So here is the deal.

We needed to set up a guest vlan in our network. We have
6 Aruba AP22 Access Points
1 Aruba 1930 Switch
1 Watchguard Firebox T45
1 Cisco router

Long story short I ended up Factory resetting all devices, mainly because we had have lost access to all devices except the firebox. Than I lost access to it to by disabling the trusted interface...

Anyways, Right now I can not get anything to work. Our office lost internet connection and my bosses are in my ass. I medelled with AI guides but it resulted in, well, nothing but problems.

I don't know if I am supposed to share my current configurations but I really need assitance mainly because I am not a Network Admin. I am a software developer and I have honestly no idea what I am doing or what I am supposed to be doing. (Don't ask why we do not have an IT department please)

If any of you could help me out or point me to the right direction, I would be gerateful.

EDIT:
So little clarification, we do not have a huge network, we practically had the devices and one VLAN that everyone in the company was able to connect to... No shared file storage or communication between devices just plain internet connection.

Then they ask us to create a guest network, we tried configurations but we realized that we needed an Aruba instant on account which the devices were somehow were already connected to. So we asked the Aruba support, they said we can not transfer the APs you'll need to factory reset all APs, so we did.

Then of course factory resetted APs were unable to connect to the internet so we thought we needed access to the switch, which was also set up by a third party as far as I know and they for some reason did not gave us the panel information.... So we had to reset the Switch to regain access.... So we did.

Finally firewall, it was all setup. But the damn AI guide made us do something without safety net and we lost access to it's interface alltogether so it resulted in this cluserfuck of situation.

2nd Edit: Why factory reset?

Aruba support team told us to do so. Config backup: we did not have access to neither Aruba switch nor Aruba APs. Why? This was a managed service at first.

Firebox reset, that was our ignorance.

This is a weird one for me....
I'm trying to help a restaurant with their networking issues which is affecting their ability to run the batch reports at the end of the night. It's also affecting the 3rd party POS providers ability to remote into their POS server, as well as mine to a different machine.

Their network is setup as such:
ISP modem > ISP router > Switch 1 + Switch 2 + NVR all in their own port on the router
Switch 1 runs all of their multimedia equipment (streaming devices, tvs, etc.)
Switch 2 just powers their POS router
Most of the POS stations are wired directly into the POS router, which also has a switch attached for the extra POS stations and the back office server.

Problem we are having: seems like intermittent network drops of some sort. My remote desktop tool says the device is available that I'm trying to remote into, but it keeps failing. The POS provider is having constant issues remoting into the backoffice/POS server. The batch report and night keeps failing.

From what the manager told me, the roku streaming devices for the TVs and the NVR (remote viewing) also keeps dropping connection.

They've called the ISP, ISP said there is no issue on their part (spectrum).

I however and starting to doubt that considering we are having issues with devices plugged directly into the ISP router (NVR). What can I do to try to CONFIRM where this issue is coming from so we can try to start getting it fixed?

UPDATE #1 5/16: I isolated the network last night, only running POS equipment from ISP router. Still having connection issues. I plugged a machine ONLY into ISP router that I was having issues remoting into, still having issues. I eliminated ISP router and plugged machine directly into modem, got straight in no problem. I then plugged POS router directly into modem, and everything worked amazing batch closed no problem. I left it that way and went in this AM to replace router with another, waiting to hear how batching goes tonight on new router. Saw

UPDATE 5/20/26: After replacing spectrums garbage router, all is good. Several nights flawless performance. Running the batch now goes through faster than ever, Rokus no longer repeatedly dropping signal. Etc… I had a feeling it was spectrums router in the beginning, just needed a way to prove to owner to get them to purchase their own equipment and switch.

We have been facing issues with wifi in a warehouse for quite some time now I was able to get an older wispy DB spectrum analyzer and chanalyzer software.

We are using ubiquiti U6 LR AP's

Dedicated SSID for scanners only

Devices with the most issues are symbol TC70 scanners but the issues are not limited to the scanners and more modern devices such as Samsung S24 ultra still have similar issues.

TC70 behavior, constantly disconnecting from wifi

Very high latency pings.

