Installing an External Smart Proxy Server 3.5

1. Preparing your Environment for Installation

1.1. System Requirements

The following requirements apply to the networked base operating system:

x86_64 architecture
4-core 2.0 GHz CPU at a minimum
Administrative user (root) access
Full forward and reverse DNS resolution using a fully-qualified domain name

Foreman only supports UTF-8 encoding. If your territory is USA and your language is English, set en_US.utf-8 as the system-wide locale settings. For more information about configuring system locale in Enterprise Linux, see Configuring System Locale guide.

Foreman server and Smart Proxy server do not support shortnames in the hostnames. When using custom certificates, the Common Name (CN) of the custom certificate must be a fully qualified domain name (FQDN) instead of a shortname. This does not apply to the clients of a Foreman.

Before you install Smart Proxy server, ensure that your environment meets the requirements for installation.

Warning

The version of Smart Proxy must match with the version of Foreman installed. It should not be different. For example, the Smart Proxy version 3.5 cannot be registered with the Foreman version 3.4.

Smart Proxy server must be installed on a freshly provisioned system that serves no other function except to run Smart Proxy server. The freshly provisioned system must not have the following users provided by external identity providers to avoid conflicts with the local users that Smart Proxy server creates:

apache
foreman-proxy
postgres
puppet
redis

SELinux Mode

SELinux must be enabled, either in enforcing or permissive mode. Installation with disabled SELinux is not supported.

FIPS mode

You can install Smart Proxy on a Enterprise Linux system that is operating in FIPS mode. You cannot enable FIPS mode after the installation of Smart Proxy. Red Hat Enterprise Linux clones are not being actively tested in FIPS mode. If you require FIPS, consider using Red Hat Enterprise Linux. For more information, see Switching RHEL to FIPS mode in Red Hat Enterprise Linux 8 Security hardening.

Note	Foreman supports DEFAULT and FIPS crypto-policies. The FUTURE crypto-policy is not supported for Foreman and Smart Proxy installations.

1.2. Supported Operating Systems

You can install the operating system from a disc, local ISO image, or kickstart.

The following operating systems are supported by the installer, have packages, and are tested for deploying Foreman:

Table 1. Operating Systems supported by foreman-installer
Operating System	Architecture	Notes
Enterprise Linux 8	x86_64 only	EPEL is not supported.

Before you install Foreman, apply all operating system updates if possible.

Install Smart Proxy server on a freshly provisioned system.

1.3. Ports and Firewalls Requirements

For the components of Foreman architecture to communicate, ensure that the required network ports are open and free on the base operating system. You must also ensure that the required network ports are open on any network-based firewalls.

The installation of a Smart Proxy server fails if the ports between Foreman server and Smart Proxy server are not open before installation starts.

Use this information to configure any network-based firewalls. Note that some cloud solutions must be specifically configured to allow communications between machines because they isolate machines similarly to network-based firewalls. If you use an application-based firewall, ensure that the application-based firewall permits all applications that are listed in the tables and known to your firewall. If possible, disable the application checking and allow open port communication based on the protocol.

Integrated Smart Proxy

Foreman server has an integrated Smart Proxy and any host that is directly connected to Foreman server is a Client of Foreman in the context of this section. This includes the base operating system on which Smart Proxy server is running.

Clients of Smart Proxy

Hosts which are clients of Smart Proxies, other than Foreman’s integrated Smart Proxy, do not need access to Foreman server. For more information on Foreman Topology, see Smart Proxy Networking in Planning for Foreman.

Required ports can change based on your configuration.

The following tables indicate the destination port and the direction of network traffic:

Table 2. Smart Proxy incoming traffic
Destination Port	Protocol	Service	Source	Required For	Description
53	TCP and UDP	DNS	DNS Servers and clients	Name resolution	DNS (optional)
67	UDP	DHCP	Client	Dynamic IP	DHCP (optional)
69	UDP	TFTP	Client	TFTP Server (optional)
8000	TCP	HTTP	Client	Provisioning templates	Template retrieval for client installers, iPXE or UEFI HTTP Boot
8000	TCP	HTTP	Client	PXE Boot	Installation
8140	TCP	HTTPS	Client	Puppet agent	Client updates (optional)
8443	TCP	HTTPS	Foreman	Smart Proxy API	Smart Proxy functionality
8443	TCP	HTTPS	Client	Register Endpoint	Client registration with an external Smart Proxy server
8443	TCP	HTTPS	Client	OpenSCAP	Configure Client (if the OpenSCAP plugin is installed)
8443	TCP	HTTPS	Discovered Node	Discovery	Host discovery and provisioning (if the discovery plugin is installed)

Any managed host that is directly connected to Foreman server is a client in this context because it is a client of the integrated Smart Proxy. This includes the base operating system on which a Smart Proxy server is running.

A DHCP Smart Proxy performs ICMP ping and TCP echo connection attempts to hosts in subnets with DHCP IPAM set to find out if an IP address considered for use is free. This behavior can be turned off using foreman-installer --foreman-proxy-dhcp-ping-free-ip=false.

Table 3. Smart Proxy outgoing traffic
Destination Port	Protocol	Service	Destination	Required For	Description
	ICMP	ping	Client	DHCP	Free IP checking (optional)
7	TCP	echo	Client	DHCP	Free IP checking (optional)
22	TCP	SSH	Target host	Remote execution	Run jobs
53	TCP and UDP	DNS	DNS Servers on the Internet	DNS Server	Resolve DNS records (optional)
53	TCP and UDP	DNS	DNS Server	Smart Proxy DNS	Validation of DNS conflicts (optional)
68	UDP	DHCP	Client	Dynamic IP	DHCP (optional)
443	TCP	HTTPS	Foreman	Smart Proxy	Smart Proxy Configuration management Template retrieval OpenSCAP Remote Execution result upload
443	TCP	HTTPS	Infoblox DHCP Server	DHCP management	When using Infoblox for DHCP, management of the DHCP leases (optional)
623			Client	Power management	BMC On/Off/Cycle/Status
7911	TCP	DHCP, OMAPI	DHCP Server	DHCP	The DHCP target is configured using `--foreman-proxy-dhcp-server` and defaults to localhost ISC and `remote_isc` use a configurable port that defaults to 7911 and uses OMAPI
8443	TCP	HTTPS	Client	Discovery	Smart Proxy sends reboot command to the discovered host (optional)

Note	ICMP to Port 7 UDP and TCP must not be rejected, but can be dropped. The DHCP Smart Proxy sends an ECHO REQUEST to the Client network to verify that an IP address is free. Any response will prevent IP addresses being allocated.

