What is the biggest attack in GBPS you stopped

[tim.mcmanus]

Yes, not all CPU will be busy, but all CPUs allocated to a VM must be present for the VM to compute.

For example, if you have 16 cores and 12 are busy, and a VM with 8 cores comes along, it will wait until 8 cores are available to process data.  It cannot use the 4 cores available in the example above, it must find 8 available cores and then compute whether or not it needs all 8 cores.  It's an allocation model.  So CPU contention can create excessive wait times while CPU utilization is very low.

[Supermule]

Yes but it didnt :)

I can reissue 8 cores and test again. :)

[Supermule]

Even with 8 cores it doesnt get past 0.33 %CSTP :)

[Supermule]

I rebooted the server behind that receives the traffic while attacking.

Packet loss still occured and then I shut it down completely.

In the end you see the traffic settle in on around 7.5mbit/s and become a straight line.

Then packets begin to flow and CPU4 settles below 100%.

Youtube Video

What you reckon Tim?

[Supermule]

This is the IOPS I see on the storage attached as NFS during an attack.

[tim.mcmanus]

@Supermule:

What you reckon Tim?

I reckon it's going to be very complicated troubleshooting an apparent kernel issue in FreeBSD while it's running on a hypervisor.

[firewalluser]

@tim.mcmanus:

Yes, not all CPU will be busy, but all CPUs allocated to a VM must be present for the VM to compute.

For example, if you have 16 cores and 12 are busy, and a VM with 8 cores comes along, it will wait until 8 cores are available to process data.  It cannot use the 4 cores available in the example above, it must find 8 available cores and then compute whether or not it needs all 8 cores.  It's an allocation model.  So CPU contention can create excessive wait times while CPU utilization is very low.

Correct. https://communities.vmware.com/message/2275523

IF anything you'd be better off reducing the number of cores a VM needs as minimum rather than give it the most it can use, as the overhead switching or timeslicing at the host (ESXi) level can be further reduced just like sometimes its faster to run software single threaded on a single core than a multithread app across all cores, as the latter introduces more locks & overheads at the sw level as well as the cpu level not to mention having to share the bus to devices like the hw, nics or ram.

Besides running alot of OS tended to be faster as a VM instead of bare metal, eg I can install W7x32 as a VM in just 6mins 23 seconds from hitting play on the VM for the first time, various reboots, assigning username & password, updates settings all the way to being on the desktop for the very first time. I might be able to shave a few more seconds off by not running other VM's at the same time, but I cant do that time installing W7x32 on the same bare metal machine which is a testament to VMware.

[tim.mcmanus]

@Supermule:

Wait, %WAIT:

• This value represents the percentage of time the virtual machine was waiting for some VMkernel activity to complete (such as I/O) before it can continue.

• If the virtual machine is unresponsive and the %WAIT value is proportionally higher than %RUN, %RDY, and %CSTP, then it can indicate that the world is waiting for a VMkernel operation to complete.

• You may observe that the %SYS is proportionally higher than %RUN. %SYS represents the percentage of time spent by system services on behalf of the virtual machine.

• A high %WAIT value can be a result of a poorly performing storage device where the virtual machine is residing. If you are experiencing storage latency and timeouts, it may trigger these types of symptoms across multiple virtual machines residing in the same LUN, volume, or array depending on the scale of the storage performance issue.

• A high %WAIT value can also be triggered by latency to any device in the virtual machine configuration. This can include but is not limited to serial pass-through devices, parallel pass-through parallel , and USB devices. If the device suddenly stops functioning or responding, it can result in these symptoms. A common cause for a high %WAIT value is ISO files that are left mounted in the virtual machine accidentally are either deleted or moved to an alternate location. For more information, see Deleting a datastore from the Datastore inventory results in the error: device or resource busy (1015791).

• If there does not appear to be any backing storage or networking infrastructure issue, it may be pertinent to crash the virtual machine to collect additional diagnostic information.

You had an 800%-900% wait time in the video you posted.  Holy crap, that's insane!  See the part above that talks about latency.  This is a smoking gun!

I've been very consistent when I've said that testing pfSense on a VM isn't going to give you tangible data because you'll also need to troubleshoot the hypervisor layer at the same time.

Please, please, please stop wasting your time testing this issue on a hypervisor.  Put pfSense on bare metal and test it there.

[dennypage]

I couldn't agree more.

@tim.mcmanus:

Please, please, please stop wasting your time testing this issue on a hypervisor.  Put pfSense on bare metal and test it there.

[NOYB]

@dennypage:

I couldn't agree more.

@tim.mcmanus:

Please, please, please stop wasting your time testing this issue on a hypervisor.  Put pfSense on bare metal and test it there.

Ditto

Too much shot-gunning going on in this effort instead of a methodical systematic approach.

Begin with minimalist install / config (bare metal, no packages, no services, etc.) and work up to point of failure.

If the minimalist install / config fails then go back even further to either earlier pfSense versions, or better yet to FreeBSD itself until the issue does not exist.  Then systematically move forward  adding to that config until the issue appears.

