Enable Azure Update Management in Azure Firewall


azure

When you have Windows VM’s in an Azure network and internet traffic is routed through your Azure Firewall, and you need to allow them to update, either with Automatic updates, or Azure Update management. There are a few things you need to allow to get through your FW.
Add the following rules and you will have it up and running in no time.

Go to the Azure Firewall in the Azure portal.
Rules -> Application Rule Collection
+ Add application rule collection

Rule 1
Name: Windows_Update (No whitespace)
Priority: 2000 (A number between 100-65000)
Action: Allow
Rule, FQDN Tags:
Name:Windows Update
Source Type: IP Address
Source: Prefix of vNet/Subnet or host, ex. 10.1.0.0/22
FQDN tags: WindowsUpdate (Select in the dropdown)

Rule 2
Name: Monitoring_Agent (No whitespace)
Priority: 2100 (A number between 100-65000)
Action: Allow
Rule, Target FQDNs:
Name:OMS Agent
Source Type: IP Address
Source: Prefix of vNet/Subnet or host, ex. 10.1.0.0/22
Protocol:Port: https:443
Target FQDNs: *.ods.opinsights.azure.com,*.oms.opinsights.azure.com,*.blob.core.windows.net

Rule 3
Name: Hybrid_Runbook_Worker (No whitespace)
Priority: 2200 (A number between 100-65000)
Action: Allow
Rule, Target FQDNs:
Name:Hybrid Runbook Worker
Source Type: IP Address
Source: Prefix of vNet/Subnet or host, ex. 10.1.0.0/22
Protocol:Port: https:443
Target FQDNs: *.azure-automation.net

 

References

FQDN tags overview
https://docs.microsoft.com/en-us/azure/firewall/fqdn-tags

Connect Operations Manager to Azure Monitor
https://docs.microsoft.com/en-us/azure/azure-monitor/platform/om-agents

Hybrid Runbook Worker overview
https://docs.microsoft.com/en-us/azure/automation/automation-hybrid-runbook-worker

 

Thanks to:
Joakim Gräns – Asurgent AB


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Enjoy!

Regards

 Thomas Odell Balkeståhl on LinkedIn

 

Azure Firewall and DNS forward timeout – SNAT UDP utilization at 100%


azure

Issue:

External DNS queries dropped causing timeouts and unresponsive services, web-browsing, Office 365, Windows Virtual Desktop(WVD), etc.

(Resolution at the end…)

Azure based environment.
Classic AD with a few VM based Domain controllers in Azure.
DC’s are acting as the primary DNS service for all servers, services and clients in the environment.
Azure firewall is configured as the primary firewall solution for the Azure based environments.
The subnet(s) where the DC’s are located are routed (UDR) to use the Azure Firewall for outgoing internet traffic
The DC’s IP are the added as the primary and secondary DNS for all vNets in Azure, for office subnets, VPN, etc.
DNS service on the DC’s are configured to forward external DNS queries, as is the default, either a custom Forwarder, or the DNS hints.

As the workload increases, you may notice a congestion in the Azure Firewall, at a certain amount of external forwarded DNS queries, the Azure Firewall will choke at 100%.
You may notice this as a user, when simple internet pages in a browser no longer opens, if you use WVD, the environment may stop responding all together due to the lack of DNS service in the WVD hostpool.
As an admin, you may see that a repeated number of NSLOOKUP to an external address, will result in intermittent timeouts.

Azure Firewall.
A part of the DNS service is that it uses UDP, and Azure Firewall uses SNAT for address translation from every internal source, resulting in every UDP request from one IP to an external provider (8.8.8.8, 8.8.4.4, 1.1.1.1 etc.) will use one port out of the 65.000 available in the TCP protocol for that unique destination. When the number of DNS requests to the same address (say google.com) gets repeated, every request gets its own port, and after a while, all 65.000 are taken. Causing congestion in the Firewall and it starts to drop requests. Two requests to google.com and two to microsoft.com will thus result in 4 ports being used, while single requests to 1000 different addresses will only use the one port.

