I am a bit confused when it comes to networking. So here is my issue.

My landlady has 3 Airport Extremes. Two of the latest and one of the previous generation. Current one, latest, is plugged into a Frontier provided DSL router. The Airport is in bridge mode and everything is working fine, from what I understand.

When we get cable internet, Atlantic Broadband. I can not use my personal cable modem. Which will effectively not have to me put the Airport in bridge mode. As it’s just a modem.

That much I know. What confuses me is some people say I can put the Airports in bridge mode, as they are now, even with the cable modem/router from AB. But others are saying that AB needs to put their modem/router in bridge mode.

What is the difference between the modem/router or the Airports in bridge mode? What are the benifits of either set up?

Also I want to make it easy for my landlady for when I leave. And AB sends a firmware update and basically wiped the modem/router’s settings. Therefore putting it back to normal mode and ruining the set up.

She is looking into getting telephone on with the cable internet. And the fact AB states that their modem/router is Moca enabled for the new TiVo stb. Which is probably why my personal cable modem wouldn’t work.

KOT

KOT,

A "modem" is simply an interface between the cable in the street and a network connection. Unfortunately, this network connection can only support a single computer. While this might have been OK at the dawn of home connections when a person owned a single computer, this does not work out very well in a modern context. Currently, a "simple" home network could have dozens of devices connected. (cameras, computers, pads, phones, thermostats, media systems, TV's, Blu-ray, games, and on and on.)

One follows the modem with a "router". The router can split that single connection and support multiple devices on the local network. Inside the router is a "DHCP" function that manages this splitting process. It is customary to include other, security related functions inside the router box, but we don't need to discuss them here.

If one wants WiFi, an "access point" is added to the local network. The access point manages the WiFi. It is possible to roll all three functions into one box. Unfortunately, this box is commonly called a "router". When a person mentions "router" it is not obvious exactly what is inside the box. Cable companies are beginning to call their box a "gateway". Gateways provide all three functions -- modem, router, and WiFi access point.

An access point can service a limited geographic area. Multiple access points can be used to cover wider areas. Your Airports contain a router and an access point.

As you can imagine this DHCP function is a take charge sort of guy. If there are multiple DHCP servers active on a local network, the result is chaos. "Bridge mode" turns OFF the DHCP function, In your case placing an Airport in Bridge mode, converts the Airport to a simple access point. Multiple access points are welcome, multiple DHCP servers are not welcome.

It is OK to have DHCP servers in series. Actually, your home router is a DHCP client on the ISP's network. Obviously, there is a difference between serial and parallel connected routers because your local network devices are not available to your neighbors. On your local network you should not attempt to connect routers in parallel -- unless only one DHCP server is enabled. Consumer routers with their DHCP server disabled function as access points and/or network switches.

If you connect multiple DHCP servers in series, local network clients will be able to access the Internet, but they will not necessarily be able to access local music servers and such. (If the same DCHP server is being used by the both clients, it probably will work, but clients using another DHCP server will not work) For portable devices "work" or "not work" could depend on which access point is in use.

If you connect DHCP servers in parallel, you'll have a chaotic situation. Things could never work or work perfectly for a while, then collapse, only to start working again a day later.

---

With respect to your landlady: Likely, she'll have a very simple network after you leave. If the Atlantic device is only a modem, one of the Airports must have it's DHCP server enabled. Typically, one would enable the Airport that is directly connected to the modem and the other Airports would be wired to the first Airport. If the Atlantic device is a modem-router-access point you must be more careful. The most bombproof setup for your landlady would be to force the Airports into Bridge mode.

You'll get flack for doing it this way because many of us hate Airports and there are some subtle performance considerations, but you'll be safe from ugly  potential issues if an Atlantic firmware update terminates its Bridge mode (if this mode is actually available).

If you use an Airport DHCP server, make sure that you don't attempt to use the Atlantic's WiFi and that only a single network connection is made to the Atlantic device.

As I have posted several times since I found out, from AppleCare themselves, "Apple neither recommends nor supports more than two Apple network devices in the same network". It took more than ten years to tell me this, but......

