What if you use Apple AirPort with external non-Apple DHCP? Can you use AirPorts in bridge mode of a /23 network while still supporting UDP broadcasts and roaming without additional configuration?

@Etan yes you can be happy in bridge mode (setting aside whatever /24 or /21 you end up choosing)! See my answer with specific recommendations for hardware to complement your Apple wireless access points.

There's no such thing as a network with a /23 mask bit. The hard limit is 256.

@bmike Routing UDP packets is "doable" but not advisable - it introduces a DoS problem. The proper way to do it is via UDP Multicast.

Not sure if it's a Multicast or a Broadcast (we use this setup at a medium sized LAN party, primarily focused on Hearthstone. As I understand it, I could get everyone in a /23 IP range, but the broadcasts will still only be sent to those in the same /24 subnet? Why are there class B / class A networks, if there is such a limitation? What's the difference except a larger IP block?

@user3439894 - that's using CIDR (classless subnetting). I am referencing network classes.

Even if you use a CIDR (classless supernetting), you will still have two subnets as I described in my answer. There is no IP address that goes above xxx.xxx.xxx.255

@user3439894 - thus my answer as it is written.

Allan - you have a superb grasp of the issues at hand. +50 Knowing how things work under the hood is crucial for happiness - the real fix would be to keep all the devices you need in the same /24 - put all the IOT crap, wireless cameras, network enabled scales, etc... on another WiFi network entirely.

It's players at a LAN party. Expect a phone and a laptop per player. Even with only 150 players you are already over 300 IPs. Unfortunately, having to understand everyone that there are two WiFis for gaming and for the phone is not practical. Assuming it's multicast (not broadcast), will it work with a /23 with an external DHCP and all AirPorts in Bridge mode? What about roaming? Is roaming standardized or something that has a vendor-lockin attached?

Backatcha @bmike - one of the most knowledge one on here (and IRL)...Anyway..with latest comment, this is a much bigger and complex than the initial question...

Here is the LAN party history - welcome back Etan! apple.stackexchange.com/questions/211298/… - I would set up a network for just the players and keep everything else off that subnet. That way you don't have to invest in expensive routers. Do everything you can to avoid breaching 300 clients on the main network would be my advice.

Hi @etan. I'd say - main chat room is best - mind if I push these all to the main room?

@Allan Hi - same question - mind if I put these in the main room?

:)

No, just having an option to discuss the topic would be nice. Not sure if it's still Apple specific though (if possible, I'd like to remain with AirPort as they are very easy-to-use and proved to work well and reliable)

So yeah, if you think main room is the way to go, go ahead :)

So, right place now? :)

chat.stackexchange.com/rooms/38/ask-different-chat <-- is this the main room?

Is this the main room?

- Roaming should work regardless of network size or vendor?

But yeah, let me know once you got a few mins @bmike – want to be sure I know what I need to buy :)

@bmike - sure!

@Etan - just to answer you 3 bullet points:

Hi @a

- UDP generally works on one subnet

OK, and subnet is always /24?

Or can I increase to /23 with other equipment?

(e.g. class B network)

← 30 messages moved from Discussion on answer by Allan: Creating a network larger than 200 IPs

:)

This is what I don't get yet ^^ where does the /24 limitation come from

The /24 is called a bit mask

/24 == 255.255.255.0 isn't it?

24 1's followed by 32-24 0's

what that means is it is the length of the subnet mask...24 bits

Yes.

But why do multicasts / broadcasts stop working if you go beyond 24

isn't the "subnet mask" the way to say how large you want your network?

Hang on....we have to get on the same page....

:) sorry, I think I got something confused at some point xD

So, each part of the IP address is an octect xxx.xxx.xxx.xxx is 4 octetcs (8 bits). The /xxx is the bit mask - meaning how many bits are not used (there are 32 bits). /24. So, this means your IP address will be xxx.xxx.xxx.y (where Y is the range from 0-255).

When you use the /24, you are basically "turning on" the first 24 bits:

yup

Ooops...I meant to say 24 bits

not 32

yes

and with /23 you have 1 more bit, essentially doubling your ip address pool

so.../24 = 111.111.111.111 (not IP, but addresses)

huh?

11111111.11111111.11111111.xxxxxxxx

the ones are the mask....

this should be /24

(in binary)

but yeah i get that

correct..I'm typing too fast and not paying attention.... it's 8 bits.

ya. and with /23 it's 9 bits :)

11111111.11111111.1111111x.xxxxxxxx

but you can't have 9 bits in an octet.

Why does it need to be in an octet

Do multicasts / broadcasts only send to 1 octet?

Because the IP address is based on octets - each value is an octet.

IP is just 32 bits

I know that /23 nets exist ^^

the largest value for 8bits is 255. This is why you can't have more than 254 IP's on a single subnet

To get more than 255 IPs, you need another sub

Why can you have netmasks of 255.255.254.0 if a subnet can only have 255 IPs

Sorry if I don't get this right ^^

never heard that IPs are 8-bit block based until now (except for the popular method of writing them down)

ok..I can't work in machine gun fashion....

i don't even know what question I am supposed to be answering now...