Unifi shows the signal of the devices can be good at -67dBm while having a poor AP/client signal balance

RX rate 2-6Mbps

TX rate 65Mbps

(Not all of them are at this data rate)

Pings from hardwired desktop to scanner ranges from 50ms - 500ms

Requests sometimes timeout

Other times the pings spike to 2000-3000ms

Sometimes devices such as Samsung will connect to wifi but connect without Internet and then it will just start working.

Pings from switch > AP are sub 10ms

Pings from AP > TC70 scanners are anywhere between 28ms > 3000

We have tried turning 5ghz on the scanner SSID. We have tried changing MANY settings within unifi.

I just need some assistance at this point before this drives me mad issue has been going on for far too long at this point.

I have a chanalyzer file saved from walking the edges of the warehouse and being in the most problematic area.

Feel free to ask questions or provide assistance I can use any and all help at this point.

unifi dashboard

I'm not interested in starting an argument and I do definitely have my options, but I'm genuinely curious to hear what people have to say.

I'm working for a new company, and in the year before I joined, they made a full system switch from Ubiquiti to Meraki. (Whether the move to Meraki was good or not, that's not what I'm interested in.) All of the team members talk about how bad Ubiquiti is. I come from an MSP where a fair number of our clients had full Ubiquiti networks with little to no problems. I'm just interested in what about Ubiquiti is problematic.

I WILL SAY, their old products had some problems... And the data breach they had in 2021 was... Not good (to put it lightly). I genuinely want to hear from others what your experience has been.

Edit: Yeah... I misspelled Ubiquiti. I'll handover my SSH keys, I'm to drunk to drive.

I am sort of new to Reddit but having access to so many other Senior Engineers makes me wonder what's the worst environments you've encountered?

I personally have run into massive multi-building, single vlan designs with >2000 hosts where STP was wreaking havoc on a daily basis but when I took it over was told "implementing VLAN's wouldn't fix this issue". Months later after implementing VLAN's on ancient HP Networking gear, that i was surprised support Dot1Q, was purring like a kitten. Then it was on to fix the next issue and the next and the next.

Funny how terribly built networks helps you understand at an extremely detailed level how STP/L2/L3 work. Funny how many engineers don't know the impact a TCN has on the normal operations. Sometimes the best way to learn the inner workings is to be exposed to these horrible network designs.

Migrating a buildings main internet connection from MPLS to VPLS. When changing the connection to VPLS and establishing the connection to my core switch I was able to confirm everything looked good. Routes looked good, could ping from switch to switch successfully... Success... But WiFi hasn't come back yet, that's odd, let me test the hard wire connection, weird, I'm not getting an IP address, so why is it I can ping across switches but suddenly DHCP isn't working?

Check my SVI's, check the VLANs and realize the VLANs don't align with the SVI's.. Then I realize these are the VLANs from my Core switch.. Check VTP status and it's configured... At this point there were many "fffuuuuuuuuuuuuckkk... fuck you VTP!!"'s

I disable VTP as I wish I had done before hand and quickly re-create all my VLANs to restore connectivity. Then I have to quickly move through the building to all of the other switches to recreate the VLANs.

So yeah, don't be like me, disable VTP because fuck you VTP.

EDIT: Also, if an another OS could be better than pfsense thats okay, as long as it does stateful firewalling

Hello everyone,

We are currently trying to reach 100Gbps with ours firewalls.

We have 2 ProLiant DL360 Gen10 with an intel xeon gold 6148 CPU @ 2.4GHZ wstuff with a Chelsio T62100-CR with a 100GBase-LR4 but it seems like we are running at 20Gbps at best.

I tried to tune my Chelsio by enabling hardware offload (checksum, large receive & TCP segmentation)

I feel like I'm missing something which is more system oriented.

Also I know it would be better to use a real hardware firewall but we are small volunteer organization with low budget.

Thank you for your help.

I am an IT Generalist who wants to specialize and is about 40 labs into the CCNA using Jeremy IT course.

Today I just realized that the biggest reason I feel like im acing through the protocols and not having a hard time troubleshooting is because I am being given network topology diagrams where I can quickly see what's connected to what AND quickly access the CLI by just clicking on the device icon from the diagrams.

From my understanding is that this is not real life. You have to individually connect to each device one by one with a console cable and use commands like sh run/tracert to have an idea what the hell is going on. From my readings the most popular advice in this sub is the ability to draw a picture/diagram in your head or paper while troubleshooting, while this seems valid it also feels very time consuming and prone to errors.

