HW074: Build Your Own Access Point with Bradley Wegner

0:00Welcome back to another episode of Heavy Wireless, part of the packet pushers podcast network. My name is Keith Parsons and today I'm here with a guy who invented Todd and kind of started this whole new deep dive we had at WOPC this year called build an AP, build your own AP. Brad, how are you doing? Doing great Keith, thank you for having me. So what made you start with this build an AP idea in this in the in the first place? I've always been interested in what the components are in hardware and conversations in Prague this last fall at WOPC in particular one with Brian Ward really got the wheels turning in my head about you know I want to come to an event like WOPC and I want to I want to build my own AP and going through that conversation I got excited and then my wife who was with me she could

1:02just see all the people around me lighting up because everybody just seemed to just gravitate to this idea like how fun would it be to get your hands on it and to actually touch the components and and put some some effort into making something and getting a little bit more hands on instead of you know remote from that from the hardware so you know many of the many of the stuff is about analyzing the packets or it's about doing the automations or it's about interfacing with a command line very few of the activity that we do really get your hands on hardware and as kind of a hardware or not it's something I really wanted to pursue. I'm glad you did and it was very successful but I just want other people who are listening to know every single deep dive started the same way yours did somebody had an idea they're talking to friends then it wouldn't this be really cool and they realize other people want to learn the thing you have and so I'm glad you took your expertise or at least built the expertise to do this. So what was your process of

2:04going through from that idea we need to build an AP to actually coming up with a what hardware what software firmware yeah so it got really interesting so you know I'm all wired up and just jazzed about this whole concept and I start looking at embedded boards and the cost for astronomical for a lot of these I remember I was looking at a Qualcomm chip embedded board and I got a quote back from manufacturer for about a thousand dollars per device and I knew that that just wasn't going to fly so I started by taking a part an old 2702 that I had in the basement and just kind of looking at it and going okay what are the components that I really need to build a wireless access point does it need to be a flagship AP or is it okay if it's just you know like a 2 by 2 by 2 something serviceable but not necessarily extremely complex and so I was

3:09kicking around some ideas looking at some of the better boards and then again Brian came up with this banana pie board and shipped it over to me meaning he sent me a link and I started digging deep into this hardware and it was really compelling because it met a good compromise between you know something like a raspberry pie with a consumer grade radio which is boring in my opinion for an AP versus something that's you know a complete flagship $3,000 AP that's you know got all the bells and whistles so I really just wanted us to get to a point where we would be able to do something that would operate maybe like a small office network and if it had some bonus features that would be great but we had a compressed timeline because once the once the announcements were made about which classes were selected you know the hunt was on I really had to get moving especially

4:11after you got a bunch of votes and I said hey you're going to be in the registration yeah yeah that was really exciting so once once once that happened you know then we had order the gear but we had to wait for a slow book from China so there was you know a three or four week waiting period right I'm just waiting on hardware waiting on hardware waiting on hardware and the hardware finally came gosh I think it was like New Year's Eve so you know WPC was in Prague that was in October now here it is you know almost a month and a half later and I'm just now getting the hardware and oh by the way I've got to be able to have my lab developed everything built everything ready to be able to present it to Keith and for an A in February prior to the conference and so it was a mad dash luckily the banana pie org had just a wealth of information on how to get started out to do different things and there was a bit of a user community out there already for these products

5:16some of the media tech stuff which is the the the manufacturer both of the processor for the system board as well as for the wireless card they they have some support tools and they have some independent utilities that are built for the open wrt platform which we ended up using but the some of the branches you know were several versions old in the open wrt and they were not you know forked back in and so you couldn't you couldn't update them and so there were considerations we had to make there where how do you you know how do you build a lab and book material out there for students but then give them something that's you know essentially they can't update from a security perspective if someone was going to put this on their home network I didn't want to have that kind of liability I didn't want to I didn't want to introduce that kind of vulnerabilities to somebody's home environment and so we ended up going with a with a main branch of open wrt

