Somebody 'Splain Me DHCP Settings

[j44ke]

I think I am getting some unnecessary network collisions on my stupidly simple and likely redundant home network. I have an Arris modem that I have set up as a DHCP/NAT server. I have connected two ethernet cables to that modem, one running to my desktop and one to my wife's desktop (well, to an ethernet switch that is connected to her desktop and her law firm's secure VOIP/data doohickey.) I have also connected the modem to an Airport Extreme set to Bridge Mode. That provides the WIFI in the house, connects the music system and laptops, iPads and iPhones to the InterNets.

I used to run the Arris in Bridge Mode and then have the Airport Extreme do the DHCP and NAT, but the ethernet connections were only getting 100mbps whereas with the Airport Extreme in Bridge Mode, the Arris doing the DHCP and NAT, and the ethernet connected directly to the Arris ports, the speed is 300-350mbps. That makes for pretty terrific quality streaming of bike races. And the secure VOIP/data actually works.

My question is whether I need to shut off (not that I can figure out how to do this as the options do not include "Off") the DHCP on the Airport Extreme (not that I know how to do this as the options do not include "Off") or if that even matters. Also each computer (all Apple) has a section of Network Preferences that says "Configure IPv4 using DHCP" which I assume is not the same as the DHCP that the Arris modem does. There seems to be a lot of DHCP going on, and when my wife and I are both working online, there are multiple minute (2-3) pauses or freezes that can be frustrating for my wife. And me. But mainly for my wife.

As you can probably tell, I know only enough to get everything wrong. Which is why I am asking here.

[EricKeller]

I don't think DHCP is causing your pauses, it's quite possible it's upstream from your network. You should be able to set how often leases renew, "never, is never good for you?"

[ericpmoss]

I don't think DHCP is causing your pauses, it's quite possible it's upstream from your network. You should be able to set how often leases renew, "never, is never good for you?"

Ah, my favorite New Yorker caption. Not enough managers appreciate its incisive wit.

[j44ke]

I don't think DHCP is causing your pauses, it's quite possible it's upstream from your network. You should be able to set how often leases renew, "never, is never good for you?"

Ah, my favorite New Yorker caption. Not enough managers appreciate its incisive wit.

My wife, an attorney, has this framed in her office.

Ok, so not DHCP. I'll check the lease settings. Actually hadn't thought of that.

[NYCfixie]

I think I am getting some unnecessary network collisions on my stupidly simple and likely redundant home network. I have an Arris modem that I have set up as a DHCP/NAT server. I have connected two ethernet cables to that modem, one running to my desktop and one to my wife's desktop (well, to an ethernet switch that is connected to her desktop and her law firm's secure VOIP/data doohickey.) I have also connected the modem to an Airport Extreme set to Bridge Mode. That provides the WIFI in the house, connects the music system and laptops, iPads and iPhones to the InterNets.

I used to run the Arris in Bridge Mode and then have the Airport Extreme do the DHCP and NAT, but the ethernet connections were only getting 100mbps whereas with the Airport Extreme in Bridge Mode, the Arris doing the DHCP and NAT, and the ethernet connected directly to the Arris ports, the speed is 300-350mbps. That makes for pretty terrific quality streaming of bike races. And the secure VOIP/data actually works.

My question is whether I need to shut off (not that I can figure out how to do this as the options do not include "Off") the DHCP on the Airport Extreme (not that I know how to do this as the options do not include "Off") or if that even matters. Also each computer (all Apple) has a section of Network Preferences that says "Configure IPv4 using DHCP" which I assume is not the same as the DHCP that the Arris modem does. There seems to be a lot of DHCP going on, and when my wife and I are both working online, there are multiple minute (2-3) pauses or freezes that can be frustrating for my wife. And me. But mainly for my wife.

As you can probably tell, I know only enough to get everything wrong. Which is why I am asking here.

Are you sure the law firms do-hickey is not also providing DHCP services (Dynamically handing out IP addresses)? Having two DHCP services running on a home network (in a corporate network there are settings that can easily make this happen for redundancy) can be problematic if you create loops with cables.