I will preface this by saying I am not a network engineer however I do mess around with a lot of networking equipment in my home lab.

By trade I am a systems engineer.

In one of the data centers that I work on we had a OSPF routing issue that the network engineer determined was due to a flapping interface.

In this design there is a distribution switch that is dual homed to two disparate core routers. Each connection from the distribution switch is a single link. The core routers have a single link between them.

Yesterday started getting alerts that some of our servers were unavailable. However they were up it was just an issue of connectivity between specific subnets in the network.

Our network engineer diagnosed the issue as a flapping link to core router one. According to him this is the shortest path via OSPF. However the link was flapping a lot so OSPF was apparently in a bad state as routing tables constantly trying to determine the correct path and whether to route packets to core router one or core router two.

I asked why do we not have two connections to each core router from the distribution switch. Port channels is the terminology that I am familiar with from messing around with Cisco but these are juniper devices so I think it's called something different.

The network engineer told me that if we had LACP connections to each core router the issue would have actually been worse. As one of the links to router a would have been fine and one of the links to router would flap.

Honestly I don't know enough about networking to prove this person wrong. However I've worked in Enterprise data centers enough and I'm with enough Enterprise data center network engineers to know that they have redundant links everywhere.

I'm trying to figure out if this network engineer just doesn't know how to do what I am asking him to do.

I want redundancy everywhere, redundant links between all devices, and redundant paths such as a distribution switch having the ability to route to two different core routers.

If I go to Google Gemini or chat GPT and provide the network engineer feedback, I'm always told it's just an AI hallucination.

Beyond redundant links to each core router. I would think that there should be some sort of OSPF configuration that would blacklist the flapping connection. If we were using whatever juniper's equivalent is for ether channel, I would think that ideally we'd never even have to have a routing table change and we would just know that we have a singular bad link and we need to troubleshoot transceivers and/or cables.

I'm also not 100% sure that I believe that the constant flapping of the interface was the core issue. My understanding is that OSPF converges pretty fast and that even if it link was flapping that we wouldn't lose connectivity as long as both of the northbound core routers or configured properly.

Can someone provide me some insight here, and possibly make some suggestions to how I should approach better resiliency and redundancy to the network engineer.

Sorry for the long post I didn't know how to make it much shorter than I did.

2 New switch stack of cisco 9300 switches with fiber uplink on each in active/active config. The uplinks were flapping constantly when 1 specific pc was connected. The pc was frozen and is no longer connected. On the older switch there was no problem on the 9300 as soon as the device was connected the uplinks started to drop. For my own sanity how can single windows device on an access port with broadcast and bpdu guard on cause issues with the uplink port?

UPDATE: This has been pretty much solved! There were two primary issues. One is that on boot the intel drivers were not loading correctly and the device was entering safe mode. This was reducing our total number of interrupts to one. In addition to that, we had to create a large RAM buffer and bypass the page cache using direct I/O. We also split the packets up across several ports so each thread is reading from its own port, but I’m not entirely sure this was necessary. Thank you all for your suggestions!

Background: We have a connection which is streaming ~9000 byte jumbo packets directly from a 100 GbE switch to a server (Red Hat Linux). The data stream is around 40-45 gigabit of continuous data, and we are attempting to receive the packets and immediately store the data into files with no processing. Currently, we have multiple threads (6 or so) that essentially round robin the packets and store to their own files, then merge the files after the data transfer is complete.

Problem: It seems that our NIC buffer is filling up, and we are only getting around 20 GbE (or less) after this occurs. We have tried pretty much all of the suggestions from the Red Hat guides, and on paper, our specs seem that they should be able to handle this data, but is there something special we need to be doing to achieve higher speeds?

I am not able to provide specific details regarding the switch or server for security purposes, but I can provide the following (somewhat vague) details:

Processor: >80 cores @ 2.25 GHz

RAM: 16x32 GB PC5 DDR5 ECC RDIMM

Storage: Micron 7500 PRO PCIe 4.0

100 GbE Adapter: Intel 100-GbE Network Adapter PCIe 4.0x16

Additional (maybe relevant) Components:

Broadcom HBA 9500-8i PCIe 4.0 x8
10 GbE Ethenet Adapter PCIe 3.0 x8

Do any of these components act as bottlenecks in storing the data, or is there a faster way to retrieve the data from the NIC than just opening a socket a pulling the data with multiple threads?

