GH-44381:adds to IMPORTANT message

Author: JoeAldinger

modules/nw-egressnetworkpolicy-about.adoc

@@ -41,8 +41,7 @@ endif::ovn[]
 
 [IMPORTANT]
 ====
-If your egress firewall includes a deny rule for `0.0.0.0/0`, access to your {product-title} API servers is blocked.
-To ensure that pods can continue to access the {product-title} API servers, you must include the IP address range that the API servers listen on in your egress firewall rules, as in the following example:
+If your egress firewall includes a deny rule for `0.0.0.0/0`, access to your {product-title} API servers is blocked. To ensure that pods can access the {product-title} API servers, you must include the built-in join network `100.64.0.0/16` of Open Virtual Network (OVN) to allow access when using node ports together with an EgressFirewall. You must also include the IP address range that the API servers listen on in your egress firewall rules, as in the following example:
 
 [source,yaml,subs="attributes+"]
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