ZFS snapshots are also usefull, if you do one before you screw up.

Currently I have 2.4.2 installed, i might have had another issue prior. Now i have another issue, basically i'm capped at 100Mbps whereas the DSL service is 250Mbps Up & Down. My NICs are both gigabit so i'm wondering what is causing the loss of performance? Could it be the PCs specs? Duo Core.. Thanks again for all your help :)

@Jordan10: @bimmerdriver: @Jordan10: The pc is running Windows Server 2016, sorry i should of mentioned that before, it also meets all the hardware requirements needed for pfsense apart from the dual nics which is why I've ordered another nic today :) Okay, that's another matter. I'll explain how I have my system set up and you can see if that makes sense for you. My system has 3 nics, wan, lan and other. The wan and lan nics are externally connected to the bridged port on the modem and and a physical ethernet switch, respectively. Internally, they are connected to virtual switches. The lan switch is set to allow the management operating system to share the lan nic. The wan nic is also set to enable source mirroring so I can connect a virtual pc to the switch running wireshark. With this configuration, I can have multiple pfsenses connected to the wan switch and I can even have a completely virtual lan and virtual clients. I can also have physical clients on the physical lan switch. I've been using this configuration for several years and it works well. The "other" nic is connected to a lan port on the modem so I can access the modem GUI from the hyper-v server. (I bumped up the routing metric on this interface so no traffic will exit.) Feel free to ask more questions if you have any. Thanks for the info, so from what you've said wan and lan nics can go to the ethernet ports on my router and i can still let the router handle dhcp and the wan connection? Or do i need to have a physical switch as well in order to do this? Obviously I'll have the wan and lan nics connected to the virtual switches running in hyper-v as well.  New nic is arriving tomorrow so hopefully I'll be able to access the web configurator again at least which is what I'm struggling to do at the moment even with the existing nic i have which is set up with pfsense too  :-\ I attached a picture. Maybe it helps. The AP, along with pcs and other devices are on the lan switch.  

I'm saying that, barring any problems unrelated to the 7551, any upgrade will work on it. In other words: If the upgrade failed, it wasn't because it was run on a 7551. The only specific failure that affects the 7551 is a fresh installation of 2.4.x, which can be worked around as mentioned in the wiki. So if your upgrade failed, post about that instead with more detail because it doesn't have anything to do with the hardware.

OK, Thanks for you insight!!  8)

I came upon that very thread. I left it for over 2 hours without success. BUT, the system is not frozen. I came back after 2 hours, and short-pressed the power button - and the "Syncing vnodes" message came up and the system powered off gracefully. If it is indeed hanging because of pfBlocker (which incidentally, I do have installed), then there should be some log entries somewhere surely? Is there some way to access the "console" mid boot to see what is going on? I'm using the "vga" version of the image so I don't think the info is going to the serial console or anything. Basically after I restored my config file the pfsense became a brick. No ping to the LAN interface at all, no boot, no response from keyboard if I press enter or anything (but numlock works). The only fix was to reinstall (or to manually edit the config.xml I suppose but that doesn't fix the underlying problem).

@luke1018: …. there are errors .... Bad news  ;) Billion exist already - and people report nearly daily new ones. Next time, take some more time to compose your question, and add the error with all it's details.

It's normal that you don't see the card anymore in windows after writing the pfSense install image on it. MS Windows has no clue of the BSD partitioning scheme or the UFS filesystem used.

@Thierry69: Doesn't seems to want to boot on the USB stick … Thx You have to make some changes in BIOS. https://forum.pfsense.org/index.php?topic=43574.0 http://www.triebwerk23.de/joomla/index.php/firewalls/watchguard-xtm-5-xtm-505-515-525-545-pfsense-64-bit

I finaly upgrade to 4.2 with command shell login to the box with ssh (user admin pw : ….) go to command shell type command : "pfSense-upgrade -d" it take a long time and finaly the upgrade is done.

Oh right, id followed all the guides and it'd been running for years ok (freebsd 64bit). Do you have any suggestions on what may need looked at? Will try and mount the vmdk to grab that config as a last resort

So I reinstalled pfSense from 2.4.2-RC snapshot (20171117) and used a different boot drive (some spare WD Red spinning NAS drive). After some time I experienced a first panic, "Fatal trap 1: privileged instruction fault while in kernel mode". I applied options mentioned by @Birke, and rebooted the system. Sysctl complained that all hw.igb.* tunables are read only, but the system ran without a crash for over 30h. Not sure if these options helped of if I had luck. To get a better use of my systems CPU I enabled PowerD (Hidaptive) and AES-NI acceleration for crypto. Some time after that I experienced another crash, similar to previous one + mentioned "Fatal trap 12: page fault while in kernel mode". At this point I have no idea where does the problem come from. I contacted another forum member that owns this motherboard and he told me that his system runs stable without any tunable changes :(

That doesn't happen here when choosing the auto options. It sounds to me like it either went into the manual install or something was wrong with the existing disk layout that auto couldn't handle.

So, apply https://forum.pfsense.org/index.php?topic=138656.msg761867#msg761867  (first line) to have a fast, positive result ;)

@Jed: Appartently something is wrong with the DNS entry for pkg.pfsense.org Nothing is wrong. SRV records do not work that way. https://forum.pfsense.org/index.php?topic=130708.msg719850#msg719850