Documented additional ports required for ECE containers to communicate on the same host. (#4050)

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## Summary
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This PR adds documentation for additional ports that must be open to
enable proper communication between containers on the same host in an
ECE setup.

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Author: gheorghepucea

deploy-manage/deploy/cloud-enterprise/ece-networking-prereq.md

@@ -16,9 +16,9 @@ For versions 2.4.0 and 2.4.1, IPv6 should remain enabled on any host with the Pr
 
 * [Inbound traffic](#ece-inbound)
 * [Outbound traffic](#ece-outbound)
+* [Container communication on the same host](#ece-container-communication-on-same-host)
 * [Hosts in multiple data centers](#ece-multiple-data-centers)
 
-
 ## Inbound traffic [ece-inbound]
 
 When there are multiple hosts for each role, the inbound networking and ports can be represented by the following diagram:
@@ -68,6 +68,21 @@ Outbound traffic must also permit connections to the [snapshot repositories](../
 ::::
 
 
+## Container communication on the same host [ece-container-communication-on-same-host]
+
+The following ports need to be open for containers communicating with the host or with each other on the same host:
+
+| Port(s) | Purpose | Host role |
+| --- | --- | --- |
+| 53 | DNS resolver | All roles |
+| 2180 | ZooKeeper admin port | All roles |
+| 2375 | Docker admin port | All roles |
+| 2191-2199 | Debug ports | Director |
+| 5000-5010 | Java Virtual Machine (JVM)/debug ports | All roles |
+| 8080-8084 | Health/monitoring ports | All roles |
+| 9000, 9043 | Internal proxy use | Proxy |
+| 9244 | Internal proxy port | All roles |
+
 
 ## Hosts in multiple data centers [ece-multiple-data-centers]