6:19that was available through their through their website and we were able to download specific images that were slightly customized for the for the banana pie worked out really good initially and then I tried to configure six scarehertz so really ran into some headaches configuring six scarehertz due to some regulatory domain complications when we were going through doing the labs and this was mainly because the media tech the media tech chips did it have the FCC information loaded directly on them for the US so they had no idea how they were supposed to behave in the United States in six scarehertz and so they just wouldn't turn on in six scarehertz and we did some some hack techniques and allowed to kind of get past that but I'm happy to say now that that that issue has since been patched and corrected and there's there's some software for that I found that out actually for one of my students in the lab which was a really cool that meant that they were engaged right like they're already looking at

7:23the bugs and they're checking the files and they're they're getting into it and so by the by the time we checked that out I had a student who already patched his patched his device with the latest updates before the deep drive even ended so it was it was a really happy ending to that story. Let's let's go back and talk about two things one WMPI has been around for a long time and one of the one of the base features built right into the front panel manager system is you can turn into an AP it uses its internal link it's used in a port and you can configure like a little hotspot you plug into a hotel it's not I mean it's it's an AP running WPA applicant it works but it's not really very powerful what's the hardware that's behind this banana pie I mean it's it has the word pie so it sounds like a raspberry pie but it's not real yeah no it's not so it's a media tech phylogic 880 processor it's got a nand memory and that it also has an emmc flash

8:24for storage and then depending on the model that you get you can have four or eight gigs of ram installed the ones that we used in the class were four giga ram which have served me just fine in the in the studies that I've done so far but I have been researching there's a pro version that has a little bit more beefier setup with some additional RJ 45 ports and in an 8 gig memory package what I find really interesting about this this board in itself is it can support all kinds of hardware it can support these these dual PCIE media tech cards it can support up to three and two 4G 5G cellular cards it can support NVME SSDs it's got a dual 10 gig ethernet ports it's got four one gig ethernet ports and it can be powered by 12 volt adapter or an AC adapter

9:30it has also got a USB to TTL header and a GPIO output so there's there's a lot of features and different things that you know allow this to be extensible and and that's what really excites me so you know I'm looking forward to how can I develop this live in this bootcamp into into a bootcamp and and maybe do some more things with it so on the radar I've got quite a list of things that I'm interested in so things like free radius things like certificate services file server I've talked out over to american bandwidth about doing passpoint thinking about doing some some wire guard or tail scale stuff with it certainly cellular so you can build your own cradle point type device and I'm also like looking at things like UWB halo maybe some other type of GPIO type labs for it and then obviously like your black server type of thing and maybe using it for hyper or for

10:33speed test and things like that I think all of those would be fun and those are the kind of things people love doing in the labs so walk us through it you people came to the lab they had a bag as full of parts and tools uh what did they do on that the first hour or two that you had them working that sure so uh based on the recommendations that I got from the wlpc conference runners I really took the effort on to make this a very interactive setup for people and so when I looked at the at the the banana pie itself you know the first thing we had to do was disassemble our case and then we take you and examine the mainboard and we're going to do things like you know add on our fans and assemble our ssds and add in our network cards we're going to be applying you know thermal pads immediately connecting TTL headers we're going to be screwing in our coaxial connectors

11:35and mounting those we're going to be you know setting some tips switches and doing some equipment flashing and we're interfacing with these both on serial interfaces as well as ethernet interfaces and so there's just an opportunity if if you don't know you know all of those things you'll pick up something prior to this uh it had been quite a while since I'd really played around much with uh linux and it had been my first experience interfacing with uh usb to TTL and uh it was really it was really a good time just to just to get in and learn some new things and it really kind of reignited passion that I have for hardware deployments and hardware development and just you know looking at some some odds and ends and going what can I make this thing do and I and I think that resonated with me when I was going through playing with this hardware and I think uh the rest of my class really enjoyed it too as we were we're building things and and actually making you know something

12:39especially something that we could take with us and you know put on our desk at the end of the day and look at it and okay yeah we we did this thing we made this yeah one of the things I noticed light like you'd mentioned both for an AI came out to see you before the conference and one of the things we do with a lot of deep dives who teach the first time is we have them do a practice session with us a couple reasons one to give you a artificial deadline so you don't wait to the last minute not like people procrastinating or anything and the other is to give you a sample to see what it's like to go through one of the things I noticed that was very helpful and why other people might want to take your deep dive or bootcamp is even in the assembly process you'd done it before so there was some tricks that you could share with people get this specific socket use this tool put these sides in first uh now of course if you didn't listen I'm sure some of the people in your class tried it and then came back and went oh maybe I should have listened this thing's not fixing