1.4. Enabling Connections from Smart Proxy Server to Foreman server

On Foreman server, you must enable the incoming connection from Smart Proxy server to Foreman server and make this rule persistent across reboots.

Prerequisites

Ensure that the firewall rules on Foreman server are configured to enable connections for client to Foreman communication, because Smart Proxy server is a client of Foreman server. For more information, see Enabling Connections from a Client to Foreman server in Installing Foreman 3.5 Server on RHEL/CentOS.

If you do not use firewall-cmd to configure the Linux firewall, implement using the command of your choice.

Procedure

On Foreman server, enter the following command to open the port for Smart Proxy to Foreman communication:
```
# firewall-cmd --add-port="5646/tcp"
```
Make the changes persistent:
```
# firewall-cmd --runtime-to-permanent
```

1.5. Enabling Connections from Foreman server and Clients to a Smart Proxy Server

On the base operating system on which you want to install Smart Proxy, you must enable incoming connections from Foreman server and clients to Smart Proxy server and make these rules persistent across reboots.

If you do not use firewall-cmd to configure the Linux firewall, implement using the command of your choice.

Procedure

On the base operating system on which you want to install Smart Proxy, enter the following command to open the ports for Foreman server and clients communication to Smart Proxy server:
```
# firewall-cmd \
--add-port="53/udp" --add-port="53/tcp" \
--add-port="67/udp" \
--add-port="69/udp" \
--add-port="8140/tcp" \
--add-port="8443/tcp" \
```
Make the changes persistent:
```
# firewall-cmd --runtime-to-permanent
```

Verification

Enter the following command:
```
# firewall-cmd --list-all
```

For more information, see Using and Configuring firewalld in Red Hat Enterprise Linux 8 Securing networks.

2. Installing Smart Proxy Server

Before you install Smart Proxy server, you must ensure that your environment meets the requirements for installation. For more information, see Preparing your Environment for Installation.

2.1. Configuring Repositories

Use these procedures to enable the repositories required to install Smart Proxy server.

Choose from the following list which operating system and version you are installing on:

CentOS Stream 8
Red Hat Enterprise Linux 8

2.1.1. CentOS Stream 8

Clear any metadata:
```
# dnf clean all
```

Install the foreman-release.rpm package:

# dnf install https://yum.theforeman.org/releases/3.5/el8/x86_64/foreman-release.rpm

Install the puppet7-release-el-8.noarch.rpm package:

# dnf install https://yum.puppet.com/puppet7-release-el-8.noarch.rpm

Enable the DNF modules:
```
# dnf module enable foreman:el8
```

2.1.2. Red Hat Enterprise Linux 8

Disable all repositories:

# subscription-manager repos --disable "*"

Enable the following repositories:

# subscription-manager repos --enable=rhel-8-for-x86_64-baseos-rpms \
--enable=rhel-8-for-x86_64-appstream-rpms

Clear any metadata:
```
# dnf clean all
```

Install the foreman-release.rpm package:

# dnf install https://yum.theforeman.org/releases/3.5/el8/x86_64/foreman-release.rpm

Install the puppet7-release-el-8.noarch.rpm package:

# dnf install https://yum.puppet.com/puppet7-release-el-8.noarch.rpm

Enable the DNF modules:

# dnf module enable foreman:el8

Note	If there is any warning about conflicts with Ruby or PostgreSQL while enabling `foreman:el8` module, see Troubleshooting DNF modules. For more information about modules and lifecycle streams on Red Hat Enterprise Linux 8, see Red Hat Enterprise Linux Application Streams Life Cycle.

2.2. Installing Smart Proxy Server Packages

Before installing Smart Proxy server packages, you must update all packages that are installed on the base operating system.

Procedure

To install Smart Proxy server, complete the following steps:

Update all packages:
```
# dnf update
```
Install foreman-installer:
```
# dnf install foreman-installer
```

2.3. Installing Smart Proxy Server

Procedure

To install an external Smart Proxy, enter the following command:

foreman-installer \
  --no-enable-foreman \
  --no-enable-foreman-cli \
  --enable-puppet \
  --puppet-server-ca=false \
  --puppet-server-foreman-url=https://foreman.example.com \
  --enable-foreman-proxy \
  --foreman-proxy-puppetca=false \
  --foreman-proxy-tftp=false \
  --foreman-proxy-foreman-base-url=https://foreman.example.com \
  --foreman-proxy-trusted-hosts=foreman.example.com \
  --foreman-proxy-oauth-consumer-key=oAuth_Consumer_Key \
  --foreman-proxy-oauth-consumer-secret=oAuth_Consumer_Secret

2.4. Synchronizing the System Clock With chronyd

To minimize the effects of time drift, you must synchronize the system clock on the base operating system on which you want to install Smart Proxy server with Network Time Protocol (NTP) servers. If the base operating system clock is configured incorrectly, certificate verification might fail.

For more information about the chrony suite, see Using the Chrony suite to configure NTP in Red Hat Enterprise Linux 8 Configuring basic system settings.

Procedure

Install the chrony package:
```
# dnf install chrony
```
Start and enable the chronyd service:
```
# systemctl enable --now chronyd
```

2.5. Assigning the Correct Organization and Location to Smart Proxy Server in the Foreman web UI

After installing Smart Proxy server packages, if there is more than one organization or location, you must assign the correct organization and location to Smart Proxy to make Smart Proxy visible in the Foreman web UI.

Procedure

Log into the Foreman web UI.
From the Organization list in the upper-left of the screen, select Any Organization.
From the Location list in the upper-left of the screen, select Any Location.
In the Foreman web UI, navigate to Hosts > All Hosts and select Smart Proxy server.
From the Select Actions list, select Assign Organization.
From the Organization list, select the organization where you want to assign this Smart Proxy.
Click Fix Organization on Mismatch.
Click Submit.
Select Smart Proxy server. From the Select Actions list, select Assign Location.
From the Location list, select the location where you want to assign this Smart Proxy.
Click Fix Location on Mismatch.
Click Submit.
In the Foreman web UI, navigate to Administer > Organizations and click the organization to which you have assigned Smart Proxy.
Click Smart Proxies tab and ensure that Smart Proxy server is listed under the Selected items list, then click Submit.
In the Foreman web UI, navigate to Administer > Locations and click the location to which you have assigned Smart Proxy.
Click Smart Proxies tab and ensure that Smart Proxy server is listed under the Selected items list, then click Submit.

