CentOS 8 DHCP client not sending hostname or vendor class identifier

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jkaberna
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Joined: 2020/05/02 01:34:01

CentOS 8 DHCP client not sending hostname or vendor class identifier

Post by jkaberna » 2020/05/08 02:07:36

I'm a network engineer doing a NAC project for Cisco ISE. We need to make sure that the various Linux boxes announce what they are in their DHCP request so they can be profiled correctly and put in the right VLAN. For some reason it doesn't appear to be working. Below is a copy of my /etc/dhcp/dhclient.conf file.

# DHCP Client Configuration file.
# see /usr/share/doc/dhclient/dhclient.conf.example
# see dhclient.conf(5) man page
#
# Send client identifier as "hardware-type.link-layer address" (e.g. "1.c2.23.7d.c3.52.2c")
# Required in environments where a bridge might be clobbering the forwarded
# packet's MAC address (common in Wifi, Docsis, or ADSL bridging scenarios)
# see dhcp-options(5) man page for 'dhcp-client-identifier'
# see dhcp-eval(5) man page for 'hardware'
send host-name = pick-first-value(gethostname(), "ISC-dhclient");
send vendor-class-identifier "CentOS Linux";

I also attached some of the leases in my DHCP server. The CentOS box is the Mac ending in ea:ba with the IP 192.168.0.78. Other Linux boxes including my Rasperry Pi send the VCI without having to change any files. My guess is that my syntax is wrong or that this file is not actually being used when it brings up networking. Hoping someone in here ran in to this already and knows the answer. Thanks in advance!
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Firewall DHCP lease.png
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TrevorH
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Re: CentOS 8 DHCP client not sending hostname or vendor class identifier

Post by TrevorH » 2020/05/08 15:32:55

hostnamectl set-hostname $yourhostname
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jkaberna
Posts: 2
Joined: 2020/05/02 01:34:01

Re: CentOS 8 DHCP client not sending hostname or vendor class identifier

Post by jkaberna » 2020/05/08 18:27:55

Thanks Trevor. It is now sending the hostname. Any idea how to get it to send the VCI? That's really the important part.
DHCP - hostname now showing.png
DHCP - hostname now showing.png (38.29 KiB) Viewed 213 times

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