In our case, we saw that during office hours, after enough users and systems were migrated, the Firewall reached 100% in UDP SNAT utilization, causing timeouts on our DNS servers (DC’s) causing services and systems to fail.

Issue can clearly be seen starting at the beginning of day on Thursday July 2nd, then on Friday July 3rd, stopped over the weekend, then up again on Monday July 6th. The graph also shows that we have users in Europe as well as in America, which prolongs the period a bit.

After some t-shooting, severity A case with Microsoft premier support and help from Microsoft FastTrack, we had two ways to quickly mitigate the problem and get the services operational again.

Resolution

  1. For us, the fastest we could implement, was to add a second public IP on the Azure Firewall, doubling the amount of ports used for SNAT to 130.000 (65.000 x2). REMEMBER, you cannot control what goes to what port, so if any of your internal servers or systems connect to an external service, and the Azure Firewalls public IP is whitelisted, you have to add this second IP to the whitelist as well. Every place that has it whitelisted. This because Azure Firewall randomly selects the public IP to use for outgoing traffic.
    This immediately reduced the UDP SNAT util from 100%+ to 60-70%

    The utilization quickly dropped, to about 60-70%
  2. The best solution, which we implemented a few minutes later, is to add Microsofts Azure ‘public’ DNS IP as the forward DNS server on our DNS servers (the DC’s). This is an Azure Datacenter service, and as such, it will be recognized and accesses using the Azure backbone and never going through the Azure Firewall at all. This reduced the load from 60-70% on UDP SNAT to 0%!
    The IP to use is: 168.63.129.16 (This will only be accessible from Azure environments, do NOT use on onprem DNS servers!)

    The utilization here dropped completely to 0%, since all DNS queries now go to the Azure ‘internal’ DNS

Microsoft Azure DNS IP: 168.63.129.16

 

Azure Firewall SNAT private IP address ranges
https://technet.microsoft.com/en-us/library/mt683473(v=office.16).aspx

Deploy an Azure Firewall with multiple public IP addresses using Azure PowerShell
https://docs.microsoft.com/en-us/azure/firewall/deploy-multi-public-ip-powershell

Thanks to:
Thomas Vuylsteke – Microsoft Azure Fasttrack team
Microsoft Premier Support
Akelius Residential Property AB (Martin Supan, Mattias Segerström)


___________________________________________________________________________________________________

Enjoy!

Regards

 Thomas Odell Balkeståhl on LinkedIn

 

TCP/IP Ports of SharePoint 2016


SharePoint 2016 huh?!
(Long time since I last posted anything real here…)

Actually, this post is by popular demand 🙂 This is the 2016 version of the post a wrote when SHarePoint 2013 was new, as you can see, not much has changed…I have updated a few lines with what I know now that I did not know then, thats it. Please let me know if I missed something.

The recommended approach is to create a GPO with these firewall rules and apply that rule to the SharePoint servers in your farm. Add all of them, best that way to avoid extreme t-shooting in the future.

Another but related recommendation is to configure the Loopback check funktion in Windows server to allow the FQDN’s of your web applications (Use the Loopback check tool).

List of ports used by SharePoint 2013 and its related services.
Reference links at the end.