Verification

Optionally, you can verify if Smart Proxy server is correctly listed in the Foreman web UI.

Select the organization from the Organization list.
Select the location from the Location list.
In the Foreman web UI, navigate to Hosts > All Hosts.
In the Foreman web UI, navigate to Infrastructure > Smart Proxies.

3. Performing Additional Configuration on Smart Proxy Server

Use this chapter to configure additional settings on your Smart Proxy server.

3.1. Configuring Smart Proxy for Host Registration and Provisioning

Use this procedure to configure Smart Proxy so that you can register and provision hosts using your Smart Proxy server instead of your Foreman server.

Procedure

Enable the Registration and Templates features on your Smart Proxy server and set the template URL:

# foreman-installer --no-enable-foreman --no-enable-foreman-plugin-puppet --no-enable-foreman-cli --no-enable-foreman-cli-puppet \
--foreman-proxy-registration true \
--foreman-proxy-templates true \
--foreman-proxy-template-url "http://smartproxy.example.com:8000"

On your Smart Proxy server, open the corresponding ports:

# firewall-cmd --permanent --zone=public --add-port=8000/tcp

On your Smart Proxy server, reload the firewall configuration:
```
# firewall-cmd --reload
```
On Foreman server, add the Smart Proxy to the list of trusted proxies.

This is required for Foreman to recognize hosts' IP addresses forwarded over the X-Forwarded-For HTTP header set by Smart Proxy. For security reasons, Foreman recognizes this HTTP header only from localhost by default. You can enter trusted proxies as valid IPv4 or IPv6 addresses of Smart Proxies, or network ranges.

Warning
Do not use a network range that is too wide, because that poses a potential security risk.

Enter the following command. Note that the command overwrites the list that is currently stored in Foreman. Therefore, if you have set any trusted proxies previously, you must include them in the command as well:
```
# foreman-installer \
--foreman-trusted-proxies "127.0.0.1/8" \
--foreman-trusted-proxies "::1" \
--foreman-trusted-proxies "My_IP_address" \
--foreman-trusted-proxies "My_IP_range"
```
The localhost entries are required, do not omit them.

Verification

List the current trusted proxies using the full help of Foreman installer:
```
# foreman-installer --full-help | grep -A 2 "trusted-proxies"
```
The current listing contains all trusted proxies you require.

3.2. Enabling OpenSCAP on Smart Proxy Servers

On Foreman server and the integrated Smart Proxy of your Foreman server, OpenSCAP is enabled by default. To use the OpenSCAP plug-in and content on external Smart Proxies, you must enable OpenSCAP on each Smart Proxy.

Procedure

To enable OpenSCAP, enter the following command:

# foreman-installer --no-enable-foreman --no-enable-foreman-plugin-puppet --no-enable-foreman-cli --no-enable-foreman-cli-puppet \
--enable-foreman-proxy-plugin-openscap \
--foreman-proxy-plugin-openscap-puppet-module true

3.3. Enabling Power Management on Managed Hosts

To perform power management tasks on managed hosts using the intelligent platform management interface (IPMI) or a similar protocol, you must enable the baseboard management controller (BMC) module on Smart Proxy server.

Prerequisites

All managed hosts must have a network interface of BMC type. Smart Proxy server uses this NIC to pass the appropriate credentials to the host. For more information, see Adding a Baseboard Management Controller (BMC) Interface in Managing Hosts.

Procedure

To enable BMC, enter the following command:

# foreman-installer --no-enable-foreman --no-enable-foreman-plugin-puppet --no-enable-foreman-cli --no-enable-foreman-cli-puppet \
--foreman-proxy-bmc "true" \
--foreman-proxy-bmc-default-provider "freeipmi"

3.4. Configuring DNS, DHCP, and TFTP on Smart Proxy server

To configure the DNS, DHCP, and TFTP services on Smart Proxy server, use the foreman-installer command with the options appropriate for your environment. To view a complete list of configurable options, enter the foreman-installer --help command.

Any changes to the settings require entering the foreman-installer command again. You can enter the command multiple times and each time it updates all configuration files with the changed values.

To use external DNS, DHCP, and TFTP services instead, see Configuring Smart Proxy server with External Services.

Adding Multihomed DHCP details

If you want to use Multihomed DHCP, you must inform the installer.

Prerequisites

You must have the correct network name (dns-interface) for the DNS server.
You must have the correct interface name (dhcp-interface) for the DHCP server.
Contact your network administrator to ensure that you have the correct settings.

Procedure

Enter the foreman-installer command with the options appropriate for your environment. The following example shows configuring full provisioning services:

# foreman-installer --no-enable-foreman --no-enable-foreman-plugin-puppet --no-enable-foreman-cli --no-enable-foreman-cli-puppet \
--foreman-proxy-dns true \
--foreman-proxy-dns-managed true \
--foreman-proxy-dns-interface eth0 \
--foreman-proxy-dns-zone example.com \
--foreman-proxy-dns-reverse 2.0.192.in-addr.arpa \
--foreman-proxy-dhcp true \
--foreman-proxy-dhcp-managed true \
--foreman-proxy-dhcp-interface eth0 \
--foreman-proxy-dhcp-additional-interfaces eth1 \
--foreman-proxy-dhcp-additional-interfaces eth2 \
--foreman-proxy-dhcp-range "192.0.2.100 192.0.2.150" \
--foreman-proxy-dhcp-gateway 192.0.2.1 \
--foreman-proxy-dhcp-nameservers 192.0.2.2 \
--foreman-proxy-tftp true \
--foreman-proxy-tftp-managed true \
--foreman-proxy-tftp-servername 192.0.2.3

For more information about configuring DHCP, DNS, and TFTP services, see Configuring Network Services in Provisioning Hosts.

4. Configuring Smart Proxy server with External Services

If you do not want to configure the DNS, DHCP, and TFTP services on Smart Proxy server, use this section to configure your Smart Proxy server to work with external DNS, DHCP and TFTP services.

4.1. Configuring Smart Proxy server with External DNS

You can configure Smart Proxy server with external DNS. Smart Proxy server uses the nsupdate utility to update DNS records on the remote server.

To make any changes persistent, you must enter the foreman-installer command with the options appropriate for your environment.