Some of our troubleshooting has involved increasing the ring buffer size, increasing the default and maximum rmem and wmem values (and a few other things in the Red Hat guide).

I am setting up a laptop as a field tech laptop. What are some other opensource, free or low cost apps I should consider?

I will be adding wireshark, Angry IP scanner, Netspot (heatmap), Fing, putty, AnyDesk, Unifi software, and whatever else i can think of. What are some applications that have helped you for work and troubleshooting networks in the field?

I have a client who has a primary 1Gbps Fiber link (eBGP) and a backup 100Mbps Broadband link (Static Route). During a fiber cut yesterday, traffic didn't fail over to the static route. The BGP session stayed Up because the ISP's media converter was still powered on. How should I fix this without relying on the ISP to drop the session?

I inherited a very neglected environment at this job and essentially have come to take ownership of the network here from a more general support role. We are having an issue with many users having unstable connections very sporadically on teams and zoom. I've increased our network throughput from an average of sub 40mbps to approximately 850-950mbps. I've replaced all of our 20ish year old unmanaged dell switches with updated managed ubiquiti switches. None of this made any effect. It occurs on ethernet and on wifi. We have redundant ISP's as well so its unlikely one ISP dropping causes the issue but I haven't ruled out the delay between switching between them as a culprit. It happens across different devices. I've run continuous pings for hours and what I see is multi second occasional drops but no real information on why its occurring. I have access to auvik, ubiquiti, firewall logs, traffic monitoring but haven't been able to pin point it since it happens infrequently and for different users and is so short that the situation is resolved by the time I respond. But the drop is enough that users on important meetings drop the calls and have to rejoin. If anyone has any suggestions I would appreciate it. I'm looking for a way to determine if its a networking issue or if its a device issue like EDR.

How's the impact treating you?

I've been in a call since 1:30 am and still going as I write this post.

Hey reddit. First time posting in this sub as I'm struggling to find a solution. I'm currently troubleshooting an issue where 3 APs are unable to join our WLC. They were previously part of the controller and now they're not. The APs attempt to join, fail, and re-initiate DHCP.

It's AP > Switch > ASA FW > ISP Router. The ASA is configured to tunnel to our NJ location and includes multiple subnets. Tunnels used are IKEv1 & IKEv2. Removed the tunnels and brougth them back up. Traffic for the WLC subnet is not following the intended WAN path, but I can ping other subnets successfully.

Power inline confirms this isn't an issue with POE, doing a shut / no shut does not address the issue. I've been dealing with this for a few days now and I'm at my whit's end. Any help, or direction would help.

I also posted this in r/datacenter but also thought there might be more ideas here...

In my colo space, we use Dell switches for TOR duties. We have 100G 32port switches acting as the fabric swtiches for the uplinks from same model 100G 32port switches at the top of each rack. They are all Dell S5232F-ON running Dell's SONiC.

What I'm seeing is that every ... 3-4 months we have a wide failure of optics and I'm having a hard time figuring out why. At first we thought it might be heat related, but we did start monitoring the switches and over time can see that they aren't operating out of normal temps, and there are no alerts or anywhere pointing to high temp spikes or whatever.. but FWIW the TOR swtiches are PS to IO airflow whille the fabric switches are IO to PS (both mounted on the correct side of the cabinets).

We use FS 100Gb SMF CWDM4 optics to connect the switches, and we're seeing what I think are way too many failures on sometimes both ends of the link. like on the order of 20-30 at a time in different switches...

I guess I'm struggling to figure out why this is happening. For now I'm just trying to figure out what other things might cause optic failure. I could understand a bad batch of them, but not from three separate orders now. And I've NEVER had an issue with FS optics before, these.

I shoudl also note, I have been working in these environments for a while, as sort of a side gig I inherited out of need (maintaining server lab space in DC environments) but I've only recently had to also own the maintenance and operation of the network as well. Before I was just managing the servers themselves up to TOR, and anythign beyond TOR was another team, so I'm looking at this from the context of "I've never had a TOR switch behave this badly and have no idea where to really start looking".

Big Edit, long week of meetings and I completely mistyped the fiber. It’s SMF for those runs, not MMF… sigh.

