What is the biggest attack in GBPS you stopped
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After fiddling with some settings under system ->tunables i got it to distribute the load better so to speak.
No 100% cpu core and then it works fine.
So what settings did you add or change?
@mer:
I'm gonna try and find something other than syslog to report back the state of the machine, perhaps security onion which I need to check out still, but I'm keen to find something that can control parts of the fw depending on some situations occurring, ie if I get a ddos, I can resave the WAN interface and get assigned a new ip address as one measure I'd like to implement. I could knock something up but its also a case of getting the data out of pfsense over and above syslog data that would make it even more useful.
Still lots to learn.
For quick simple stats, man vmstat man procstat
Thanks, however whats the best way to get all/as much data as possible including rule matches out of pfsense, I've got to check out security onion but if there are other ways I'm all ears. I saw nagios earlier which might be interesting to see what and how it gets data out of pfsense and other platforms, but theres things it doesnt do which I'd like.
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After fiddling with some settings under system ->tunables i got it to distribute the load better so to speak.
No 100% cpu core and then it works fine.
So what settings did you add or change?
@mer:
I'm gonna try and find something other than syslog to report back the state of the machine, perhaps security onion which I need to check out still, but I'm keen to find something that can control parts of the fw depending on some situations occurring, ie if I get a ddos, I can resave the WAN interface and get assigned a new ip address as one measure I'd like to implement. I could knock something up but its also a case of getting the data out of pfsense over and above syslog data that would make it even more useful.
Still lots to learn.
For quick simple stats, man vmstat man procstat
Thanks, however whats the best way to get all/as much data as possible including rule matches out of pfsense, I've got to check out security onion but if there are other ways I'm all ears. I saw nagios earlier which might be interesting to see what and how it gets data out of pfsense and other platforms, but theres things it doesnt do which I'd like.
I have Security Onion set it, and for these attacks, the best IMHO is Wireshark. It'll do more for you in the near term. SO is a good suite of tools, but it's not for the faint of heart. It requires work to set it up properly and to ensure rules are updated. Also, you'll need a decent sized hard drive because it captures and logs every packet. The more storage, the more historical. So also won't get anything out of pfSense, in fact it won't talk to it unless you integrate snort and barnyard from one box to the other.
nagios is also not for the faint of heart. I went with OpenNMS because it's easy to set up, and I already know SNMP. If you want any more granularity into the box, you'll have to go with an agent-based monitoring tool or something like vRealize Hyperic for your VMs, and that ain't cheap.
dtrace is the best place to start if you want to get granular information out of pfSense. It's a FreeBSD debugging tool, and that's exactly what needs to be done to determine the root cause. And there is a somewhat steep learning curve there if you've never written or debugged your own complied code. Not impossible, but it will take time.
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This is what I have added so far. Its not perfect but way better than out of the box.
Changing the maxlen queue did good in regards to distributing load, but it seems it doesnt survive a reboot.
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Those are most likely sysctls, worst case is you can put them in /etc/sysctl.conf to survive a reboot.
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@mer:
Those are most likely sysctls, worst case is you can put them in /etc/sysctl.conf to survive a reboot.
Which if sysctl.conf does need to be edited, then this thread https://forum.pfsense.org/index.php?topic=81174.0 or this thread https://forum.pfsense.org/index.php?topic=94511.0 can help those changes survive the reboot because even though the threads discuss syslog.conf and system.inc files, the principle will be the same, ie the filename is not so important but the methods to keep the changes is.
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For you to enjoy
top -HSP
top -asSHz1
Are you running pfSense in a hypervisor? If so, you're dealing with an additional abstraction layer. What does the hypervisor kernel look like? You should, I think, be able to run top by sshing into ESXi. However, the point is that running it on a hypervisor may mask r present issues differently than running on bare metal.
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With esxtop running
http://youtu.be/_dimZ1_DO_o
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With esxtop running
http://youtu.be/_dimZ1_DO_o
Your wait time is insane on the hypervisor.
The way ESXi works is that it needs all 8 cores free before it will allow the CPU in your VM to process data. So if you've over-subcribed CPUs, your wait time goes through the roof while the VM waits for all 8 cores to become free to the VM; hence it's waiting for free cores to process data.