Prerequisites

You must have a configured external DNS server.
This guide assumes you have an existing installation.

Procedure

Copy the /etc/rndc.key file from the external DNS server to Smart Proxy server:
```
# scp root@dns.example.com:/etc/rndc.key /etc/foreman-proxy/rndc.key
```

Configure the ownership, permissions, and SELinux context:

# restorecon -v /etc/foreman-proxy/rndc.key
# chown -v root:foreman-proxy /etc/foreman-proxy/rndc.key
# chmod -v 640 /etc/foreman-proxy/rndc.key

To test the nsupdate utility, add a host remotely:

# echo -e "server DNS_IP_Address\n \
update add aaa.example.com 3600 IN A Host_IP_Address\n \
send\n" | nsupdate -k /etc/foreman-proxy/rndc.key
# nslookup aaa.example.com DNS_IP_Address
# echo -e "server DNS_IP_Address\n \
update delete aaa.example.com 3600 IN A Host_IP_Address\n \
send\n" | nsupdate -k /etc/foreman-proxy/rndc.key

Enter the foreman-installer command to make the following persistent changes to the /etc/foreman-proxy/settings.d/dns.yml file:

# foreman-installer --foreman-proxy-dns=true \
--foreman-proxy-dns-managed=false \
--foreman-proxy-dns-provider=nsupdate \
--foreman-proxy-dns-server="DNS_IP_Address" \
--foreman-proxy-keyfile=/etc/foreman-proxy/rndc.key

In the Foreman web UI, navigate to Infrastructure > Smart Proxies.
Locate the Smart Proxy server and select Refresh from the list in the Actions column.
Associate the DNS service with the appropriate subnets and domain.

4.2. Configuring Smart Proxy server with External DHCP

To configure Smart Proxy server with external DHCP, you must complete the following procedures:

Configuring an External DHCP Server to Use with Smart Proxy server
Configuring Foreman server with an External DHCP Server

4.2.1. Configuring an External DHCP Server to Use with Smart Proxy server

To configure an external DHCP server running Enterprise Linux to use with Smart Proxy server, you must install the ISC DHCP Service and Berkeley Internet Name Domain (BIND) utilities packages. You must also share the DHCP configuration and lease files with Smart Proxy server. The example in this procedure uses the distributed Network File System (NFS) protocol to share the DHCP configuration and lease files.

Note

If you use dnsmasq as an external DHCP server, enable the dhcp-no-override setting. This is required because Foreman creates configuration files on the TFTP server under the grub2/ subdirectory. If the dhcp-no-override setting is disabled, clients fetch the bootloader and its configuration from the root directory, which might cause an error.

If you do not use firewall-cmd to configure the Linux firewall, implement using the command of your choice.

Procedure

On your Enterprise Linux host, install the ISC DHCP Service and Berkeley Internet Name Domain (BIND) utilities packages:
```
# dnf install dhcp-server bind-utils
```
Generate a security token:
```
# tsig-keygen -a hmac-md5 omapi_key
```

Edit the dhcpd configuration file for all subnets and add the key generated by tsig-keygen. The following is an example:

# cat /etc/dhcp/dhcpd.conf
default-lease-time 604800;
max-lease-time 2592000;
log-facility local7;

subnet 192.168.38.0 netmask 255.255.255.0 {
	range 192.168.38.10 192.168.38.100;
	option routers 192.168.38.1;
	option subnet-mask 255.255.255.0;
	option domain-search "virtual.lan";
	option domain-name "virtual.lan";
	option domain-name-servers 8.8.8.8;
}

omapi-port 7911;
key omapi_key {
	algorithm hmac-md5;
	secret "My_Secret";
};
omapi-key omapi_key;

Note that the option routers value is the IP address of your Foreman server or Smart Proxy server that you want to use with an external DHCP service.

On Foreman server, define each subnet. Do not set DHCP Smart Proxy for the defined Subnet yet.

To prevent conflicts, set up the lease and reservation ranges separately. For example, if the lease range is 192.168.38.10 to 192.168.38.100, in the Foreman web UI define the reservation range as 192.168.38.101 to 192.168.38.250.

Configure the firewall for external access to the DHCP server:

# firewall-cmd --add-service dhcp \
&& firewall-cmd --runtime-to-permanent

On Foreman server, determine the UID and GID of the foreman user:
```
# id -u foreman
993
# id -g foreman
990
```
On the DHCP server, create the foreman user and group with the same IDs as determined in a previous step:
```
# groupadd -g 990 foreman
# useradd -u 993 -g 990 -s /sbin/nologin foreman
```

To ensure that the configuration files are accessible, restore the read and execute flags:

# chmod o+rx /etc/dhcp/
# chmod o+r /etc/dhcp/dhcpd.conf
# chattr +i /etc/dhcp/ /etc/dhcp/dhcpd.conf

Enable and start the DHCP service:
```
# systemctl enable --now dhcpd
```

Export the DHCP configuration and lease files using NFS:

# dnf install nfs-utils
# systemctl enable --now nfs-server

Create directories for the DHCP configuration and lease files that you want to export using NFS:
```
# mkdir -p /exports/var/lib/dhcpd /exports/etc/dhcp
```

To create mount points for the created directories, add the following line to the /etc/fstab file:

/var/lib/dhcpd /exports/var/lib/dhcpd none bind,auto 0 0
/etc/dhcp /exports/etc/dhcp none bind,auto 0 0

Mount the file systems in /etc/fstab:
```
# mount -a
```

Ensure the following lines are present in /etc/exports:

/exports 192.168.38.1(rw,async,no_root_squash,fsid=0,no_subtree_check)

/exports/etc/dhcp 192.168.38.1(ro,async,no_root_squash,no_subtree_check,nohide)

/exports/var/lib/dhcpd 192.168.38.1(ro,async,no_root_squash,no_subtree_check,nohide)

Note that the IP address that you enter is the Foreman or Smart Proxy IP address that you want to use with an external DHCP service.

Reload the NFS server:
```
# exportfs -rva
```

Configure the firewall for DHCP omapi port 7911:

# firewall-cmd --add-port=7911/tcp
# firewall-cmd --runtime-to-permanent

Optional: Configure the firewall for external access to NFS. Clients are configured using NFSv3.

# firewall-cmd --zone public --add-service mountd \
&& firewall-cmd --zone public --add-service rpc-bind \
&& firewall-cmd --zone public --add-service nfs \
&& firewall-cmd --runtime-to-permanent

4.2.2. Configuring Foreman server with an External DHCP Server

You can configure Smart Proxy server with an external DHCP server.