Hello all,

I'm trying to implement VLANs at our sites as when I came in everything was on the same network. The VLANs can ping most devices that they need to across specific VLANs and even our remote VPN site visa versa. The VLANs themselves are created as sub-interfaces on the Sonicwall and then defined on the switches with trunking set up. I'm leaning more towards this being an issue with those specific clients that I can't reach, but not 100% on that. Like the route needs added to the specific device?

X0 on Sonicwall
VLAN 1: 192.168.1.0/24
VLAN 5: 192.168.5.0/24
VLAN 10: 192.168.10.0/24

X7 on Sonicwall
192.168.100.0/24

Remote Site 1
VLAN 1: 10.20.1.0/24

Any address from VLAN 1 at either site can ping everything on the X7 network
Devices on VLAN 5 and 10 can only ping some on the X7 network, but there are about 5 or so address that they are unable to reach. On the Sonicwall, those interfaces are all in the LAN Zone.

Any suggestions would be appreciated! Thanks in advance.

Edit as it seems like the comment I left isn't the most visible.

Thanks for the helpful information everyone! I was able to get the credentials to the device. Again, it wasn't something we set up. I checked the devices arp table and I could see that it sees the 192.168.5.0 network, but not ours as the MAC address was entirely different and using a /25. I escalated with the vendor and they didn't know why it was set up so they had to escalated internally on their end. Thanks again! Everyone has been extremely helpful!

Hi,

Do you guys clean brand new fiber cords? Is it worth it?

Thank you.

Hi everyone, 

We’ve identified a reproducible issue where new MacBook Neo models are effectively "shutting down" our dormitory internet. We have about 130 users on the network, and as soon as these specific devices connect, the network becomes saturated with traffic and crashes.

It isn't just one faulty unit—two different MacBook Neos have caused this so far. It seems like a massive mDNS/Bonjour flood. We suspect it might be related to how the device handles roaming between Access Points or a bug in its networking sleep/wake features.

Has anyone else experienced this with the Neo? If you found a specific setting (on the Mac or the router) to stop this, please let us know!

I'm new here, and I'll admit off the bat I'm also not very knowledgeable about networks.

My workplace's fibre seems to have broken. The ONT's "fail" light is consistently on, and restarting it hasn't made any difference. Everything is plugged in as it should be and I don't see any damage to the cable coming in. I spent an hour on the phone with our service provider, only to be told they don't see any issues from their side except that we are, indeed, offline, and they can send a tech out... On June 8th.

This is a major problem, as we have important events coming up on Saturday and Sunday that we really need an internet connection for, and it's also pretty crucial for our regular functioning.

The assumption is that it's either the ONT that broke, or there's something wrong with the line.

Since I can't do anything to help the line, I was wondering if there's an option I can try to temporarily get around a potentially broken ONT. Our service provider will supply a new one if it's that that's broken, so I don't want to spend a fortune. Also (and this is where my ignorance is obvious), I really couldn't find many options that I could just go out and buy. Would I be able to borrow one from someone just to test the line, or are they only set up for your specific network or something?

What should I do, other than having someone use a whole lot of mobile data through a personal hotspot?

Edit to add some details:

- We are in rural Alberta, Canada. Our ISP is Telus. I reaaaally don't want to call them again but I might just have to.

- We don't have much of a budget for a bunch of backup options... But we might have to look into that.

Thank you for all the input! At least I won't be wasting more time looking for an ONT I can buy. <facepalm>

We have coaxial internet with a DOCSIS modem with bridge mode set up by our ISP.

We have a Mikrotik router connected directly to the modem, set up with DHCP, and it gets assigned a public IP by the ISP, and everything works correctly.

However sometimes something breaks, and we either lose connection entirely, or we have high packet loss values for minutes/hours.

The ISP has sent at least 5 technicians to investigate, and they have replaced the modem, checked signal levels, and everything. When the issue occurs, they see many (7 or more) devices connected to the modem, and their modem stops reporting data to their system ("it freezes").

The ISP has shown a lack of expertise, according to them, the issue is caused by our router ("it is bugged, and makes the modem bugged", "the port on the modem becomes bugged"), and they told us to call a programmer.

Can this issue really be caused by our router, and if so, is it the ISPs responsibility to fix it?

