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Does this produce any output?

No. (I had to make it a one-liner because it complained about an Unmatched '"' but that shouldn't matter, I suppose.)

Regarding your side question, the options allow for either having concurrent users (across multiple MACs), or not. If you don't allow them, previous sessions will automatically be killed. You can split this functionality up by splitting into zones if your architecture allows. However, this shouldn't be relevant for the problem you're seeing, as multiple sessions bound to the same user/MAC should not exist in any case.

We need to be able to hand out vouchers that can be used by multiple users during certain events and sadly, the "one session per user" restriction would apply to vouchers, too.

I would assume there's no way to treat users and vouchers differently. Is that correct?

Splitting up zones is indeed what we're currently considering. I guess the only way to achieve this would be two different CP instances - one for users and one for vouchers - on two different WiFi networks and asking the user to pick the correct WiFi. We want to avoid this, but maybe we won't have much of a choice. Doing so and limiting sessions to one per user would of course solve our original problem, but as you said, multiple sessions for a single MAC shouldn't exist anyway, so you might just treat this part as a bug report. ;-)

We have a rather big CP setup (few hundred sessions) and occasionally a single session shows up multiple times (see attached screenshot). This is a bit of a nuisance (though not a big problem) as we want to limit the number of devices per user and our monitoring system shows a warning if the number of sessions per user exceeds a certain limit.

At the moment, we don't really know how the problem can be triggered. Right now we have ~400 sessions and only one shows up multiple times.

Side question:

Is there a way to limit the number of concurrent CP sessions per user - for example by automatically killing any previous sessions once a new one is started? Ideally, this should *not* apply to vouchers.

Hi,

we're trying to add a second WAN-gateway as failover if the first one goes down. Our main gateway uses a static IP configuration, the backup is configured via DHCP. We already successfully configured a manual failover: Our main gateway was down and we got our backup up and running. Currently both gateways are up though only one is being used, which is fine. Our next step is setting up an automatic failover, so we try to set up gateway monitoring - which is where the trouble starts...

We added an IP for gateway monitoring for each gateway and both gateways are being shown as "Up" as expected. As soon as we physically unplug the backup gateway, this is shown as being down, so everything's still fine. Plugging the backup gateway back in causes the it to be shown as "Up" - which is fine - but at the same time the main gateway is being shown as "Down" - even though it is still working.

Since I assume that automatic failover depends on reliable gateway monitoring, I think I need to fix that monitoring issue before setting it up. So what can I do to debug this issue?

Regards
Thomas

@thomasE

Great that you finally got to the bottom of this.
Did you return the dec4280 to Deciso or did you find a job it can handle?

Returning the appliance wouldn't have solved our problem as we'd still have OPNsense running on a single, quite capable server that should be put to better use elsewhere. Under heavy network load we're already experiencing some issues and as bandwidth increases, this will get worse eventually. I'm not even talking about the consequences of building a CARP cluster for redundancy. ;-)

We're currently working on a network redesign migrating a significant part of the interfaces to switches and route them via a transfer network to the OPNsense. That way we can reduce the number of interfaces on the OPNsense from around 300 to about 20. Fortunately, our switches are able to handle this - we've checked that already. ;-) Lots of work ahead, but at least it will simplify setting up CARP...

As a customer with an official Deciso appliance I would move this discussion from the community forum to an equally official support case.

We're in constant communication with our hardware vendor (who in turn talks with Deciso) and we finally got some answers:

OPNsense will eventually run into performance issues once the number of interfaces reaches three digits. That's the core of the problem and it fits perfectly into what we observed. It has nothing to do with NICs or any other hardware/driver issues, the amount of traffic, open CP sessions or whatsoever. Using more powerful hardware will - likely only up to a point - mitigate the problem, but there's no way it can actually solve it. It's a software design issue - OPNsense is not optimized for a high number of interfaces. We're now in need of a network and firewall redesign. Nothing we can't handle, but obviously it would've been great if we had known this right from the beginning.

Maybe someone will take this as an opportunity to add this information to the documentation. Currently the only hint that a "high number of users or interface assignments may be less practical" can only be found in a footnote of the product description of the appliances. It doesn't say what "high number" means - could be 10, 100 or 1.000 depending on who you ask - and the word "impractical" doesn't mean that the whole system will collapse. Some hint that with decent hardware up to 100 Interfaces is likely fine and beyond that performance issues are to be expected. :)

Initially, you said that a large number of updates causes the problem, not that it occurs out of the blue. When you deploy a new instance, this boils down to a high initial load with OpenVPN, because of the certificate handshakes.