Prerequisite

Ensure that you have configured an external DHCP server and that you have shared the DHCP configuration and lease files with Smart Proxy server. For more information, see Configuring an External DHCP Server to Use with Smart Proxy server.

Procedure

Install the nfs-utils package:
```
# dnf install nfs-utils
```

Create the DHCP directories for NFS:

# mkdir -p /mnt/nfs/etc/dhcp /mnt/nfs/var/lib/dhcpd

Change the file owner:
```
# chown -R foreman-proxy /mnt/nfs
```
Verify communication with the NFS server and the Remote Procedure Call (RPC) communication paths:
```
# showmount -e DHCP_Server_FQDN
# rpcinfo -p DHCP_Server_FQDN
```

Add the following lines to the /etc/fstab file:

DHCP_Server_FQDN:/exports/etc/dhcp /mnt/nfs/etc/dhcp nfs
ro,vers=3,auto,nosharecache,context="system_u:object_r:dhcp_etc_t:s0" 0 0

DHCP_Server_FQDN:/exports/var/lib/dhcpd /mnt/nfs/var/lib/dhcpd nfs
ro,vers=3,auto,nosharecache,context="system_u:object_r:dhcpd_state_t:s0" 0 0

Mount the file systems on /etc/fstab:
```
# mount -a
```

To verify that the foreman-proxy user can access the files that are shared over the network, display the DHCP configuration and lease files:

# su foreman-proxy -s /bin/bash
bash-4.2$ cat /mnt/nfs/etc/dhcp/dhcpd.conf
bash-4.2$ cat /mnt/nfs/var/lib/dhcpd/dhcpd.leases
bash-4.2$ exit

Enter the foreman-installer command to make the following persistent changes to the /etc/foreman-proxy/settings.d/dhcp.yml file:

# foreman-installer --foreman-proxy-dhcp=true \
--foreman-proxy-dhcp-provider=remote_isc \
--foreman-proxy-plugin-dhcp-remote-isc-dhcp-config /mnt/nfs/etc/dhcp/dhcpd.conf \
--foreman-proxy-plugin-dhcp-remote-isc-dhcp-leases /mnt/nfs/var/lib/dhcpd/dhcpd.leases \
--foreman-proxy-plugin-dhcp-remote-isc-key-name=omapi_key \
--foreman-proxy-plugin-dhcp-remote-isc-key-secret=jNSE5YI3H1A8Oj/tkV4...A2ZOHb6zv315CkNAY7DMYYCj48Umw== \
--foreman-proxy-plugin-dhcp-remote-isc-omapi-port=7911 \
--enable-foreman-proxy-plugin-dhcp-remote-isc \
--foreman-proxy-dhcp-server=DHCP_Server_FQDN

Associate the DHCP service with the appropriate subnets and domain.

4.3. Configuring Smart Proxy server with External TFTP

You can configure Smart Proxy server with external TFTP services.

Procedure

Create the TFTP directory for NFS:
```
# mkdir -p /mnt/nfs/var/lib/tftpboot
```

In the /etc/fstab file, add the following line:

TFTP_Server_IP_Address:/exports/var/lib/tftpboot /mnt/nfs/var/lib/tftpboot nfs rw,vers=3,auto,nosharecache,context="system_u:object_r:tftpdir_rw_t:s0" 0 0

Mount the file systems in /etc/fstab:
```
# mount -a
```
Enter the foreman-installer command to make the following persistent changes to the /etc/foreman-proxy/settings.d/tftp.yml file:
```
# foreman-installer --foreman-proxy-tftp=true \
--foreman-proxy-tftp-root /mnt/nfs/var/lib/tftpboot
```
If the TFTP service is running on a different server than the DHCP service, update the tftp_servername setting with the FQDN or IP address of the server that the TFTP service is running on:
```
# foreman-installer --foreman-proxy-tftp-servername=TFTP_Server_FQDN
```
In the Foreman web UI, navigate to Infrastructure > Smart Proxies.
Locate the Smart Proxy server and select Refresh from the list in the Actions column.
Associate the TFTP service with the appropriate subnets and domain.

4.4. Configuring Smart Proxy server with External IdM DNS

When Foreman server adds a DNS record for a host, it first determines which Smart Proxy is providing DNS for that domain. It then communicates with the Smart Proxy that is configured to provide DNS service for your deployment and adds the record. The hosts are not involved in this process. Therefore, you must install and configure the IdM client on the Foreman or Smart Proxy that is currently configured to provide a DNS service for the domain you want to manage using the IdM server.

Smart Proxy server can be configured to use a Red Hat Identity Management (IdM) server to provide DNS service. For more information about Red Hat Identity Management, see the Linux Domain Identity, Authentication, and Policy Guide.

To configure Smart Proxy server to use a Red Hat Identity Management (IdM) server to provide DNS service, use one of the following procedures:

Configuring Dynamic DNS Update with GSS-TSIG Authentication
Configuring Dynamic DNS Update with TSIG Authentication

To revert to internal DNS service, use the following procedure:

Reverting to Internal DNS Service

Note

You are not required to use Smart Proxy server to manage DNS. When you are using the realm enrollment feature of Foreman, where provisioned hosts are enrolled automatically to IdM, the ipa-client-install script creates DNS records for the client. Configuring Smart Proxy server with external IdM DNS and realm enrollment are mutually exclusive. For more information about configuring realm enrollment, see External Authentication for Provisioned Hosts in Installing Foreman 3.5 Server on RHEL/CentOS.

4.4.1. Configuring Dynamic DNS Update with GSS-TSIG Authentication

You can configure the IdM server to use the generic security service algorithm for secret key transaction (GSS-TSIG) technology defined in RFC3645. To configure the IdM server to use the GSS-TSIG technology, you must install the IdM client on the Smart Proxy server base operating system.

Prerequisites

You must ensure the IdM server is deployed and the host-based firewall is configured correctly.
You must contact the IdM server administrator to ensure that you obtain an account on the IdM server with permissions to create zones on the IdM server.
You should create a backup of the answer file. You can use the backup to restore the answer file to its original state if it becomes corrupted. For more information, see Configuring Foreman server.

