Configure hostapd with separate dhcp_server - Error: unknown configuration item "dhcp_server"

[Dan Hayes]

I've installed AlmaLinux 9.0 on a machine with eth/wifi ports. The
machine connects to my network via ethernet. I want to set the machine
up as an AP for wifi clients within range using hostapd. I've
installed hostapd-2.10-1.el9.x86_64.

I have everything working except DHCP. If I manually configure IP/DNS
on wireless client and then connect to hostapd, the wireless client
works fine.  Since I already have a DHCP server on the network and
want to setup multiple linux hostapd servers in different locations, I
want to use a single DHCP instance for all hostapd servers.

If I'm understanding it correctly, the documentation in
/usr/share/doc/hostapd/hostapd.conf seems to support this:

    # DHCP server for FILS HLP
    # If configured, hostapd will act as a DHCP relay for all FILS HLP requests
    # that include a DHCPDISCOVER message and send them to the specific DHCP
    # server for processing. hostapd will then wait for a response
from that server
    # before replying with (Re)Association Response frame that encapsulates this
    # DHCP response. own_ip_addr is used as the local address for the
communication
    # with the DHCP server.
    #dhcp_server=127.0.0.1

    # DHCP server UDP port
    # Default: 67
    #dhcp_server_port=67

    # DHCP relay UDP port on the local device
    # Default: 67; 0 means not to bind any specific port
    #dhcp_relay_port=67

    # DHCP rapid commit proxy
    # If set to 1, this enables hostapd to act as a DHCP rapid commit proxy to
    # allow the rapid commit options (two message DHCP exchange) to be
used with a
    # server that supports only the four message DHCP exchange. This
is disabled by
    # default (= 0) and can be enabled by setting this to 1.
    #dhcp_rapid_commit_proxy=0

But when I add those lines to the end of my /etc/hostapd/hostapd.conf file

    87 dhcp_server=192.168.1.1
    88 dhcp_server_port=67
    89 dhcp_relay_port=67
    90 dhcp_rapid_commit_proxy=0

I get an error:

    Oct 13 15:56:58 localhost.localdomain hostapd[33576]: Line 87:
unknown configuration item 'dhcp_server'
    Oct 13 15:56:58 localhost.localdomain hostapd[33576]: Line 88:
unknown configuration item 'dhcp_server_port'
    Oct 13 15:56:58 localhost.localdomain hostapd[33576]: Line 89:
unknown configuration item 'dhcp_relay_port'
    Oct 13 15:56:58 localhost.localdomain hostapd[33576]: Line 90:
unknown configuration item 'dhcp_rapid_commit_proxy'
    Oct 13 15:56:58 localhost.localdomain hostapd[33576]: 4 errors
found in configuration file '/etc/hostapd/hostapd.conf'

*Note - the server at 192.168.1.1 is another linux machine running
AlmaLinux 9 and dhcp-server-4.4.2-16.b1.el9.x86_64

For completeness, here is my entire /etc/hostapd/hostapd.conf file
with comments removed:

    interface=wlp2s0
    bridge=br0
    driver=nl80211
    logger_stdout=-1
    logger_stdout_level=2
    ctrl_interface=/var/run/hostapd
    ctrl_interface_group=wheel
    ssid=MyNetworkName
    country_code=US
    hw_mode=g
    channel=7
    max_num_sta=5
    macaddr_acl=0
    auth_algs=1
    ignore_broadcast_ssid=0
    wmm_enabled=1
    ieee80211n=1
    ht_capab=[HT40+][SHORT-GI-40][TX-STBC][RX-STBC1][DSSS_CCK-40]
    own_ip_addr=192.168.1.4
    wpa=2
    wpa_passphrase=MyWirelessPassword
    wpa_key_mgmt=WPA-PSK
    wpa_pairwise=CCMP
    dhcp_server=192.168.1.1
    dhcp_server_port=67
    dhcp_relay_port=67
    dhcp_rapid_commit_proxy=0

>From "Minimal Install" of AlmaLinux 9, my setup scripts looks like this:

    dnf -y update
    shutdown -r now
    dnf -y install epel-release
    dnf -y groupinstall "Development Tools"
    dnf -y install vim-enhanced mlocate git nmap pv tmux wget unzip
nethogs iftop rsync htop tcpdump net-tools bind-utils iw
    dnf -y install hostapd
    systemctl enable hostapd.service

    nmcli conn add type bridge con-name br0 ifname br0
    nmcli conn modify br0 ipv4.addresses '192.168.1.5/24'
    nmcli conn modify br0 ipv4.gateway '192.168.1.1'
    nmcli conn modify br0 ipv4.dns '192.168.1.1'
    nmcli conn modify br0 ipv4.method manual
    nmcli conn add type ethernet slave-type bridge con-name bridge-br0
ifname enp1s0 master br0
    nmcli conn up br0

    cat > /etc/hostapd/hostapd.conf <<EOF
    interface=wlp2s0
    bridge=br0
    driver=nl80211
    logger_stdout=-1
    logger_stdout_level=2
    ctrl_interface=/var/run/hostapd
    ctrl_interface_group=wheel
    ssid=MyNetworkName
    country_code=US
    hw_mode=g
    channel=7
    max_num_sta=5
    macaddr_acl=0
    auth_algs=1
    ignore_broadcast_ssid=0
    wmm_enabled=1
    ieee80211n=1
    ht_capab=[HT40+][SHORT-GI-40][TX-STBC][RX-STBC1][DSSS_CCK-40]
    own_ip_addr=192.168.1.4
    wpa=2
    wpa_passphrase=MyWirelessPassword
    wpa_key_mgmt=WPA-PSK
    wpa_pairwise=CCMP
    EOF

    systemctl restart hostapd.service


Do I need to install other packages to get hostapd to recognize the
dhcp_server variable? Do I need to include other variables? I've
googled quite a bit, but I can't find many instances of people setting
up hostapd with a remote dhcp server.  And without configuring a DHCP
client on the hostapd server, would it get DHCP information
automatically if I removed a firewall block?  Is there maybe an
iptables entry that would open this up for me?

I've read everything I can find searching google, but nothing I've
tried has worked.