Protocol Port Usage Comment
TCP 80 http Client to SharePoint web server traffic
(SharePoint – Office Online Server/Office Web Apps communication)
TCP 443 https/ssl Encrypted client to SharePoint web server traffic
(Encrypted SharePoint – Office Online Server/Office Web Apps communication)
TCP 1433 SQL Server default communication port. May be configured to use custom port for increased security
UDP 1434 SQL Server default port used to establish connection May be configured to use custom port for increased security
TCP 445 SQL Server using named pipes When SQL Server is configured to listen for incoming client connections by using named pipes over a NetBIOS session, SQL Server communicates over TCP port 445
TCP 25 SMTP for e-mail integration Cannot in 2016 be configured (Use SMTP ports other than the default (25).)
TCP 16500-16519 Ports used by the search index component Intra-farm only
Inbound rule Added to Windows firewall by SharePoint. (GPO may override this change)
TCP 22233-22236 Ports required for the AppFabric Caching Service Used by the Distributed Cache…
TCP 808 Search – Query processing component
Windows Communication Foundation communication
Search – Query processing component
(WCF)
TCP 32843 Communication between Web servers and service applications http (default) To use custom port, see references section
Inbound rule Added to Windows firewall by SharePoint
TCP 32844 Communication between Web servers and service applications https
Inbound rule Added to Windows firewall by SharePoint
TCP 32845 net.tcp binding: TCP 32845 (only if a third party has implemented this option for a service application)  Custom Service Applications
Inbound rule Added to Windows firewall by SharePoint
TCP 32846 Microsoft SharePoint Foundation User Code Service (for sandbox solutions)  Inbound on all Web Servers
Inbound rule Added to Windows firewall by SharePoint
Outbound on all Web and App servers with service enabled.
TCP 636 User Profile Synchronization Service/Active Directory Import Synchronizing profiles between SharePoint 2016 and AD using SLDAP (Secure LDAP)
TCP 5725 User Profile Synchronization Service Synchronizing profiles between SharePoint 2016 and Active Directory Domain Services (AD DS)
TCP + UDP 389 User Profile Synchronization Service LDAP Service
TCP + UDP 88 User Profile Synchronization Service Kerberos
TCP + UDP 53 User Profile Synchronization Service DNS
UDP 464 User Profile Service Kerberos change password
TCP 809 Office Online Server/Office Web Apps Office Online Server/Office Web Apps intra-farm communication.

References:

Security for SharePoint Server 2016
https://technet.microsoft.com/en-us/library/mt683473(v=office.16).aspx

TCP/IP Ports of SharePoint 2013
https://blog.blksthl.com/2013/02/21/tcpip-ports-of-sharepoint-2013/

 


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Enjoy!

Regards

Twitter | Technet Profile | LinkedIn

How to enable Ping in Windows Server 2012



Updated 2013-02-04 – Added link menu and corrected PowerShell command syntax

This is just a quick guide to enabling a server to respond to ping, the default setting in Windows Server 2012 is to not respond. This is how you do it:

The exact same steps apply to Windows Server 2012 R2

Click to choose your style…
Server2012_Logo_small Enable Ping using the GUI – Graphical User Interface
powershell_logo_small Enable Ping using PowerShell




GUI – Graphical User Interface

1. Open Control Panel, then select System and Security by clicking on that header

2. Select Windows Firewall

3. Advanced Settings

4. In ‘Windows Firewall with Advanced security’ click on ‘Inbound rules’

5. Scroll down to ‘File and Printer sharing (Echo request – ICMPv4-In)

6. Rightclick on the rule and select ‘Enable rule’

Make sure that it turns green

Done, close down the ‘Windows Firewall with Advanced Security’ windows and then the Control panel.
Verify functionality by pinging the servers own IP address from a command or PowerShell prompt.

Done!
Back to top



PowerShell
(This will enable the existing rule exactly as the instruction above does)

Import-Module NetSecurity
Set-NetFirewallRule -DisplayName “File and Printer Sharing (Echo Request – ICMPv4-In)” -enabled True
 
EnablePing

(ABove enables the existing rule, below will create a new rule that allows ICMPv4/Ping and enable it)

Import-Module NetSecurity
New-NetFirewallRule -Name Allow_Ping -DisplayName “Allow Ping”  -Description “Packet Internet Groper ICMPv4” -Protocol ICMPv4 -IcmpType 8 -Enabled True -Profile Any -Action Allow
 
EnablePing2

(For IPv6 Ping you obviously enable the v6 Inbound Rule…)

Thats all there is to it!
Back to top

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Enjoy!

Regards

Twitter | Technet Profile | LinkedIn