<div dir="ltr"><div>Hi Dipesh,</div><div><br></div><div>This is not currently supported. You can open an issue here: <a href="https://gitlab.isc.org/isc-projects/kea/-/issues/">https://gitlab.isc.org/isc-projects/kea/-/issues/</a> requesting the support be added.</div><div><br></div><div>Thank you,</div><div>Darren Ankney</div></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Fri, Jun 13, 2025 at 2:13 AM Dipesh Kayastha <<a href="mailto:er.dipesh.kayastha@gmail.com">er.dipesh.kayastha@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><p>Dear Kea Development Team,</p><p>I am currently working on migrating configurations from ISC DHCP (dhcpd) to Kea DHCP and encountered a limitation regarding the <code>next-server</code> field.</p><p>In ISC DHCP, it is valid to specify either an IP address or a fully qualified domain name (FQDN) for the <code>next-server</code> directive, as referenced in the dhcpd.conf man page:<br>
<a rel="noopener" href="https://linux.die.net/man/5/dhcpd.conf" target="_blank">https://linux.die.net/man/5/dhcpd.conf</a></p><p>However, in Kea, the <code>next-server</code> field under <code>subnet4</code> appears to accept only IPv4 addresses. If an FQDN is used (e.g., <code>"next-server": "<a href="http://pxe.boot.example.com" target="_blank">pxe.boot.example.com</a>"</code>), the configuration fails to parse and returns an error like:</p><pre><div><div dir="ltr"></div></div></pre><p><br><strong style="color:rgb(23,43,77);font-family:-apple-system,"system-ui","Segoe UI",Roboto,Oxygen,Ubuntu,"Fira Sans","Droid Sans","Helvetica Neue",sans-serif;font-size:14px;letter-spacing:-0.07px">2025-06-12 13:35:40.228 ERROR [kea-dhcp4.dhcp4/1.140187402663808] DHCP4_CONFIG_LOAD_FAIL configuration error using </strong><span style="color:rgb(23,43,77);font-family:-apple-system,"system-ui","Segoe UI",Roboto,Oxygen,Ubuntu,"Fira Sans","Droid Sans","Helvetica Neue",sans-serif;font-size:14px;letter-spacing:-0.07px"><strong>file: /etc/config/kea4.conf</strong></span><strong style="color:rgb(23,43,77);font-family:-apple-system,"system-ui","Segoe UI",Roboto,Oxygen,Ubuntu,"Fira Sans","Droid Sans","Helvetica Neue",sans-serif;font-size:14px;letter-spacing:-0.07px">, reason: subnet configuration failed: invalid parameter next-server : </strong><span style="font-family:monospace"><a href="http://pxe.boot.example.com" target="_blank">pxe.boot.example.com</a></span><strong style="color:rgb(23,43,77);font-family:-apple-system,"system-ui","Segoe UI",Roboto,Oxygen,Ubuntu,"Fira Sans","Droid Sans","Helvetica Neue",sans-serif;font-size:14px;letter-spacing:-0.07px">(/etc/config/kea4.conf:169:24)
</strong></p><p>This becomes a compatibility issue during migration, especially in environments that rely on DNS to resolve boot server IPs dynamically.</p><p>However, ISC DHCP (dhcpd) supports both IP addresses and FQDNs in the <code>next-server</code> field, as documented here:<strong style="color:rgb(23,43,77);font-family:-apple-system,"system-ui","Segoe UI",Roboto,Oxygen,Ubuntu,"Fira Sans","Droid Sans","Helvetica Neue",sans-serif;font-size:14px;letter-spacing:-0.07px">
</strong></p><p>
<a rel="noopener" href="https://linux.die.net/man/5/dhcpd.conf" target="_blank">https://linux.die.net/man/5/dhcpd.conf</a><br></p><img src="cid:ii_mbueqsej0" alt="image.png" width="542" height="82"><p><br></p><p>Is there any plan to support FQDNs in Kea for the <code>next-server</code> field, similar to how ISC DHCP handles it? FQDN support can be useful in dynamic environments where the boot server’s IP address may change and is managed via DNS.</p><p>I'm looking forward to hearing back from you<br><br><br>Regards,<br>.Dipesh</p><p>
<span style="color:rgb(23,43,77);font-family:-apple-system,"system-ui","Segoe UI",Roboto,Oxygen,Ubuntu,"Fira Sans","Droid Sans","Helvetica Neue",sans-serif;font-size:14px;letter-spacing:-0.07px">
</span></p></div>
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