Added Pull-DP to DP configured as source

Even though the client on the Pull-DP is doing the download and there is a rule for client --> DP already it might make sense to also mention Pull-DP to Pull-Source as an extra rule. Especially when the Pull-DPs client would normally not reach the source DP due to a firewall in between.

Author: jonasatgit

memdocs/configmgr/core/plan-design/hierarchy/ports.md

@@ -370,6 +370,15 @@ A distribution point communicates to the management point in the following scena
 |-----------------|---------|---------|
 |HTTPS|--|443|
 
+### <a name="BKMK_PortsPullDP-DPSource"></a> Pull-Distribution point `-->` Distribution point configured as source
+
+|Description|UDP|TCP|
+|-----------------|---------|---------|
+|HTTP|--|80 <sup>[Note 2](#bkmk_note2) Alternate port available</sup>|
+|HTTPS|--|443 <sup>[Note 2](#bkmk_note2) Alternate port available</sup>|
+|Express updates|--|8005 <sup>[Note 2](#bkmk_note2) Alternate port available</sup><!-- SCCMDocs#2091 -->|
+
+
 ### <a name="BKMK_PortsRSP-SQL"></a> Reporting Services point `-->` SQL Server
 
 |Description|UDP|TCP|