Correct, that's where the whole thing started: We installed OPNsense on our somewhat older server hardware (8 cores, 16 threads, 128GB RAM). For the most part this worked just fine, but we had some issues during traffic spikes. After our attempts to solve the problem via tuning failed, we switched to the best server hardware available to us: Intel(R) Xeon(R) Gold 5218 CPU @ 2.30GHz (32 cores, 64 threads), 384 GB RAM, you get the idea. This was meant to be a temporary solution as this hardware seemed way too much for that purpose and was intended for running 20+ virtual machines instead of just one firewall - and we'd need two of those machines for redundancy.

In order to rule out any hardware or driver issues, we decided to get the appliance - which performs much worse than our old server. :-(

Anyway, if the problem occurs even without specific traffic spikes, it seems to be the pure number of VLANs involved. I would argue that it is quite unsual to have that many.

I agree with you that this is indeed somewhat unusual, but that's what we've got... ;-)

Probably the routing table hashing mechanism in FreeBSD is not optimized for that (or can be tuned by enlarging the memory for it). As I said, I am by no means a FreeBSD expert, but I saw that you can even set the routing algorithm, see "sysctl net.route.algo.inet.algo".

My knowledge about FreeBSD is even more limited, but this looks like a good starting point for some more research... :)

Thanks
Thomas

So basically what happens is that 300 VLANs - which presumably connect to a similar number of client machines - use VPN connections, capped at 4 GBit/s total. When all of those act in parallel, the problem occurs.

The problem already occurs with no traffic at all. With the exception of one 1Gbit/s interface solely used for administration and accessing the GUI, all other interfaces were physically disconnected. (They were - of course - enabled in the configuration.) There were some VPN servers configured and activated, but they weren't being used. To be precise, we have two legacy OpenVPN servers, one "new" OpenVPN instance for testing purposes and one WireGuard instance also for testing. Apart from that, everything es is simple routing/NAT. There is a total of 2% (18875/1000000) firewall table entries.

Even then, there is no single user process that the load can be attributed to. Thus, I would guess that the VPN calculations are the culprit. Those may be delegated to the FreeBSD kernel. The interrupt load could also point to that (maybe induced by context switches).

While the first sentence is entirely true, there should be VPN calculations whatsoever as VPN wasn't even used and won't ever be used to a greater extent. Even in production, there are at most 10 OpenVPN connections (road warrior).

Depending on how the VPN infrastructure is built (site-2-site vs. client-2-site), you probably could use different VPN technologies (e.g. Wireguard) or employ different ciphers, which may lead to better parallelism, if my guess should turn out to be the underlying problem.

I do agree that a significant number of established VPN connections might indeed be an issue, but this is not the case.

We finally got our DEC4280 Appliance and gave it a try. After installing all available updates we imported our original configuration (with some slight changes to match the new device names). Bootup took around 15 minutes - a bit longer than usual but that's ok. Even with just one network interface connected for administration, the GUI was extremely slow, the whole system was close to being unoperable. A simple change to a firewall rule could take as long as a minute to apply. At this time there was absolutely no traffic being routed, no captive portal clients trying to connect - there was nothing at all!

So we have the best appliance available but the system won't even run our configuration without any network load? I'm aware that our setup is quite big, but is it really that much beyond what OPNsense can possibly handle? After all, it's not the network traffic that causes issues, and we aren't even thinking about things like intrusion detection - the only thing we've got is a lot of interfaces...

As the integrated netflow feature only supports up to 8 interfaces simultaneously, we decided to set up an external server to collect netflow data for further processing. Since our hardware is quite capable (we thought), we activated netflow on all ~200 interfaces (mostly VLAN) at once which basically crashed the whole system. Of course the primary lesson of this is, to never ever and under no circumstances do anything on more than 10 interfaces at once, unless you're begging for trouble and feel a really strong urge to bring in cake on the following day which is how we usually deal with colleagues accidentally breaking something. ;-)

But seriously, how much load is there to be expected per interface sending netflow data to an external server? Does it depend on the amount of traffic on that interface or is that irrelevant? Is activating netflow on literally hundreds of interfaces something that a well-equipped system should be able to handle or is it way beyond of what any powerful system can do?

At the moment this is not about identifying problems and finding tuning options to solve them - it's about making sure that what we want to do is something that actually can be done.

Thanks
Thomas

I'd say the proper place is /usr/local/opnsense/service/templates/OPNsense/WebGui/php.ini - followed by

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configctl webgui restart

for changes to have effect.

Thanks! That was it! I already identified that file and modified it, but I did a

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service configd restart

as suggested by - among others - ChatGPT rather than a

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configctl webgui restart

That did it. :)

Thanks.

