BZ2070016: Adds a section to increase network MTU..

Author: johnwilkins

modules/ipi-install-network-requirements.adoc

@@ -9,6 +9,12 @@ Installer-provisioned installation of {product-title} involves several network r
 
 image::210_OpenShift_Baremetal_IPI_Deployment_updates_0122_2.png[Installer-provisioned networking]
 
+
+[id="network-requirements-increase-mtu_{context}"]
+== Increase the network MTU
+
+Before deploying {product-title}, increase the network maximum transmission unit (MTU) to 1500 or more. If the MTU is lower than 1500, the Ironic image that is used to boot the node might fail to communicate with the Ironic inspector pod, and inspection will fail. If this occurs, installation stops because the nodes are not available for installation. 
+
 [id='network-requirements-config-nics_{context}']
 == Configuring NICs
 
@@ -154,4 +160,4 @@ You can reconfigure the control plane nodes to act as NTP servers on disconnecte
 [id='network-requirements-out-of-band_{context}']
 == Port access for the out-of-band management IP address
 
-The out-of-band management IP address is on a separate network from the node. To ensure that the out-of-band management can communicate with the `baremetal` node during installation, the out-of-band management IP address must be granted access to port `6180`.
+The out-of-band management IP address is on a separate network from the node. To ensure that the out-of-band management can communicate with the `baremetal` node during installation, the out-of-band management IP address must be granted access to port `6180`.