13:43so how many how many people did you have in your class and how did that first assembly part go so we had uh initially I think there were 20 slated and I think that when the class ran we had about 15 because some of the folks were actually you know running the conference and doing some other things during the time um but 15 was it was a pretty good crowd um everybody seemed to go along pretty well at the class we walked through every step of the of the assembly together uh which is a little different than how I used to operate while I was in school usually when I was in school I would be the the kid to run ahead and and and you know just trying you know get to the end of the book first but uh for this class it really made sense for us to go together because we were able to uh help each other or give assistance and that that's one thing that I that I noticed uh which was really unique with my class uh you know I I'd have uh people sitting next to each other and one

14:44person would get a step figure out maybe somebody had a question and instead of asking me uh they worked together on this and so uh when I was originally designing the lab environment for this I had intended for this to be done like in a partner lab type of situation and as I start developing one material to try to to build this into a boot camp I definitely want the boot camp to run into more of like a partner pod type of situation because I want us to have different configurations on either side and I want us to to to build and run different things together so that we can work together to achieve something and so um definitely as I saw the the willingness and the eagerness of everybody to do it um I teased Ryan Tyson uh who was the only student by a problem uh because he was the salesman in the group with all the engineers and it turned out it wasn't his fault his his board wasn't detecting RAM um but you know it was it was a good time

15:48because we were able to to get through everything together on time in time and everybody walked away with a smiling face as far as I could tell so this oh by the way you mentioned two 10 gig ports are actually SFPs so you could hook them up to anything yeah it also it also has a a usba and a usbc that can power it so I mean it's a very very flexible unit and what it has like three yeah three sims yeah three sim slots yeah in the in the micro SD yeah um pretty hefty hefty hardware so I'm sure all those things you wanted to make it do it has the the hardware oomph to pull it off they didn't want to set it up as a client I mean I think something would be nice is to have one of the AP the other is a client and then test things like MLO I mean it's got yeah chips so that didn't happen in the class however when they were doing the Wi-Fi 7 school bus drag racing somebody brought it and used it as a client for the school bus drag racing

16:52and so I've been talking with a couple of friends of mine and I'm thinking I'd like to maybe get the pro version of this and get it configured and maybe we can get it to participate as actually a station as a as an AP in the school bus drag races if we host those in Prague this year I think it might be kind of fun to just to just to benchmark these against you know what some what some name brand hardware can do uh this year I think uh I saw somebody spike up to a 4.02 gig that's a shockingly high number in the real world and again like you said we called it school bus drag racing it's not what school buses are made for NAPs weren't made to have a single client try to go as fast as possible but we did have MLO STR version working and showing it up on the spec and which is kind of impressive to see a big 320 meg channel in 6 gig and out 160 and 5 gig simultaneously

17:55being used so the system does work it's obviously not all clients can do it and who's in the real world is going to use the 320 meg channel but it was fun yeah it's it's it sounds like a good time yeah so so I'm interested note so it can't operate as a client so we could use this as a tool to you know operate to borrow from Cisco terminology as like a workgroup bridge or something like that um so certainly if you're in a situation where you need a robust client um that can connect something that maybe is legacy and you've got like an old 11b radio or something like that this might be an option for you you know in your development work so um we ran into that a lot when I was in the medical field where we'd have legacy clients and there really wasn't a lot you could do and then when those you know 11b stations associate they they slowed on the the entire network around them so um do you know there might be some use cases for this in the real world uh I'd like to see

18:58I definitely would like to to also try to get these to uh service and extended service set instead of just a a basic service set so you know find a way to to get roaming working between um devices and then um another thing that's just near and dear to my heart is I really would like to figure out um how how could we set a few of these up around the edges of a room and maybe get some UWB going and build some location I think that would be uh pretty cool I I don't know how we're going to do it yet but uh I've got maybe six seven and once to figure it out it's a good start to head that direction well we've talked about the hardware let's now talk about the software side you chose to go with WRT which has been around since uh if anyone has a long memory the blue link system devices or actually called WQ54G's um yeah that's now and that was been a worse program tell us why you chose that and what features it has that you used in class