[Supermule]

Jun 4 09:28:36    check_reload_status: Reloading filter
Jun 4 09:28:36    check_reload_status: Restarting OpenVPN tunnels/interfaces
Jun 4 09:28:36    check_reload_status: Restarting ipsec tunnels
Jun 4 09:28:36    check_reload_status: updating dyndns Yousee
Jun 4 09:06:36    check_reload_status: Reloading filter
Jun 4 09:06:33    check_reload_status: Syncing firewall
Jun 4 09:05:08    check_reload_status: Reloading filter
Jun 4 09:05:06    check_reload_status: Syncing firewall
Jun 4 09:01:12    kernel: em0: promiscuous mode enabled

When this happens the firewall encounters packetloss.

Disabling promiscious mode on em0 and em1 solves it and makes it endure.

Running CRON job every 60 seconds will make you survive a SYN flood.

[firewalluser]

So whats the number of CPU's and cores available?

What VM's are you running and how many CPU's/Cores do each need as a minimum?

Possibly the best way to visualise this is a bit like a game of tetris but various sized horizontal sized blocks which are your minimum core requirements for the VM OS.

If you have a 4 core baremetal then your Tetris game is just four blocks wide, if its a 2 cpu, 8 core, the your Tetris game is 16 blocks wide.

When the blocks reach the base, thats your hypervisor's timeslice to work on the physical cpu's/cores.

Your task is to try and fit as many horizontal blocks representing the core requirement of your VM OS's to use up all the space. This is why its best to run VM's as a minimum sized cores/vCPU's in most cases.

eg say you have 4 OS's and 1 cpu/4 cores.
OS1 needs 2 cores min but can use 10 cores max.
OS2 needs 4 cores min but can use 8 cores max
OS3 needs 1 core min but can use 4 cores max
OS4 needs 1 core min but can use 2 cores max.

Whats the most efficient way to set these OS's up as VM's in order to maximise the time slices for each?

If you went:
OS1 4cores
OS2 4cores
OS3 4cores
OS4 2cores

When ever OS4 had its time slice you waste 2 physical cores.

This approach would also make for a clunky setup because if any OS needs to talk to another, then you have no two OS's running in the same time slice to communicate with each other, they will all have to wait 4 time slices to before they can get back and process their stuff.

If you went
OS1 2cores
OS2 4cores
OS3 1cores
OS4 1cores

Then OS3 & OS4 can run when ever OS1 runs so you now have a "block" where you in effect have OS1, OS3 and OS4 that can operate in one timeslice and OS2 can operate in another timeslice. ESXi only has to swap between two different blocks of OS's (OS1,OS3 & OS4) and OS2, which makes for a more responsive setup as the OS's in the first block can communicate between themselves if need be in teh same timeslice and so the only extra wait time for any communication is swapping from block 1(OS1, OS3 & OS4) to block 2(OS2) which is running OS2.

Does that make sense and easier to understand?

Its more complicated than that because next you have RAM requirements to consider as well, but a similar principle exists, ie if you err towards less ram, ESXi doesnt have to spend time loading and unloading ram for each VM running in the timeslice. Its best to have the ram requirements for each VM' fit within the physical ram.

So if you take the 2nd example above.

OS1 2cores
OS2 4cores
OS3 1cores
OS4 1cores

You have lets say 32Gb of physical ram.

OS1 can use 8GB to 32GB
OS2 can use 4GB to 16GB
OS3 can use 2GB to 4GB
OS3 can use 4GB to 16GB

OS1 2cores/32GB
OS2 4cores/16GB
OS3 1cores/4GB
OS4 1cores/16GB

Then even though the first block(OS1,OS3&OS4) can share the physical CPU's, they cant share the physical as you would need 42GB of physical ram.

But if you went

OS1 2cores/16GB
OS2 4cores/16GB
OS3 1cores/4GB
OS4 1cores/8GB

Then the first block (OS1,OS3&OS4) can share the physical ram as the total amount is 32GB, and the 2nd block(OS2) will use 16Gb with 16Gb going spare doing nothing.

If you notice I gave OS1 16GB, this is because even though OS4 can also use 16GB its only got 1 core.

However you then also need to look at what the tasks are that are going to be running on each VM.

Databases love ram, the more ram you have the more you can load the DB into ram already sorted into the most popular views that users use the most.

MS Exchange is similar ie its just a big DB but it offloads alot of its work to the workstation so Outlook will often have a copy of what is stored in Exchange so outlook only has to access the local disk, but Exchange will have lots of connections like keep-alive open for smart phones so that it can "push" emails & other things to the phones.

Webservers depends on what they are doing, some maybe front for DB's running on the same VM or maybe not, but hopefully that will give you a better overview of whats going on at a lower level.  :)

[Supermule]

I have divided the 2 running VM's here at home on 2 different sockets with 4 cores each.

Didnt matter at all until I ran the cron job disabling promiscous mode.

Its in the reject state on the hypervisor Vswitch allready….

[lowprofile]

@dennypage:

I couldn't agree more.