Procedure

To configure dynamic DNS update with GSS-TSIG authentication, complete the following steps:

Creating a Kerberos Principal on the IdM Server

Obtain a Kerberos ticket for the account obtained from the IdM administrator:
```
# kinit idm_user
```
Create a new Kerberos principal for Smart Proxy server to use to authenticate on the IdM server.
```
# ipa service-add smartproxy.example.com
```

Installing and Configuring the IdM Client

On the base operating system of either the Foreman or Smart Proxy that is managing the DNS service for your deployment, install the ipa-client package:
```
# dnf install ipa-client
```
Configure the IdM client by running the installation script and following the on-screen prompts:
```
# ipa-client-install
```
Obtain a Kerberos ticket:
```
# kinit admin
```
Remove any preexisting keytab:
```
# rm /etc/foreman-proxy/dns.keytab
```

Obtain the keytab for this system:

# ipa-getkeytab -p smartproxy/foreman.example.com@EXAMPLE.COM \
-s idm1.example.com -k /etc/foreman-proxy/dns.keytab

Note	When adding a keytab to a standby system with the same host name as the original system in service, add the `r` option to prevent generating new credentials and rendering the credentials on the original system invalid.

For the dns.keytab file, set the group and owner to foreman-proxy:

# chown foreman-proxy:foreman-proxy /etc/foreman-proxy/dns.keytab

Optional: To verify that the keytab file is valid, enter the following command:

# kinit -kt /etc/foreman-proxy/dns.keytab \
smartproxy/foreman.example.com@EXAMPLE.COM

Configuring DNS Zones in the IdM web UI

Create and configure the zone that you want to manage:
1. Navigate to Network Services > DNS > DNS Zones.
2. Select Add and enter the zone name. For example, example.com.
3. Click Add and Edit.
4. Click the Settings tab and in the BIND update policy box, add the following to the semi-colon separated list:
  grant smartproxy\047foreman.example.com@EXAMPLE.COM wildcard * ANY;
5. Set Dynamic update to True.
6. Enable Allow PTR sync.
7. Click Save to save the changes.
Create and configure the reverse zone:
1. Navigate to Network Services > DNS > DNS Zones.
2. Click Add.
3. Select Reverse zone IP network and add the network address in CIDR format to enable reverse lookups.
4. Click Add and Edit.
5. Click the Settings tab and in the BIND update policy box, add the following to the semi-colon separated list:
  grant smartproxy\047foreman.example.com@EXAMPLE.COM wildcard * ANY;
6. Set Dynamic update to True.
7. Click Save to save the changes.

Configuring the Foreman or Smart Proxy Server that Manages the DNS Service for the Domain

Use the foreman-installer command to configure the Foreman or Smart Proxy that manages the DNS Service for the domain:

On Foreman, enter the following command:

foreman-installer \
--foreman-proxy-dns=true \
--foreman-proxy-dns-managed=false \
--foreman-proxy-dns-provider=nsupdate_gss \
--foreman-proxy-dns-server="idm1.example.com" \
--foreman-proxy-dns-tsig-principal="smartproxy/foreman.example.com@EXAMPLE.COM" \
--foreman-proxy-dns-tsig-keytab=/etc/foreman-proxy/dns.keytab

On Smart Proxy, enter the following command:

foreman-installer --no-enable-foreman --no-enable-foreman-plugin-puppet --no-enable-foreman-cli --no-enable-foreman-cli-puppet \
--foreman-proxy-dns=true \
--foreman-proxy-dns-managed=false \
--foreman-proxy-dns-provider=nsupdate_gss \
--foreman-proxy-dns-server="idm1.example.com" \
--foreman-proxy-dns-tsig-principal="smartproxy/foreman.example.com@EXAMPLE.COM" \
--foreman-proxy-dns-tsig-keytab=/etc/foreman-proxy/dns.keytab

After you run the foreman-installer command to make any changes to your Smart Proxy configuration, you must update the configuration of each affected Smart Proxy in the Foreman web UI.

Updating the Configuration in the Foreman web UI

In the Foreman web UI, navigate to Infrastructure > Smart Proxies, locate the Smart Proxy server, and from the list in the Actions column, select Refresh.
Configure the domain:
1. In the Foreman web UI, navigate to Infrastructure > Domains and select the domain name.
2. In the Domain tab, ensure DNS Smart Proxy is set to the Smart Proxy where the subnet is connected.
Configure the subnet:
1. In the Foreman web UI, navigate to Infrastructure > Subnets and select the subnet name.
2. In the Subnet tab, set IPAM to None.
3. In the Domains tab, select the domain that you want to manage using the IdM server.
4. In the Smart Proxies tab, ensure Reverse DNS Smart Proxy is set to the Smart Proxy where the subnet is connected.
5. Click Submit to save the changes.

4.4.2. Configuring Dynamic DNS Update with TSIG Authentication

You can configure an IdM server to use the secret key transaction authentication for DNS (TSIG) technology that uses the rndc.key key file for authentication. The TSIG protocol is defined in RFC2845.

Prerequisites

You must ensure the IdM server is deployed and the host-based firewall is configured correctly. For more information, see Port Requirements in the Linux Domain Identity, Authentication, and Policy Guide.
You must obtain root user access on the IdM server.
You must confirm whether Foreman server or Smart Proxy server is configured to provide DNS service for your deployment.
You must configure DNS, DHCP and TFTP services on the base operating system of either the Foreman or Smart Proxy that is managing the DNS service for your deployment.
You must create a backup of the answer file. You can use the backup to restore the answer file to its original state if it becomes corrupted. For more information, see Configuring Foreman server.

Procedure

To configure dynamic DNS update with TSIG authentication, complete the following steps:

Enabling External Updates to the DNS Zone in the IdM Server

On the IdM Server, add the following to the top of the /etc/named.conf file:

########################################################################

include "/etc/rndc.key";
controls  {
inet _IdM_Server_IP_Address_ port 953 allow { _Foreman_IP_Address_; } keys { "rndc-key"; };
};
########################################################################

Reload the named service to make the changes take effect:
```
# systemctl reload named
```
In the IdM web UI, navigate to Network Services > DNS > DNS Zones and click the name of the zone. In the Settings tab, apply the following changes:
1. Add the following in the BIND update policy box:
  grant "rndc-key" zonesub ANY;
2. Set Dynamic update to True.
3. Click Update to save the changes.
Copy the /etc/rndc.key file from the IdM server to the base operating system of your Foreman server. Enter the following command:
```
# scp /etc/rndc.key root@foreman.example.com:/etc/rndc.key
```
To set the correct ownership, permissions, and SELinux context for the rndc.key file, enter the following command:
```
# restorecon -v /etc/rndc.key
# chown -v root:named /etc/rndc.key
# chmod -v 640 /etc/rndc.key
```
Assign the foreman-proxy user to the named group manually. Normally, foreman-installer ensures that the foreman-proxy user belongs to the named UNIX group, however, in this scenario Foreman does not manage users and groups, therefore you need to assign the foreman-proxy user to the named group manually.
```
# usermod -a -G named foreman-proxy
```