[how]

Hi,

I'm currently getting the following error message whenever a hit "Apply Changes" in interface configuration:

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PHP Fatal error:  Maximum execution time of 300 seconds exceeded in /usr/local/etc/inc/plugins.inc.d/ipsec.inc on line 144
Occasionally it's in a different file, but I don't think that matters. After some examination I have a good idea of what's happening and I know what I've done, so I'm aware what's caused it. If I'm not totally wrong, I know a way that should fix this once and for good - I just don't know how to do it.

I was tasked with reconfiguring some 80 interfaces - a rather simple change of the respective interface IPs. Applying changes after one interface takes between 30 and 60 seconds. Don't know why it takes so long, but it doesn't really matter. We have a rather big setup which is working just fine, so this is not a problem as that kind of change is not something that we do frequently. Rather than doing something every single minute or so I figured it might be a good idea to do a bulk change meaning I reconfigure a greater number of interfaces, then hit "Apply changes" and have much longer time that I can use to do something else. This was a bad idea, because after some time I get the error message mentioned above. About 20 interfaces have been reconfigured as expected - the other ones haven't. Hitting "Apply changes" will start the whole process from the very beginning, which I suppose is "by design".

I can think of three different approaches to this problem - in order of preference:

• Applying changes to each interface individually on CLI.
• Temporarily increasing PHP max_exection_time.
• Rebooting the system.

So far I haven't found a way to do (1) and I'm open for suggestions. As for (2), I have tried modifying max_exection_time in /usr/local/etc/php.ini as well as in /usr/local/lib/php.ini, which are the only places where max_execution_time=300 is being set. (I changed the value to 3000 as this is only meant to be a temporary fix.) However, that doesn't seem to change anything. Rebooting the system (3) would cause a downtime that I'd like to avoid. This will be my last option if everything else fails.

Thanks
Thomas

Sadly, I just found out why there are no more error messages: The whole CP is down... :-(

According to the log files, the service is starting normally, but ports 8000 and 9000 are closed. We checked the limits (ulimit -a) for root and www users - no problem there. Any ideas?

But there're even more strange things...

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ls -lh /var/etc/lighttpd-cp-zone-0.conf
-rw-r--r--  1 root wheel  1.2M Mar 24 08:15 /var/etc/lighttpd-cp-zone-0.conf
Notice the file size. At the beginning of the file, there's one extremely long line consisting of characters that can't be seen. After that, there's this:

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              # ssl enabled, redirect to https
                       
#############################################################################################
###  Captive portal zone 0 lighttpd.conf  BEGIN
###  -- listen on port 8000 for primary (ssl) connections
###  -- forward on port 9000 for plain http redirection
#############################################################################################
#
#### modules to load
server.modules           = ( "mod_expire",
                             "mod_auth",
                             "mod_redirect",
                             "mod_access",
                             "mod_deflate",
                             "mod_status",
                             "mod_rewrite",
                             "mod_proxy",
                             "mod_setenv",
Nothing suspicious after that. Now I don't think this has anything to do with our orginal problem, but it still looks strange to me...

Well, I think it's safe to assume those limits are there for a reason ranging from "Nothing. You may just waste some resources that nobody really cares about on any modern system." to "Setting this too high may eventually crash the whole thing." - and since I'm on a production system, I prefer being a bit too careful rather than sorry. ;-)

Anyway, it looks like "Mission accomplished!" to me. I kept doubling those numbers until the messages disappeared. I ended up with

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## number of file descriptors (leave off for lighty loaded sites)
server.max-fds         = 131072

## maximum concurrent connections the server will accept (1/2 of server.max-fds)
server.max-connections = 65536
which I suppose gives you an idea of just how busy our CP is. ;-)

Besides, I'm not sure if it has something to do with it or because it's Friday afternoon, but the load average on the whole system seems to be down significantly - from ~15 to ~3.

Thanks and have a nice weekend!
Thomas

[seems]

Hi Franco,

looks like that helped... a little bit... maybe... ;-)

There are still a lot of messages, but the rate seems to be somewhat slower - down by a roughly a third I would guess. I do assume that this is because of the applied patch - not because of less traffic on the captive portal. Is it safe to simply increase those numbers until everything works? By that I mean applying a factor of 2, 4, 8 or perhaps 16 at most - not hundreds or thousands. ;-)

[could]

Great, I'd be more than happy to give it a try and tell you what happened. ;-)

I found the options in

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/var/etc/lighttpd-cp-zone-0.conf

where they're unset. Of course I could simply edit that file, but I'm afraid that change will be overridden as soon as I make any changes to the CP configuration if not even sooner, so what would be the best place to make this setting persistent?

Thanks!
Thomas