 192.168.0.101 as we removed the default assignment through group 0 above. All remaining clients are linked through the Default group to this domain and see it as being blocked.

Step 2

Assign this domain to group 1

Raw database instructions

INSERT INTO domainlist_by_group (domainlist_id, group_id) VALUES (1, 1);

(the domainlist_id might be different for you, check with SELECT last_insert_rowid(); after step 1)

Result

Client	Group membership	Domain	Blocked
all other	Default	blacklisted.com	Yes
192.168.0.101	Group 1	blacklisted.com	Yes
192.168.0.102	Group 2 + Default	blacklisted.com	Yes
192.168.0.103	Group 3 + Default	blacklisted.com	Yes

All clients see this domain as being blocked: Client 1 due to a direct assignment through group 1, all remaining clients through the default group 0 (unchanged).

Step 3

Remove default assignment to all clients not belonging to a group

Raw database instructions

DELETE FROM domainlist_by_group WHERE domainlist_id = 1 AND group_id = 0;

(the domainlist_id might be different for you, see above)

Result

Client	Group membership	Domain	Blocked
all other	Default	blacklisted.com	No
192.168.0.101	Group 1	blacklisted.com	Yes
192.168.0.102	Group 2 + Default	blacklisted.com	No
192.168.0.103	Group 3 + Default	blacklisted.com	No

While client 1 keeps its explicit assignment through group 1, the remaining clients lost their unassignments when we removed group 0 from the assignment.

Example 4: Whitelisting

Task: Add a single domain that should be whitelisted only for group 2 (client 192.168.0.102).

Step 1

Add the domain to be whitelisted

Raw database instructions

INSERT INTO domainlist (type, domain, comment) VALUES (0, 'doubleclick.net', 'Whitelisted for members of group 2');

Result

Client	Group membership	Domain	Blocked
all other	Default	doubleclick.net	No
192.168.0.101	Group 1	doubleclick.net	Yes
192.168.0.102	Group 2 + Default	doubleclick.net	No
192.168.0.103	Group 3 + Default	doubleclick.net	No

Client 192.168.0.101 is not whitelisting this domain as we removed the default assignment through group 0 above. All remaining clients are linked through the default group to this domain and see it as being whitelisted. Note that this is completely analog to step 1 of example 3.

Step 2

Remove default group assignment

Raw database instructions

DELETE FROM domainlist_by_group WHERE domainlist_id = 2 AND group_id = 0;

Result

Client	Group membership	Domain	Blocked
all other	Default	doubleclick.net	Yes
192.168.0.101	Group 1	doubleclick.net	Yes
192.168.0.102	Group 2 + Default	doubleclick.net	Yes
192.168.0.103	Group 3 + Default	doubleclick.net	Yes

Requests from all clients are blocked as the new whitelist entry is not associated with any group and, hence, is not used by any client.

Step 3

Assign this domain to group 2

Raw database instructions

INSERT INTO domainlist_by_group (domainlist_id, group_id) VALUES (2, 2);

(the domainlist_id might be different for you, check with SELECT last_insert_rowid(); after step 1)

Result

Client	Group membership	Domain	Blocked
all other	Default	doubleclick.net	Yes
192.168.0.101	Group 1	doubleclick.net	Yes
192.168.0.102	Group 2 + Default	doubleclick.net	No
192.168.0.103	Group 3 + Default	doubleclick.net	Yes

Client 2 got the whitelist entry explicitly assigned to. Accordingly, client 2 does not get the domain blocked whereas all remaining clients still see this domain as blocked.

---

Last update: July 30, 2022