Editing the Whitelist

Combine Azure uses Squid Cache OpenSSL proxy to achieve airgapping.

To edit the whitelist, you can follow these steps:

1. Connect to the Combine-Proxy virtual machine

Connecting to the proxy virtual machine depends on your Combine configuration. If you are unable to do this please reach out to a Combine Team member.

2. Edit the allowed file

Once you're in the machine, you can:

sudo -s
cd /etc/squid
vi allowed

Edit the file as you please. Things to note:

• Comments are allowed, you can use # to add a comment
• only root domains, i.e. google.com is allowed, google.com/123 is NOT

3. Restart the squid service

You can restart the service (still as root) with:

systemctl restart squid
systemctl status squid

The status should show similar to:

● squid.service - Squid caching proxy
   Loaded: loaded (/usr/lib/systemd/system/squid.service; enabled; vendor preset: disabled)
   Active: active (running) since Tue 2026-01-27 00:00:00 UTC; 6min ago # 👈 the servic is active
  Process: 7862 ExecStop=/usr/sbin/squid -k shutdown -f $SQUID_CONF (code=exited, status=0/SUCCESS)
  Process: 7871 ExecStart=/usr/sbin/squid $SQUID_OPTS -f $SQUID_CONF (code=exited, status=0/SUCCESS)
  Process: 7865 ExecStartPre=/usr/libexec/squid/cache_swap.sh (code=exited, status=0/SUCCESS)
 Main PID: 7874 (squid)
   CGroup: /system.slice/squid.service
           ├─7874 /usr/sbin/squid -f /etc/squid/squid.conf
           └─7876 (squid-1) -f /etc/squid/squid.conf

Jan 01 00:00:00 Combine-Proxy systemd[1]: Stopped Squid caching proxy.
Jan 01 00:00:00 Combine-Proxy systemd[1]: Starting Squid caching proxy...
Jan 01 00:00:00 Combine-Proxy squid[7874]: Squid Parent: will start 1 kids
Jan 01 00:00:00 Combine-Proxy squid[7874]: Squid Parent: (squid-1) process 7876 started
Jan 01 00:00:00 Combine-Proxy systemd[1]: Started Squid caching proxy.