pfSense on OVH VPS

12:45 pm Uncategorized

I have a unique situation where my ISP has me behind 2 NAT routers and applying to have a port forward always turns into a big problem. I have a need for some public facing services that I wish to host in my home lab. Originally I setup an OVH VPS using the OpenVPN Access Server and just connected to it with some port forwards. However, I was really missing some of the advanced features and GUI of pfSense. FreeBSD is not an option for an OVH VPS so I started down the path of trying to figure out how to get this to work.

First you must start out with a Ubuntu VPS. For this purpose I chose Ubuntu 18.04. I did a fresh install.

Once your VPS is ready refer to the email from OVH for your root password. The rest of this work will be done in the KVM. It is easier to copy and paste in a SSH session but the system isn’t accessible the entire time so the KVM is easier at this point.

Document your default gateway

root@vps:# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         54.39.176.1     0.0.0.0         UG    0      0        0 ens3
54.39.176.1     0.0.0.0         255.255.255.255 UH    0      0        0 ens3

In this example my default gateway is 54.39.176.1.

Prepare grub to boot mfsbsd into RAM.

root@vps:# nano /etc/default/grub
#GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=5

root@vps:# nano /etc/default/grub.d/50-cloudimg-settings.cfg
GRUB_TIMEOUT=5

root@vps:# apt install grub-imageboot -y
root@vps:# mkdir /boot/images
root@vps:# cd /boot/images
root@vps:# wget https://mfsbsd.vx.sk/files/images/12/amd64/mfsbsd-se-12.0-RELEASE-amd64.img
root@vps:# update-grub2
root@vps:# reboot

I previously tried to install pfSense from the ISO this way but it always fails as it is looking for the CD. mfsbsd is designed to run from PXE in RAM so this was a working solution.

Boot into mfsbsd

In the grub boot menu select “Bootable Floppy Image: mfsbsd-se-12.0-RELEASE-amd64” then wait. It takes a bit for it to start. Let the system boot into Multi User.

username: root
password: mfsroot

document your interface name

root@mfsbsd:# ifconfig
vtnet0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
etc....

vtnet0 should be your interface name. Routing doesn’t work automatically because the gateway is in a different network than your DHCP assigned address. You must manually assign a route to the interface then add the default gateway.

root@mfsbsd:# /sbin/route add -host 54.39.176.1 -iface vtnet0
root@mfsbsd:# /sbin/route add default 54.39.176.1

Download needed software

root@mfsbsd:# pkg install wget
root@mfsbsd:# cd /tmp
root@mfsbsd:# wget -O - https://nyifiles.pfsense.org/mirror/downloads/pfSense-CE-2.4.4-RELEASE-p1-amd64.iso.gz --no-check-certificate | gunzip -c > pfsense.iso

You may need to adjust your pfSense ISO download URL. You have to use the –no-check-certificate because we don’t have trusted CA’s in the live mfsbsd.

Mount ISO and run installer from chroot

root@mfsbsd:# mdconfig -a -t vnode -f /tmp/pfsense.iso
root@mfsbsd:# mount -t cd9660 /dev/md1 /cdrom

root@mfsbsd:# mount -t devfs devfs /cdrom/dev
root@mfsbsd:# mount -t tmpfs tmpfs /cdrom/tmp

root@mfsbsd:# chroot /cdrom
root@mfsbsd:# /usr/sbin/bsdinstall

Welcome to the pfSense Installer

Perform a regular install. I chose UFS and left the installer to the defaults.

Reboot when done. The pfSense CLI wizard will start automatically.

DO VLANs need to be setup first? N
Type vtnet0 as your WAN interface.
LAN interface should be empty.
Press 8 and [enter] to access the pfSense Shell.

[2.4.4-RELEASE][admin@pfSense.localdomain]/root: /sbin/route add -host 54.39.176.1 -iface vtnet0
[2.4.4-RELEASE][admin@pfSense.localdomain]/root: /sbin/route add default 54.39.176.1
[2.4.4-RELEASE][admin@pfSense.localdomain]/root: exit

Document your WAN IP address from the pfSense Welcome Screen.

Login to pfSense Web GUI and install Shellcmd

https://a.b.c.d
username: admin
password: pfsense

Immediately change your password. Its a warning banner at the top.

Click on System > Package Manager, then Available Packages.
Find Shellcmd and click on +Install

Click on Services > Shellcmd
Click +Add

command:

/sbin/route add -host 54.39.176.1 -iface vtnet0 && /sbin/route add default 54.39.176.1

Shellcmd Type:

shellcmd

Use the same command and +Add another command and select ”
afterfilterchangeshellcmd” as the Shellcmd Type.

Now when you reboot your pfSense will get its IP from DHCP and setup routing automatically for you. Even when you reload your filter.

Conclusion

At this point I now have a public IP address on a pfSense firewall. From here I was able to setup OpenVPN and setup NAT Port Forwarding to my home lab.

One Response

  1. ben Says:

    Thank you, that was just what I needed!

    At the final step, I think I achieved the same result through the GUI by going to System -> Routing and adding a gateway on the WAN interface. Needed to select Advanced -> Use non-local gateway to allow a gateway outside the local subnet.

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