Sorry ^^

<#

<3

The question is

If I have a DHCP for a 255.255.254.0 subnet (i.e. /23)

And someone (let's say 127.16.0.42) sends a broadcast

Will the guy at 127.16.1.35 receive it? :)

Or is there an additional limitation in place that limits broadcasts / multicasts to networks up to /24 of size.

If you configure your network with a netmask of 255.255.254.0 both those address will be on the same subnet, so yes.

So if I buy 1 of these edge routers, configure it to use 255.255.254.0 as subnet => connect 8 AirPorts in bridge mode, everything should be fine?

If you buy an Edge router, configure a your NETWORK as class B with a 255.255.254.0 netmask then it should work.

If you are going to go forward and get the Edge Router from Ubiquity, I would get the multi channel APs as well.

hm

and by multi channel, I actually mean simultaneous dual band antennas.

How many clients does one of those APs handle?

I thought that the AirPorts are quite nice, with beamforming and mimo and whatever

Airports ARE nice. They are fantastic devices. However, based on the requirement of it being a "lan party" for more than 300 clients (devices) you are no longer in a "small network"

You will want something centerally managed.

centrally

hm kay

Beamforming is great if you are going point to point, but with a diverse base of devices, beam forming won't give you that much.

I'll have to upgrade this over time.

Sounds like next step to me :)

Can I use 1x ubiquiti AP and 4x AirPort, and roaming will work fine – or will there be issues?

i.e. do I need to replace everything or can I start using more professional products over time

You can mix in the Ubiquiti AP's without getting rid of your AirPorts.

Grow as you need to.

OK

So, the first step is

- Edge router with a sufficiently sized NAT table for 510 clients

Now..there is no set number of clients an AP can support simultaneously. Depending on what you are doing you may need more or less than the 50 clients quoted earlier. I can't say until I see the traffic

- Setting the AirPort to DHCP instead of DHCP+NAT and have each airport assign a certain portion of the available addresses

Yes on the router....

The NAT table should be more than sufficient

The AirPort should be set to bridge with DHCP forwarding (if necessary)

Should I use "Bridge" or "DHCP only"?

Bridge. Let the edge router handle the DHCP

With "DHCP only" I think I could get an advantage if the wifi breaks somewhere. So I can check what his IP is and see immediately the access point he's connected to

imagine AirPort 1 => 127.16.0.0 ... 127.16.0.0.63 AirPort 2 => 127.16.0.64 ... 127.16.0.0.127 etc

Is there a reason for Bridge over "DHCP only"?

I think your adding in complexity...I've never had DHCP break on me. What I did have (managing over 10,000 devices) was failover DHCP

OK

Remember, the more config you have do on each device is more complexity and potential failures you add to your environment.

I still have to config each AirPort to create the same wifi network, or is there a way that I can push the configuration to them remotely too?

That, I don't know. I never did enterprise deployments with consumer APs

xD

How hard are those ubiquiti routers to configure?

I don't know if this is a business you are running or just for fun..either way, your bread and butter basically comes down to user experience and if the network goes down or performs badly, UE is in the tank. This is where you want to get good stuff.

It's for fun :) So far, no network issues with the AirPorts

We had network issues with the ISP modem in router mode though

The UBI equipment is very easy. It's more complex than a AirPort, but not so much so that you need to get a degree.

Putting ISP modem in bridge mode, then DHCP+NAT on first AirPort + 3 Bridge AirPorts == perfect all the time

The AP's are really nice...two versions: LITE and FULL. LITES are cheaper but can't stand on their own - the need a controller. The FULL can stand on their own, and can convert to LITE later down the line.

BTW => IPv6 noob question. Do I need to do anything for IPv6, or does this work out of the box?

Works out of the box.

Ubiquiti sounds like it's aimed at the small business sector – like the AirPorts as well. Is that correct?

Hm. also have enterprise products

Focused on SMB market - 50 to 1000

airport is consumer / SOHO market or 1 - 50

I wonder why large instituions like schools etc use AirPorts

Without any affiliation => what are the big players in that market? any pros / cons? Also interested in global availability and support quality

Don't know. Everyone that I have ever consulted for had difficulty with them...but they loved them

Cisco? Good stuff, expensive and you need service contracts.

HP is complicated as hell.

I like at the AirPorts that you can confgure all 4 of them at the same time using the same tool instead of having to remember IPs of all browser pages

another good player is Rukus. I have used them before, but they can be complicated.

okay, so Cisco / HP / Rukus probably 1k-10k market xD

yup.

What happens if you put PoE into an AirPort? Does it just work like before or do I need to pay attention to plug these into non-PoE ports?

PoE is a God send. If you put a non PoE device on a PoE port, nothing happens.. it works normally. It's just a waste of a PoE port.

I run PoE in my house, it's that good. No more wall warts.

Good to know.

Ubiquiti lists the routers with certain amount of PPS – how can I know how much I need?

ah, seems like they have some software that makes it visible

hmm. poe == prize * 2

Well, thanks for the help anyways <3 And thanks for the patience :)

Will check out the different products