19:59well so um to be honest with you Keith I chose it because it was available uh and and we knew that we knew that it would work uh and it and it and it had some limited support um so it wasn't the official uh version that they you know they have like a a WRT you know specific device that they that they have for this um uh we didn't go with that build but we did choose uh open WRT and I think we're running I get a double check the version but I think it's something like 24.10.5 which was released in December um so we went with head because I knew it was supported and again I want to people to walk away with something that they could take with them and it would be okay to use and it would update and it would be more or less as secure as the other things that are out there um so so that was really good for us um what features we used um well certainly we used the the wired wireless uh land configuration tools uh there's an integrated firewall that we

21:01didn't get into on uh this course of labs although I was uh in the process of building another lab where we could do something like a point-to-point VPN tunnel so that's in the works for sure for our next thing um also you know we should have the ability to load uh like uh you know third-party software and there's something like like a wired ever something later on down the road uh obviously there's an integrated DHCP server that we were using uh there's a broading capabilities that we didn't get into yet um there is uh storage capabilities that uh unfortunately not all of our students could take part in because our NVMEs did not arrive however I did have one student who uh was able to take the NVME lab and port that so that they could connect uh USB drive is attached storage and it a matter of minutes uh to their device and so already in class uh we we did see you know people were already coming up with uses um we had another guy

22:06that was able to uh install TCP dump and so now you know his is operating as a sniffer in class so it was just it was incredible the the speed at which uh our my my students were you know picking up and coming up with new inventive ways to do things and and really just kind of pursue this to uh you know different depths than I had even intended uh it was it was exciting to see well do you mind if we share on the show notes uh parts list that you had in your class yeah sure that sounds great well as Adam the show notes and people can download it yeah absolutely in addition to just the the kit that came with the device and the case and the power supply and all the antennas you added a USB to TTL and what was that used for? yes so the USB to TTL header that device came with my kit and I don't know if it came with all the kits um but that's a really cool device where uh you plug in a USB stick and then it has uh three

23:10headers on it an RX the TX and a ground uh you swap the RX and the TX uh on one side you know to the other side so it's a four-and-a-cross over and now you've got uh direct serial console access into the hardware and so uh i custom strips some long cables from my students so that they could have a a nice long serial cable uh in the event that they were working on these things on their desks that's the one shorter coming uh that i would say that i had with my hardware package when i ordered it was the header pins where we're just uh the the little working cable there was a little short so i went ahead and ordered my class some some extra cables for that and and those are available for a very reasonable price as well uh and key that can i can email you the information for those parts as well we'll just add those on there i'll also add in addition to the that you know the parts that were used in your class just some screenshots of what's involved in the hardware so you can see the actual hardware setup itself what other labs do you

24:12as you mentioned some new labs in the future anything unique that you think you could just use this for i mean you mentioned a VPN on one end a client side the work group bridge and nas ghp dns servers yeah you know one thing that i really liked was uh your idea about taking this with you to what say like a hotel and being able to have your own secure Wi-Fi that you could uh you know run this device as a client and then you could either plug into it physically or you could just host your own ssid from it being that it's got private entry radio configuration and you could you know easily pair to a hotel network and five or six gig and host your own five or six gig cell directly from it and have you know really good secure service in your room uh especially with the VPN option we'll have to get you in touch with markouts and see if we can merge the since it can carry a cell board on board

25:12kind of merge those two deep divers together yeah we'll see um i would be very interested to see what we can do um very interested in cellular myself and uh spent a party bit of time trying to learn the technology so but very excited about all the all the all the all the the Wi-Fi technologies but but also you know what else goes with that you know as well as engineers so i think um certain leaders there's there's plenty of spectrum out there to learn about well thank you for your time today sharing the your knowledge and how you developed the deep dive and kind of what's in there we will be offering it in Prague for anyone who wants to you know in the european side who wants to come in enjoy the process Brad how would someone find you if they wanted to track you down on the inner webs yeah sure i'm at uh linkedin uh under my name Bradley Wagner you can also uh shoot me an email over at uh four six four at extensible wireless dot com you can listen to another episode of heavy wireless part of the packet pushers podcast network and we were talking

26:15about a banana pie but this being used as a build your own a p is part of wopc's deep dive if you have any other ideas for other topics you'd like in the future feel free to leave them on the pack of pushers website thank you and we'll talk to you in the next episode