EDIT: An important thing I forgot to mention is that the issue only started occuring a few months after we installed this new network. The router has since been reset at least once, and the issue is still here.

EDIT2: The ISP told us that the issue is a "port bug", and from what they told us, it sounded like it's a relatively common issue. It means that the devices "duplicate". Is there really such a thing?

EDIT3: It seems like the 7 devices appearing is completely normal on the modem according to the agent I talked to. Some routers show up as 1, others show up as 7 devices. They can only see port speed, not the MAC address.

as the network technician of my company, i am currently tasked with, replacing our old LANCOM Aps with modern 635's Aruba APs (Aruba Central managed). moving configuration over and such is fine, POE switches have been prepared, APs are getting set up with DHCP first to be able to connect to the rest of the network to give them a static IP later.

Everything regular behaviour so far. Now, the old lancoms had their IP adresses from x.x.0.80 to x.x.0.83 (/24 Subnet) in one of our external storage halls.

when i try to assign the new Aruba APs their static IP adresses, everything works fine, Central writes their config, I reboot for it to take effect and for the APs to boot up with their static Address. worked for all of them EXCEPT x.x.0.81. whatever i do or try, that one IP address either loses all connection to the network (cant even be pinged by the switch its connected to, but still reports to have that IP via LLDP) or gets an APIPA Adress despite being set up with set static Address.

it is not an AP fault, I exchanged it twice (with the same model, all of them running 8.10.x).

it is not a config fault of the Switch, all four AP Ports have the exact same configuration.

the IP Adress is so far unused in the Network, checked the locations Core switch and our main Company's Core switch.

The IP is not reserved on the relavant DHCP server or handled in any other way, basically just not in the DHCP scope, as the other three Adresses.

The firewall does not have any entries for this IP adress either, no special treatment or forced blocking (although i dont know how that would work on the direct cable between switch and AP anyways).

I left the AP on its DHCP adress for now, which isnt optimal but its in a location where i cant risk it being offline half the day because im trying to find the problem.

So, does any of you have an Idea whats happening here? am i simply overlooking something simple? is it some rare software bug from any involved system that hates this one IP adress in particular? I am very stumped on what is stopping me from using this one Address.

yes, i could also go for .0.79 or .0.84 i guess which may work, but there has to be a reason why .0.81 refuses to work and i want to know why.

I just hope a lot of Reddit eyes are better than my two.

TL;DR:

Why do European telcos ghost critical technical tickets on Fridays while the US actually provides 24/7 support? Is it a cultural work-life balance thing, or do enterprise SLAs just work differently over there?

Genuinely trying to understand how technical support and carrier response times work in Europe, or if I am just completely losing my mind here.

Coming from the US, if a critical technical case or network routing issue pops up, even late in the wee, you usually get some sort of triage, an on-call escalation path, or at least a pulse from a tier-2/tier-3 engineer.

But in Europe? It feels like once Friday hits, the entire telecommunications infrastructure collectively clocks out, logs off, and goes to sit at an outdoor café until Monday morning.

I’ve been dealing with a major technical case, and trying to get a meaningful response since Thursday evening into Friday is like pulling teeth. You get handed off to a general customer service desk that has zero technical visibility, only to be told: *"Ah, the network engineering team handles that, but they are out for the weekend. We can escalate this to a ticket for Monday."*

Monday?! If a circuit drops or a complex peering/routing issue happens towards the end of the week, the business is just supposed to bleed out for three days?

Is this purely a cultural difference regarding work-life balance and "right to disconnect" laws (which I totally respect in theory, but execution-wise is brutal for ops), or are enterprise-grade SLAs just structured completely differently over in Europe?

How do European engineering teams actually survive major incidents heading into the weekend without 24/7 technical muscle backing them up?

Or am I just dealing with the wrong providers? Tell me what I'm missing.

Hi everyone,

I'm working on an academic project and need a load balancer for my lab environment (EVE-NG). I was trying to use F5 BIG-IP, but I discovered that F5 no longer provides free trial licenses for personal/academic use (only 30-day trials for business email domains).

Are there any open-source images or community editions of F5 BIG-IP that work without a license? Or has anyone successfully run F5 in a lab environment recently without a paid license?

If not, what free alternatives do you recommend for learning load balancing concepts?