by: adminPosted on:

systemd-networkd DHCP server Failed to configure address pool for DHCPv4 server instance: Numerical result out of range

I am using systemd networkd version 253.1. I have 2 ethernet ports on my Linux 5.15 box and I want to setup a DHCP server on the second port. I had successfully done that with the following configuration for eth1.

Working DHCP Server configuration:

[Match]
Name=eth1
Type=ether

[DHCPV4]
DUIDType=link-layer
ClientIdentifier=mac

[Network]
Address=172.1.17.1/24
DHCPServer=yes
#IPMasquerade=ipv4

[DHCPServer]
PoolOffset=1
PoolSize=8

Now, I want the change the range to the following:

[Match]
Name=eth1
Type=ether

[DHCPV4]
DUIDType=link-layer
ClientIdentifier=mac

[Network]
#
# 10.1.193.24/29
#
#  Network Address: 10.1.193.24
#  Usable IP Range: 10.1.193.25 - 10.1.193.30
#  Broadcast Address: 10.1.193.31
#
Address= 10.1.193.24/29
DHCPServer=yes
#IPMasquerade=ipv4

[DHCPServer]
PoolOffset=2
PoolSize=5

However, I get the error shown below:

[root@machine ~]$  networkctl status eth1 -l
* 3: eth1
                     Link File: n/a
                  Network File: /etc/systemd/network/eth1.network
                         State: routable (failed)
                  Online state: online
                          Type: ether
                          Path: platform-30bf0000.ethernet
              Hardware Address: 00:01:c0:37:6d:56 (Company, Ltd.)
                           MTU: 1500 (min: 46, max: 9000)
                         QDisc: mq
  IPv6 Address Generation Mode: eui64
      Number of Queues (Tx/Rx): 8/8
              Auto negotiation: yes
                         Speed: 1Gbps
                        Duplex: full
                          Port: tp
                       Address: 10.1.193.24
                                fe80::201:c0ff:fe37:6d56
             Activation Policy: up
           Required For Online: yes
             DHCP6 Client DUID: DUID-EN/Vendor:0000ab1180dd9f24e9435b570000
           Offered DHCP leases: none

Aug 12 14:33:07 machine systemd-networkd[654]: eth1: Received new foreign route (configured): dst: 10.1.193.24/29, src: n/a, gw: n/a, prefsrc: 10.1.193.24, scope: link, table: main(254), proto: kernel, type: unicast, nexthop: 0, priority: 0, flags: n/a
Aug 12 14:33:07 machine systemd-networkd[654]: eth1: Addresses set
Aug 12 14:33:07 machine systemd-networkd[654]: eth1: link_check_ready(): dynamic addresses or routes are not configured.
Aug 12 14:33:07 machine systemd-networkd[654]: eth1: Configuring DHCP Server.
Aug 12 14:33:07 machine systemd-networkd[654]: eth1: Failed to configure address pool for DHCPv4 server instance: Numerical result out of range
Aug 12 14:33:07 machine systemd-networkd[654]: eth1: Failed to configure DHCP server: Numerical result out of range
Aug 12 14:33:07 machine systemd-networkd[654]: eth1: Failed
Aug 12 14:33:07 machine systemd-networkd[654]: eth1: State changed: configuring -> failed
Aug 12 14:33:07 machine systemd-networkd[654]: eth1: LLDP Rx: Stopping LLDP client
Aug 12 14:33:07 machine systemd-networkd[654]: eth1: NDISC: Stopping IPv6 Router Solicitation client

I’ve checked various CIDR calculators and I believe my configuration file parameters are valid.

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Why does networkd not accept my config file?