On Foreman server, enter the following foreman-installer command to configure Foreman to use the external DNS server:

# foreman-installer \
--foreman-proxy-dns=true \
--foreman-proxy-dns-managed=false \
--foreman-proxy-dns-provider=nsupdate \
--foreman-proxy-dns-server="IdM_Server_IP_Address" \
--foreman-proxy-keyfile=/etc/rndc.key \
--foreman-proxy-dns-ttl=86400

Testing External Updates to the DNS Zone in the IdM Server

Ensure that the key in the /etc/rndc.key file on Foreman server is the same key file that is used on the IdM server:
```
key "rndc-key" {
        algorithm hmac-md5;
        secret "secret-key==";
};
```
On Foreman server, create a test DNS entry for a host. For example, host test.example.com with an A record of 192.168.25.20 on the IdM server at 192.168.25.1.
```
# echo -e "server 192.168.25.1\n \
update add test.example.com 3600 IN A 192.168.25.20\n \
send\n" | nsupdate -k /etc/rndc.key
```

On Foreman server, test the DNS entry:

# nslookup test.example.com 192.168.25.1
Server:		192.168.25.1
Address:	192.168.25.1#53

Name:	test.example.com
Address: 192.168.25.20

To view the entry in the IdM web UI, navigate to Network Services > DNS > DNS Zones. Click the name of the zone and search for the host by name.

If resolved successfully, remove the test DNS entry:

# echo -e "server 192.168.25.1\n \
update delete test.example.com 3600 IN A 192.168.25.20\n \
send\n" | nsupdate -k /etc/rndc.key

Confirm that the DNS entry was removed:
```
# nslookup test.example.com 192.168.25.1
```
The above nslookup command fails and returns the SERVFAIL error message if the record was successfully deleted.

4.4.3. Reverting to Internal DNS Service

You can revert to using Foreman server and Smart Proxy server as your DNS providers. You can use a backup of the answer file that was created before configuring external DNS, or you can create a backup of the answer file. For more information about answer files, see Configuring Foreman server.

Procedure

On the Foreman or Smart Proxy server that you want to configure to manage DNS service for the domain, complete the following steps:

Configuring Foreman or Smart Proxy as a DNS Server

If you have created a backup of the answer file before configuring external DNS, restore the answer file and then enter the foreman-installer command:
```
# foreman-installer
```
If you do not have a suitable backup of the answer file, create a backup of the answer file now. To configure Foreman or Smart Proxy as DNS server without using an answer file, enter the following foreman-installer command on Foreman or Smart Proxy:
```
# foreman-installer \
--foreman-proxy-dns=true \
--foreman-proxy-dns-managed=true \
--foreman-proxy-dns-provider=nsupdate \
--foreman-proxy-dns-server="127.0.0.1"
```
For more information, see Configuring DNS, DHCP, and TFTP on Smart Proxy server.

After you run the foreman-installer command to make any changes to your Smart Proxy configuration, you must update the configuration of each affected Smart Proxy in the Foreman web UI.

Updating the Configuration in the Foreman web UI

In the Foreman web UI, navigate to Infrastructure > Smart Proxies.
For each Smart Proxy that you want to update, from the Actions list, select Refresh.
Configure the domain:
1. In the Foreman web UI, navigate to Infrastructure > Domains and click the domain name that you want to configure.
2. In the Domain tab, set DNS Smart Proxy to the Smart Proxy where the subnet is connected.
Configure the subnet:
1. In the Foreman web UI, navigate to Infrastructure > Subnets and select the subnet name.
2. In the Subnet tab, set IPAM to DHCP or Internal DB.
3. In the Domains tab, select the domain that you want to manage using Foreman or Smart Proxy.
4. In the Smart Proxies tab, set Reverse DNS Smart Proxy to the Smart Proxy where the subnet is connected.
5. Click Submit to save the changes.

5. Managing DHCP Using Smart Proxy

Foreman can integrate with a DHCP service using your Smart Proxy. A Smart Proxy has multiple DHCP providers that you can use to integrate Foreman with your existing DHCP infrastructure or deploy a new one. You can use the DHCP module of Smart Proxy to query for available IP addresses, add new, and delete existing reservations. Note that your Smart Proxy cannot manage subnet declarations.

Available DHCP providers

dhcp_infoblox – For more information, see Using Infoblox as DHCP and DNS Providers in Provisioning Hosts.
dhcp_isc – ISC DHCP server over OMAPI. For more information, see Configuring DNS, DHCP, and TFTP on Smart Proxy server in Installing an External Smart Proxy Server 3.5.
dhcp_remote_isc – ISC DHCP server over OMAPI with leases mounted through networking. For more information, see Configuring an External DHCP Server to Use with Smart Proxy server in Installing an External Smart Proxy Server 3.5.
dhcp_libvirt – dnsmasq DHCP via libvirt API

5.1. Configuring dhcp_libvirt

The dhcp_libvirt plugin manages IP reservations and leases using dnsmasq through the libvirt API. It uses ruby-libvirt to connect to the local or remote instance of libvirt daemon.

Procedure

You can use foreman-installer to configure dhcp_libvirt:

foreman-installer \
--foreman-proxy-dhcp true \
--foreman-proxy-dhcp-provider libvirt \
--foreman-proxy-libvirt-network default \
--foreman-proxy-libvirt-network qemu:///system

5.2. Securing the dhcpd API

Smart Proxy interacts with DHCP daemon using the dhcpd API to manage DHCP. By default, the dhcpd API listens to any host without access control. You can add an omapi_key to provide basic security.

Procedure

Install the required packages:
```
# dnf install bind-utils
```

Generate a key:

# dnssec-keygen -r /dev/urandom -a HMAC-MD5 -b 512 -n HOST omapi_key
# cat Komapi_key.+*.private | grep ^Key|cut -d ' ' -f2-

Use foreman-installer to secure the dhcpd API:

# foreman-installer \
--foreman-proxy-dhcp-key-name "My_Name" \
--foreman-proxy-dhcp-key-secret "My_Secret"

6. Managing DNS Using Smart Proxy

Foreman can manage DNS records using your Smart Proxy. DNS management contains updating and removing DNS records from existing DNS zones. A Smart Proxy has multiple DNS providers that you can use to integrate Foreman with your existing DNS infrastructure or deploy a new one.