@tim.mcmanus:

Please, please, please stop wasting your time testing this issue on a hypervisor.  Put pfSense on bare metal and test it there.

IT ISN'T BETTER ON BAREMETAL. Problem still exist. I tried several times on my bare metal supermicro.
Read the thread and the other threads again. You will see the history.

• i am though not using pfsense anymore. So i can no more test

[firewalluser]

@Supermule:

I have divided the 2 running VM's here at home on 2 different sockets with 4 cores each.

Didnt matter at all until I ran the cron job disabling promiscous mode.

Its in the reject state on the hypervisor Vswitch allready….

You know about promiscuous mode can mess up some nics? You'll see this note in the packet capture amongst other places.

What are your System:Advanced:Networking, Networking tab, Network checkboxes set to?

How did you install the VM?
Did you install from iso on the ESXi server or setup pfsense on a different bare metal/VMware host like VMware workstation, cloned it then moved it to the ESXi server in question?

pfsense is one vm, whats the other VM?

[Supermule]

1: Yes.

2: Picture attached.

3: From ISO directly on to the ESXi

4: Homeserver (Windows 2008 R2)

[Supermule]

Disabling Apinger so the interface doesnt get restarted all the time during an attack.

IN the traffic graph you are able to see the drop in traffic after the ifconfig em0 -promisc reload in cron.

That makes the firewall come alive and start routing packets again.

I have attached the screenshot before and after the reload as running top -HSP


[firewalluser]

In your pic, the first ticked checkbox is normally unticked for default.

Have you been toggling these?
If so notice any difference?

Have you been through the pfsense 2 on VMware ESXI 5.5 pfsense docs to check settings?

When you run the DDOS is homeserver running as well? I know thats your aim ultimately, but does pfsense perform better without it running?

Do you have the Sata driver installed? Check out airvpn.org/topic/11847-pfsense-performance-configs-on-esxi-vmware/
that might be a lead?

Hows your management channel setup?

Apologies if you have posted your VM settings, I dont recall seeing them, but if you havent can you post them as its a case of trying to see if thats been setup properly and not causing the problem which is making pfsense fail under the ddos. We cant rule the ESXi VM guest settings out just yet imo.

Got to go out for a couple hours now, but its definately worth going back over all the settings.

Have you even setup a basic pfsense with minimal settings, no packages, no config changes other than ip address changes for nics to see how that copes with the DDOS?

I think this is a back to basics moment like others have suggested, although I know baremetal isnt an option, but making sure the guest is configured right and then installing a basic pfsense installation would be my next move. If that handles the DDOS, I'd pull the XML backups and compare differences as its easy to miss something when toggling various settings in situations like this.

Good luck!  :)

@Supermule:

Disabling Apinger so the interface doesnt get restarted all the time during an attack.

IN the traffic graph you are able to see the drop in traffic after the ifconfig em0 -promisc reload in cron.

That makes the firewall come alive and start routing packets again.

I have attached the screenshot before and after the reload as running top -HSP

Although I could only get 2.42Mbps, apinger was still getting out for me as its only got to ping some ip addresses a couple hops away unlike your ddos traffic which is coming from all around the world and thus further away. The network infrastructure would let ip addresses closer to me get through as the bottle necks would be further away.

[Supermule]

@firewalluser:

In your pic, the first ticked checkbox is normally unticked for default.

Have you been toggling these?
If so notice any difference?

Not seen any difference at all.

Have you been through the pfsense 2 on VMware ESXI 5.5 pfsense docs to check settings?

Yes

When you run the DDOS is homeserver running as well?

Yes.

I know thats your aim ultimately, but does pfsense perform better without it running?

No difference.

Do you have the Sata driver installed?

No running on a scsi controller.

Hows your management channel setup?

Not understood. Using vsphere client, console and Putty.

Apologies if you have posted your VM settings, I dont recall seeing them, but if you havent can you post them as its a case of trying to see if thats been setup properly and not causing the problem which is making pfsense fail under the ddos. We cant rule the ESXi VM guest settings out just yet imo.

Youtube Video

Got to go out for a couple hours now, but its definately worth going back over all the settings.

Enjoy.

Have you even setup a basic pfsense with minimal settings, no packages, no config changes other than ip address changes for nics to see how that copes with the DDOS?

Yes. It didnt do very well.

I think this is a back to basics moment like others have suggested, although I know baremetal isnt an option, but making sure the guest is configured right and then installing a basic pfsense installation would be my next move. If that handles the DDOS, I'd pull the XML backups and compare differences as its easy to miss something when toggling various settings in situations like this.

I haves asked Tim and Almabes if they have any available. Apparently it does make any difference.

Good luck!  :)

Thanks :)

[Supermule]

Any way to monitor cron jobs in real time??

Tried crontab -l but it says it cannot find any for the user root…

Tried changing it to crontab - admin -l but that doesnt work either.

I want to have a console running so I can see specifically when cron is run since it doesnt say anything in the system logs.

This is a real bitch to trouble shoot internally.................................