You can impair a VM considerably because of wait time and CPU availability. It's one of the reasons why Oracle wants you to test their products on iron and will not support you if you're not using their hypervisor. If you aren't aware of how wait times work at the hypervisor level, it'll bite you in the ass.
In this case perhaps the hypervisor kernel is using multiple cores on the CPU to accept data from the NIC. As you hammer that NIC, CPU wait times go up because the hypervisor kernel has a higher priority than your VM, so your VM is left waiting.
When we tested FreeBSD and CentOS, my hypervisor was crushed. It wasn't readily apparent if the issue was with the hypervisor or the VM, but I believe it was a combination of the two.
If you can, remove the hypervisor layer so all you have to deal with is the hardware and BIOS.
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Its accumulated idle time. Not the actual VM waiting…
Run, %RUN:
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This value represents the percentage of absolute time the virtual machine was running on the system.
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If the virtual machine is unresponsive, %RUN may indicate that the guest operating system is busy conducting an operation.
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When %RUN is near zero and the virtual machine is unresponsive, it means that the virtual machine is idle, blocked on an operation, or is not scheduled due to resource contention. Look at other values (%WAIT, %RDY, and %CSTP) to identify resource contention.
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When %RUN is near the value of the number of vCPUS x 100%, it means that all vCPUs in the virtual machine are busy. This is an indicator that the guest operating system may be stuck in a operational loop. To investigate this issue further, you may need to engage the appropriate operating system vendor for assistance in identifying why the guest operating system is using all of the CPU resources.
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If you have engaged the guest operating system vendor, and they have determined that the issue is caused by the VMware Tools or the virtual machine hardware, it may be pertinent to suspend the virtual machine to collect additional diagnostic information.
Wait, %WAIT:
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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.
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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.
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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.
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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.
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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).
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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.
Ready, %RDY:
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This value represents the percentage of time that the virtual machine is ready to execute commands, but has not yet been scheduled for CPU time due to contention with other virtual machines.
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Compare against the Max-Limited, %MLMTD value. This represents the amount of time that the virtual machine was ready to execute, but has not been scheduled for CPU time because the VMkernel deliberately constrained it. For more information, see the Managing Resource Pools section of the vSphere Monitoring and Performance Guide or Resource Management Guide.
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If the virtual machine is unresponsive or very slow and %MLMTD is low, it may indicate that the ESX host has limited CPU time to schedule for this virtual machine.
Co-stop, %CSTP:
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This value represents the percentage of time that the virtual machine is ready to execute commands but that it is waiting for the availability of multiple CPUs as the virtual machine is configured to use multiple vCPUs.
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If the virtual machine is unresponsive and %CSTP is proportionally high compared to %RUN, it may indicate that the ESX host has limited CPU resources, simultaneously co-schedule all vCPUs in this virtual machine.
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Review the usage of virtual machines running with multiple vCPUs on this host. For example, a virtual machine with four vCPUs may need to schedule 4 pCPUs to do an operation. If there are multiple virtual machines configured in this way, it may lead to CPU contention and resource starvation.
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Its accumulated idle time. Not the actual VM waiting…
I disagree. Try dropping the cores down to two and see if that wait time drops.
I actually had a conversation with VMware about this yesterday. Our SQL farm is getting crushed by wait time due to CPU over-subscription. We're about to start a VM right-sizing exercise to address the issue.
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%RUN = 290.51 (could be 400%) so it means not all CPU's are busy
%WAIT=408.70 (Could be my NAS at home where the VMresides, Synology 1813+)
%RDY=0.18 (% time a vCPU was ready to be scheduled on a physical processor but couldn’t due to processor contention. Threshold: 10% per vCPU)
%MLMTD=0.00 (% time the VM was ready to run but wasn’t scheduled because it would violate the CPU Limit set. Threshold: 0%)
%CTSP=0.00% (% time a vCPU in an SMP virtual machine is “stopped” from executing, so that another vCPU in the same virtual machine could be run to “catch-up” and make sure the skew between the two virtual processors doesn’t grow too large. Threshold: 3%)It doesnt indicate that the hypervisor subsystem suffers in any way, but storage wise(maybe).
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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.
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Yes but it didnt :)
I can reissue 8 cores and test again. :)
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Even with 8 cores it doesnt get past 0.33 %CSTP :)
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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%.
What you reckon Tim?
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This is the IOPS I see on the storage attached as NFS during an attack.
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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.
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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.
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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.
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