All Questions(server)

Looking for advice on what settings to tweak/test and/or what to do to diagnose this problem further as I am not a network expert and there are hundreds of settings on the routers etc.

I have DrayTek Lan-to-Lan VPN IPsec Tunnel setup between 2 sites mainly to manage security on the remote site (CCTV / Alarm / Gate etc).

It all mostly works fine. From the local site (192.168.1.X) I can see all devices on the remote site (172.19.0.X), I can connect to device web interfaces, I can stream camera feeds, control devices etc.

However, one thing that does not work is remote firmware upgrades of devices. For example a camera firmware upgrade which involves a 75MB upload always just fails.

If I open up a port on the router I can remotely update a camera over the internet using the same firmware file so I know that side is all o.k. It just won't work over the IPsec Tunnel and I would like to fix that.

I have since confirmed this is a general "upload" problem by testing large ftp uploads from the same Local Site to Remote Site - they fail (stall) over the VPN.

LOCAL SITE:

WAN: Fibre Internet 
DrayTek Vigor2926
DrayTek Lan to Lan accepts Dial-In:
IPsec Tunnel (IKEv1/IKEv2)
Pre-Shared Key / Medium (AH) AES

REMOTE SITE:

WAN: 3G/4G LTE Modem
DrayTek Vigor2865
DrayTek Lan to Lan Dial-Out:
IPsec Tunnel IKEv2
Pre-Shared Key / Poposal Encryption Auto
IKE Phase 2 Settings: ESP (High) AES256 
Proposal Authentication: All

EDIT 1 - MTU settings on the routers:

The Local Site WAN under Internet Access -> Static or Dynamic IP is set to 1500. The Remote Site WAN under Internet Access -> 3G/4G/5G Modem(DHCP mode) is set to 1500 (the default according to the text there).

EDIT 2 - MTU value from ping test:

I found a ping test script here which I used to find max MTU size as follows:

• From Local Site to Remote Site over VPN: 1500
• From Local Site to Remote Site over WAN: 1500
• From my home to Local Site over WAN: 1492
• From my home to Remote Site over WAN: 1492

EDIT 3 - This DOES seem to be an MTU issue but I still don't understand fully:

The network adaptor on the Local Site has MTU set to 1500 if I temporarily change this to a lower value for example:

sudo ifconfig enp6s0 mtu 1360

Then a test ftp upload works over the VPN. But I would consider this a hacky workaround not a solution.

I looked more closely at router settings and I found under VPN and Remote Access -> IPsec General Setup there is a setting VPN TCP maximum segment size (MSS) for IPsec (IKEv1/IKEv2) which can be between 512 and 1381 and defaults to 1360. I thought maybe this was the answer, and changing the setting to a very low value (512) does affect the ping test (it returns a max MTU value of 1044) but this still has no affect on getting uploads to work over the VPN.

I don't understand why the ping test says the max MTU is 1500 but I have to change the network adaptor MTU setting to get uploads to work and seemingly no changes to settings on the DrayTek router allow uploads to work over it's own IPSec VPN.

So i'm looking at hosting two websites on separate servers For example: Production site on the IIS server: 192.168.0.1 and SpecialApps IIS: 192.168.0.2 which is also the current test server which will eventually go into production.

Currently after countless hours of research, it been suggested that I should install Application Request Routing (ARR), which I had done so on the .2 server

my goal is to be able to go https://test.mycompany.com.au to go into .2 and https://test.mycompany.com.au/prod to go to .1

when the user go https://test.mycompany.com.au/prod, need to redirect to https://mycompany.com.au which is the production url that is hosted on .1

Having issues trying to get the URL Rewrite code pattern working

Is this even viable?

I want to use dd under linux to make a backup image of my disk. With sata devices there is a /dev/sda for the disk, and /dev/sdaX for each partition.

But with this nvme I see /dev/nvme0, /dev/nvme0n1, and /dev/nbme0n1pX. That last is clearly the partitions, but which of the former should I use to backup my disk? (nvme0 vs nvme0n1).

What is the purpose of having 2 devices representing the disk?

And when I restore the disk, to which device do I write?

We just converted 4 of our AD security groups to mail-enabled. These groups grant access to different areas of an application and we occasionally need to notify the users of planned outages, unexpected outages, etc, of that application. This is why we converted those groups to mail enabled.

However, some of our users are in multiple groups. I'd like to send one email to all 4 of these groups to notify the users. If I do this, how many emails will the members who exist in >1 group receive?

For example:

Member A is in group 1 and group 2. I send an email to where both groups are in the To field. How many emails will Member A receive?

I would typically test this myself but creating a new security group requires a CR and whatnot from the administration team, so I'm hoping someone can just give me the answer.

In Intune, Entra, how can I find and delete orphaned devices, where the primary UPN is deleted? I also need to remove them from Autopilot. Has someone got a powershell script?