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Merge pull request #78594 from slovern/OCPBUGS-34715
OCPBUGS-34715 - troubleshooting DNS in disconnected environment
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‎modules/k8s-nmstate-troubleshooting-dns-disconnected-env-dnsmasq.adoc

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// Module included in the following assemblies:
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//
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// * networking/k8s_nmstate/k8s-nmstate-troubleshooting-node-network.adoc
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:_mod-docs-content-type: PROCEDURE
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[id="troubleshooting-dns-disconnected-env-dnsmasq_{context}"]
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= Configuring the dnsmasq DNS server
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If you are using `dnsmasq` as the DNS server, you can delegate resolution of the `root-servers.net` domain to another DNS server, for example, by creating a new configuration file that resolves `root-servers.net` using a DNS server that you specify.
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. Create a configuration file that delegates the domain `root-servers.net` to another DNS server by running the following command:
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[source,terminal]
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----
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$ echo 'server=/root-servers.net/<DNS_server_IP>'> /etc/dnsmasq.d/delegate-root-servers.net.conf
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----
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. Restart the `dnsmasq` service by running the following command:
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[source,terminal]
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----
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$ systemctl restart dnsmasq
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----
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. Confirm that the `root-servers.net` domain is delegated to another DNS server by running the following command:
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[source,terminal]
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----
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$ journalctl -u dnsmasq|grep root-servers.net
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----
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.Example output
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[source,terminal]
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----
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Jul 03 15:31:25 rhel-8-10 dnsmasq[1342]: using nameserver 192.168.1.1#53 for domain root-servers.net
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----
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. Verify that the DNS server can resolve the NS record for the `root-servers.net` domain by running the following command:
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[source,terminal]
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----
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$ host -t NS root-servers.net. 127.0.0.1
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----
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.Example output
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[source,terminal]
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----
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Using domain server:
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Name: 127.0.0.1
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Address: 127.0.0.1#53
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Aliases:
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root-servers.net name server root-servers.net.
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----

‎modules/k8s-nmstate-troubleshooting-dns-disconnected-env.adoc

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// Module included in the following assemblies:
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//
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// * networking/k8s_nmstate/k8s-nmstate-troubleshooting-node-network.adoc
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:_mod-docs-content-type: PROCEDURE
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[id="troubleshooting-dns-disconnected-env_{context}"]
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= Troubleshooting DNS connectivity issues in a disconnected environment
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If you experience DNS connectivity issues when configuring `nmstate` in a disconnected environment, you can configure the DNS server to resolve the list of name servers for the domain `root-servers.net`.
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== Configuring the bind9 DNS named server
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For a cluster configured to query a `bind9` DNS server, you can add the `root-servers.net` zone to a configuration file that contains at least one NS record.
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For example you can use the `/var/named/named.localhost` as a zone file that already matches this criteria.
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.Procedure
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. Add the `root-servers.net` zone at the end of the `/etc/named.conf` configuration file by running the following command:
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[source,terminal]
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----
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$ cat >> /etc/named.conf <<EOF
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zone "root-servers.net" IN {
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type master;
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file "named.localhost";
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};
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EOF
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----
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. Restart the `named` service by running the following command:
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[source,terminal]
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----
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$ systemctl restart named
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----
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. Confirm that the `root-servers.net` zone is present by running the following command:
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[source,terminal]
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----
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$ journalctl -u named|grep root-servers.net
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----
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.Example output
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[source,terminal]
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----
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Jul 03 15:16:26 rhel-8-10 bash[xxxx]: zone root-servers.net/IN: loaded serial 0
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Jul 03 15:16:26 rhel-8-10 named[xxxx]: zone root-servers.net/IN: loaded serial 0
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----
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. Verify that the DNS server can resolve the NS record for the `root-servers.net` domain by running the following command:
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[source,terminal]
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----
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$ host -t NS root-servers.net. 127.0.0.1
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----
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.Example output
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[source,terminal]
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----
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Using domain server:
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Name: 127.0.0.1
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Address: 127.0.0.53
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Aliases:
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root-servers.net name server root-servers.net.
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----

‎networking/k8s_nmstate/k8s-nmstate-troubleshooting-node-network.adoc

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* The host loses connection to the API server.
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include::modules/virt-troubleshooting-incorrect-policy-config.adoc[leveloffset=+1]
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include::modules/k8s-nmstate-troubleshooting-dns-disconnected-env.adoc[leveloffset=+1]
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include::modules/k8s-nmstate-troubleshooting-dns-disconnected-env-dnsmasq.adoc[leveloffset=+2]

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