[CentOS] Centos 7 dhcpd failure to allow a 2nd network over same interal nic

[James Hogarth]

On 14 Jan 2017 8:01 pm, "Gregory P. Ennis" <PoMec at pomec.net> wrote:

Everyone,

I am trying to set up a second internal network  (192.168.0.0/24) and
have not been able to get dhcp to start when I have the following in my
dhcpd.conf file :

subnet 192.168.0.0 netmask 255.255.255.0 {
        range 192.168.0.110 192.168.0.130;
        option subnet-mask 255.255.255.0;
        option broadcast-address 192.168.0.255;
        option routers 192.168.0.1;
        option domain-name-servers 192.168.0.1;
}

When i remove the above from dhcpd.conf dhcpd works perfectly

I have my internal nic card set with two ip addresses one of which is
192.168.0.1. the other address is my standard internal network address.

I have also set up the domain server to allow access from
192.168.0.0/24, and the firewall allows internal access to the same
subnet.

The error that I get is the following :

Job for dhcpd.service failed because the control process exited with error
code. See "systemctl status dhcpd.service" and "journalctl -xe" for details.

When I evaluate journalctl -xe the following is obtained :

dhcpd[18763]: Internet Systems Consortium DHCP Server 4.2.5
dhcpd[18763]: Copyright 2004-2013 Internet Systems Consortium.
dhcpd[18763]: All rights reserved.
dhcpd[18763]: For info, please visit https://www.isc.org/software/dhcp/
dhcpd[18763]: Not searching LDAP since ldap-server, ldap-port and
ldap-base-dn were not specified in the config file
dhcpd[18763]: Internet Systems Consortium DHCP Server 4.2.5
dhcpd[18763]: Copyright 2004-2013 Internet Systems Consortium.
dhcpd[18763]: All rights reserved.
dhcpd[18763]: For info, please visit https://www.isc.org/software/dhcp/
dhcpd[18763]: Wrote 0 deleted host decls to leases file.
dhcpd[18763]: Wrote 0 new dynamic host decls to leases file.
dhcpd[18763]: Wrote 2 leases to leases file.
dhcpd[18763]: Interface enp0s29u1u2 matches multiple shared networks
dhcpd[18763]:
dhcpd[18763]: This version of ISC DHCP is based on the release available
dhcpd[18763]: on ftp.isc.org.  Features have been added and other
changes
dhcpd[18763]: have been made to the base software release in order to
make
dhcpd[18763]: it work better with this distribution.
dhcpd[18763]:
dhcpd[18763]: Please report for this software via the CentOS Bugs
Database:
dhcpd[18763]:     http://bugs.centos.org/
dhcpd.service: main process exited, code=exited, status=1/FAILURE
dhcpd[18763]:
systemd[1]: Failed to start DHCPv4 Server Daemon.

When I review the information about dhcpd it appears that it can manage
the ip addresses for two networks on different nic cards, but is there a
problem in having it manage two networks on the same nic card?

Does anyone have any ideas?  Would sure appreciate your help.


Can you be a little clearer in what you're trying to do, as in the end goal
you are trying to reach?

Having dhcp for two different networks on the same physical network is just
not going to work in any sane fashion...

If you want to serve different dhcp pools to different physical networks
then you could do that via vlan and trunking from the switch to the server
or just ip-helper configuration on the router between the network
boundaries.