After you have enabled DNS, your Smart Proxy can manipulate any DNS server that complies with RFC 2136 using the dns_nsupdate provider. Other providers provide more direct integration, such as dns_infoblox for Infoblox.

Available DNS Providers

dns_infoblox – For more information, see Using Infoblox as DHCP and DNS Providers in Provisioning Hosts.
dns_libvirt – Dnsmasq DNS via libvirt API. For more information, see Configuring dns_libvirt.
dns_nsupdate – Dynamic DNS update using nsupdate. For more information, see Using Infoblox as DHCP and DNS Providers in Provisioning Hosts.
dns_nsupdate_gss – Dynamic DNS update with GSS-TSIG. For more information, see Configuring Dynamic DNS Update with GSS-TSIG Authentication.
dns_powerdns – PowerDNS. For more information, see Configuring dns_powerdns.

For more information, see List of DNS plugins

6.1. Configuring dns_libvirt

The dns_libvirt DNS provider manages DNS records using dnsmasq through the libvirt API. It uses ruby-libvirt gem to connect to the local or a remote instance of libvirt daemon.

Procedure

You can use foreman-installer to configure dns_libvirt:

# foreman-installer \
--foreman-proxy-dns true \
--foreman-proxy-dns-provider libvirt \
--foreman-proxy-libvirt-network default \
--foreman-proxy-libvirt-url qemu:///system

Note that you can only use one network and URL for both dns_libvirt and dhcp_libvirt.

6.2. Configuring dns_powerdns

The dns_powerdns DNS provider manages DNS records using the PowerDNS REST API.

Procedure

You can use foreman-installer to configure dns_powerdns:

# foreman-installer \
--foreman-proxy-dns true \
--foreman-proxy-dns-provider powerdns \
--enable-foreman-proxy-plugin-dns-powerdns \
--foreman-proxy-plugin-dns-powerdns-rest-api-key api_key \
--foreman-proxy-plugin-dns-powerdns-rest-url http://localhost:8081/api/v1/servers/localhost

Appendix A: Smart Proxy Server Scalability Considerations

The maximum number of Smart Proxy servers that Foreman server can support has no fixed limit. It was tested that a Foreman server can support 17 Smart Proxy servers with 2 vCPUs. However, scalability is highly variable, especially when managing Puppet clients.

Smart Proxy server scalability when managing Puppet clients depends on the number of CPUs, the run-interval distribution, and the number of Puppet managed resources. Smart Proxy server has a limitation of 100 concurrent Puppet agents running at any single point in time. Running more than 100 concurrent Puppet agents results in a 503 HTTP error.

For example, assuming that Puppet agent runs are evenly distributed with less than 100 concurrent Puppet agents running at any single point during a run-interval, a Smart Proxy server with 4 CPUs has a maximum of 1250 – 1600 Puppet clients with a moderate workload of 10 Puppet classes assigned to each Puppet client. Depending on the number of Puppet clients required, the Foreman installation can scale out the number of Smart Proxy servers to support them.

If you want to scale your Smart Proxy server when managing Puppet clients, the following assumptions are made:

There are no external Puppet clients reporting directly to the Foreman integrated Smart Proxy.
All other Puppet clients report directly to an external Smart Proxy.
There is an evenly distributed run-interval of all Puppet agents.

Note	Deviating from the even distribution increases the risk of overloading Foreman server. The limit of 100 concurrent requests applies.

The following table describes the scalability limits using the recommended 4 CPUs.

Table 4. Puppet Scalability Using 4 CPUs
Puppet Managed Resources per Host	Run-Interval Distribution
1	3000 – 2500
10	2400 – 2000
20	1700 – 1400

The following table describes the scalability limits using the minimum 2 CPUs.

Table 5. Puppet Scalability Using 2 CPUs
Puppet Managed Resources per Host	Run-Interval Distribution
1	1700 – 1450
10	1500 – 1250
20	850 – 700

Appendix B: Troubleshooting DNF Modules

If DNF modules fails to enable, it can mean an incorrect module is enabled. In that case, you have to resolve dependencies manually as follows. List the enabled modules:

# dnf module list --enabled

Ruby

If Ruby module fails to enable, it can mean an incorrect module is enabled. In that case, you have to resolve dependencies manually as follows:

List the enabled modules:

# dnf module list --enabled

If the Ruby 2.5 module has already been enabled, perform a module reset:

# dnf module reset ruby

Appendix C: dhcp_isc Settings

The dhcp_isc provider uses a combination of the ISC DHCP server OMAPI management interface and parsing of configuration and lease files. This requires it to be run on the same host as the DHCP server. The following settings are defined in dhcp_isc.yml:

Configuring the path to the config and leases files:

:config: /etc/dhcp/dhcpd.conf
:leases: /var/lib/dhcpd/dhcpd.leases

Securing the DHCP server with an omapi_key

:key_name: My_OMAPI_Key
:key_secret: My_Key_Secret

Setting a port on which the DHCP server listens

:omapi_port: My_DHCP_Server_Port  # default: 7911

The server is defined in dhcp.yml:

Setting the host on which the DHCP server runs on

:server: My_DHCP_Server_FQDN

Appendix D: DHCP Options for Network Configuration

--foreman-proxy-dhcp: Enables the DHCP service. You can set this option to true or false.
--foreman-proxy-dhcp-managed: Enables Foreman to manage the DHCP service. You can set this option to true or false.
--foreman-proxy-dhcp-gateway: The DHCP pool gateway. Set this to the address of the external gateway for hosts on your private network.
--foreman-proxy-dhcp-interface: Sets the interface for the DHCP service to listen for requests. Set this to eth1.
--foreman-proxy-dhcp-nameservers: Sets the addresses of the nameservers provided to clients through DHCP. Set this to the address for Foreman server on eth1.
--foreman-proxy-dhcp-range: A space-separated DHCP pool range for Discovered and Unmanaged services.
--foreman-proxy-dhcp-server: Sets the address of the DHCP server to manage.

Run foreman-installer --help to view more options related to DHCP and other Smart Proxy services.