If you're using the Airport Extremes as access points, set it to Create A Network and disable NAT/DHCP. If you're using one as the router, give up and use something else. It's such a PITA to try to limp along with these that it's not worth doing and I'd like to know- why the hell does she have three Extremes? That's a waste of $600 and it still sucks.

I applaud you for taking the time to make the lengthy post.

However it is not accurate.

The DHCP server does not perform the routing function - that's the job of a router.

Granted these multi-function boxes often contain a modem, a router, a DHCP server, a firewall, a wireless AP, a small Ethernet switch and perhaps more.

But it need not be that way - they could all be separate devices or any mix in between.


The only part needed for connecting multiple computers to the modem is a router.


The DHCP server CAN hand out unique IP addresses to each computer but that is not a necessity.

Each computer could have a unique static IP address and it would work just fine.

It's also quite possible to have the DHCP server in another physical device, not the "all in one".


When NAT is mentioned that has to do with the router function.

If you have one router feeding another you have a "double NAT" situation which you have likely heard of.

Heck you could have a "triple NAT" setup, not that it would be a good idea.

The "bridge" mode you hear about usually has to do with turning off the router function in one device so you avoid the double NAT situation.


There is more I could write about but it's time for lunch and I'm hungry.

Frederick

I was suckered by the first sentence and thought that a 101 version would help you and others.

Bottom line -- ditch the Airports. In the long run they are more trouble than they are worth. But, they occasionally work.

Should I delete my post?

Of course not. Thank you for taking the time. Lots of good info, Frederick’s hair splitting notwithstanding 😀

The reason for the Airports, is because I have used them in the past and already had the 5th gen AP. I purchased two 6th gen, which the seller labeled them as Airport Express, thus got them both for $126 shipped.

But in all honestly, I really wanted to purchase Linksys Velop 3 pack. But didn’t want to spend the ton of money... though a month’s rent off would’ve been nice. Ha

This house is 3 stories high and probably 1,000 sqft per level. The modem/router is located on the 2nd next to the front wall... so the 3rd and bottom level gets crap single.

Heck, I had my Mac connect to the WiFi and pass through the internet to the Ethernet port to my AirPort Extreme that I had, 5th gen. So my wireless devices could connect too. Even my Mac struggled with the WiFi. And an other tenant kept on getting kicked off.

But since installing the APs, all is well. No one complains about being kicked off and such.

And now that I have access to the set up menu. I can see over 15 to 20 devices connecting to the AP. Of course not all 20 are on one AP.

She just has to call AB to get cable internet... DSL just does not cut it.. 5mpbs is kinda slow.

Thank you for yall’s help. I guess leaving the AirPort Extreme in bridge mode is the best bet for when the cable modem/router comes in. Hopefully soon...

KOT

Hair splitting?

Attributing routing to the DHCP server is unequivocally wrong.

They are two fundamentally different processes.

And to my way of thinking handing out wrong information is not something folks here want to be doing.

In theory we are paid to know what we are doing. Yes? No?

Frederick

I would say that most of us here know that DHCP doesn't handle the routing but, I am assuming, that Buzz untended to "dumb down" the verbiage to make the explanation easier to digest. Especially when it came down to trying to explain using the ISP router vs the Apple one in a Double NAT configuration.

NO. Any time ANY of us write so clearly about these topics, the posts should be kept. The added comments only made your post more valuable since they corrected some things that were stated, as you said, in a 101 version.

Several books have been written about this stuff, but sometimes a person's brain, especially if that of a beginner, can only handle a brief outline.

Synopses for Synapses, I say!

I made one line bold because knowing that at least one MAC computer is being used should have been mentioned in the first post.

I wrote about an iMac that would constantly connect to the Airport Extreme that was in the basement, even though its SSID had been removed from the computer. The other AP was 20 feet away, but it would always try to connect, with poor performance. I don't remember who made the comment "Apple devices leave claw marks when they let go of a network", but it's damned accurate.

I also wrote about 'The place where WiFi goes to die'- that one had several Airport Express, an Extreme and a Time Capsule, which was acting as the router- the Expresses and Extreme were set up as APs, with NAT and DHCP disabled. If the Extreme was in the network, the wheels fell off completly and as soon as I disconnected it, all was well in the kingdom.

If problems arise again, disconnect one AP at a time and see if the problem stops.

There was no need for me to mention that I was using a Mac on the network. Solely because my question was about using 3rd party WiFi routers, which happened to be Apple AirPort Extreme, plugged into an ISP provided “gateway”. What were my best options for set up. Keeping in mind that I wanted to leave my landlady with the ability to leave it alone for when I leave. In other words, she wouldn’t have to call Atlantic broadband and ask them to put the gate water into bridge mode.

KOT

It sometimes happens that we think we don't need to mention something, but when we finally mention it, the situation is seen differently and a different solution -- or sometimes just THE solution -- becomes apparent.

My signature doesn't ask for some model numbers to be mentioned, but all of them, because I found out years ago that when we don't understand what's going on, we're not qualified to decide what information to omit for brevity. Highfigh's answer might be, or might have been, the key to your entire situation! If not, no harm. If so, another problem was licked a bit earlier through knowing all the models involved.

Ok, let me explain.

When I moved in. She had an ISP provided WiFi router, which was connected to DSL. And located on the south outside wall, second level

She provided me with the password on my phone and it promptly connected while I was outside.

As soon as I went to my apartment, which is located on the first level on the north side of the house. I lost connection.

Soooo. I was able to connect my computer, which happens to be a Mac. And I already had an AirPort Extreme 5th gen. So I forward the internet connections from the Mac’s WiFi to the Ethernet. Connected my 5th gen AirPort Extreme to the Mac’s Ethernet. Created my own WiFi for my apartment for my wireless devices.

Now after I received two 6th gen AirPort Extremes. I connected one of them to the ISP provided router, put the AirPort in bridge mode. Then used the second to extend the WiFi network as well as my 5th gen AirPort.

So this house went from a signal WiFi AP on the south wall on level 2. To three WiFi APs. One at the original south wall 2nd level, the main. One on north side, about 15’ from the north outside wall and centered from east and west on the 3rd level. And the third on the 1st level centered between the east and west and 15’ from the north wall... basically a straight shot down from the 3rd level’s AP.

And since I have access to the connected devices. I am seeing on average of 15 to 20 devices connected overall of the 3 AirPort Extremes.

So my original question was to leave the AirPort Extremes in the current bridge mode. Or change the ISP provided modem/router into bridge mode and default the AirPorts into giving IP addresses.

Currently, the set up works great. No one has complained about dropped connections and such. However, the ISP provided AP is from Frontier and it’s DSL. She is really wanting to get cable internet. Thus a change of providers and a change of modem/router. Hopefully the new ISP provided modem/router will allow a plug and play of the AirPort Extreme, which is in bridge mode.

Basically I want to provide my landlady with a simple system for when I leave. I don’t want her to call the cable provider to have them put their modem/router back into bridge mode after a firmware update, if one ever happens.

KOT

Typically, the ISP’s Gateway will not default to Bridge mode and this is what we are afraid of. There is some risk that an ISP firmware update or a support person attempting to fix something will cancel Bridge mode. If your setup depends on the Gateway being in Bridge mode, you’ll get a call. The amount of damage, if any, depends on what kind of special services you are using. Online games, remotely accessed cameras, VPN’s, control systems, and such, are at risk. A Sonos system will likely get into trouble.

A least in my area some of the ISP support desk staff will notice that a Gateway is set in Bridge mode and they will respect this. They’ll then suggest that the customer contact the person who enabled Bridge mode for further troubleshooting.

Comcast is scaring me because they are sending out new Gateways, asking the customer to self install the new arrival. Mercifully, the Gateway setup procedure will ask for and set the SSID and WIFi password, sparing the customer from digging through the Gateway’s administration pages, but there is no attempt to preserve any settings from the former Gateway before it was disconnected. This will work only in the simplest of setups because any custom settings from the old Gateway will be lost. The new Gateway will not be in Bridge mode. Further, some of the Gateways cannot be set to Bridge Mode from the user side — one must get to a support person, who understands what Bridge mode means, to do this. One support person claimed that his console was not authorized to place the Gateway in Bridge mode. Most of the current Gateways have a Bridge checkbox on the Admin landing page. In this case it’s Login, click, Accept, (optionally) logout, done.