I'll check my Airport Extreme when I am home about "bridge" mode. Mine is setup like this: coax cable => FiOS router, DHCP => Airport Extreme, NAT => cables to laptop and wifi to AppleTV, iPads, etc

The computer message "Configure IPv4 using DHCP" is what you want. The Network settings are telling you that it is waiting for a "Dynamic" IP address from the DHCP server (Arris modem) and that you have not "statically" assigned it an IP number.

[EricKeller]

I'm not sure why you wouldn't just run nat on the airport. I have two routers daisy chained in my network and there is no confusion there. I run an FireTV throgh this, and it works great, even though there is an intervening 10mbps switch. Yeah, if there was potential for loopback it would be bad, but the airport is going to grab any dhcp requests from the devices associated with it. I could see in some greedy wireless setups this might cause a problem if there were multiple routers. Just set the airport to give out addresses on a different subnet than the modem gives out.

[NYCfixie]

I used to run the Arris in Bridge Mode and then have the Airport Extreme do the DHCP and NAT, but the ethernet connections were only getting 100mbps whereas with the Airport Extreme in Bridge Mode, the Arris doing the DHCP and NAT, and the ethernet connected directly to the Arris ports, the speed is 300-350mbps. That makes for pretty terrific quality streaming of bike races. And the secure VOIP/data actually works.

Do you have an older Airport Extreme? The older flat ones that are similar to Mac Minis only had 100mb. Newer ones have GB.

If you just want to simplify your life and get better WiFi speeds....upgrade my friend!

1) Cable from wall connects to...

2) Modem in bridge mode connects to...

3) Airport Extreme for DHCP/NAT
=> Wifi AC and N => all wireless devices
=> GB wired => all wired devices


It just means giving Apple more of your money.

[NYCfixie]

I'm not sure why you wouldn't just run nat on the airport. I have two routers daisy chained in my network and there is no confusion there. I run an FireTV throgh this, and it works great, even though there is an intervening 10mbps switch. Yeah, if there was potential for loopback it would be bad, but the airport is going to grab any dhcp requests from the devices associated with it. I could see in some greedy wireless setups this might cause a problem if there were multiple routers. Just set the airport to give out addresses on a different subnet than the modem gives out.

Exactly, if you know how to configure routers with different IP ranges and know how to configure DHCP servers with different scopes than no problem. The average home user does not (no comment on the OP's tech abilities).

The easiest solution is a newer Airport Extreme. If you are a windows based home than get a Linksys (or similar) router and configure it for DHCP and NAT. But whatever you do, DO NOT use cable/TV/provider supplied devices as your main protection and services because they usually suck and have limited functionality so users do not screw them up.

Did you know that many companies now use your home router/modem to offer bandwidth to others ion your area without you knowing it? How do you think all of these hotspots have been popping up recently? Another reason to shut off all services in provider equipment and set them to bridge mode. Save your bandwidth for yourself.

[j44ke]

I used to run the Arris in bridge and the Airport Extreme as the DHCP/NAT. Made sense privacy-wise. Admittedly that was when I had the previous iteration of the Airport Extreme, which I retired last week - I thought that was gigabit too? Now I have the newest Airport Extreme and because the old one suddenly kept dropping connections. So with the new one, I switched over to the Arris doing all the NAT/DHCP and running the Airport Extreme as a bridge. My desktop and her desktop are plugged in directly to the Arris, while everything else in the house is running on WIFI into the Airport Extreme.

I'll see how this runs with the extended lease settings, but I might switch back to the bridged modem with the AE DHCP/NAT. I've been warned about a potential all-nighter tonight, so I'll get the dependability report in the morning.

edit: The advice on using a different subnet for the AE - I remember getting that advice before. Good reminder. And yes, my provider is famous for co-opting bandwidth. Right then, my head is clear now. I'll see if I can work this out quickly before tonight's impending marathon.

[deadbeef]

If you have the newest AP Extreme (looks like a pedestal rather than a tiny pizza box), it should have GigE ports on the back and not have any problems pushing data around in your setup.

I have a Motorola something-or-other cable modem setup as a bridge to my Time Capsule (also the current pedestal style), with the TimeCap doing all of the NAT/DHCP duties, and it works really well on my 70-ish MBit connection.

[NYCfixie]

I used to run the Arris in bridge and the Airport Extreme as the DHCP/NAT. Made sense privacy-wise. Admittedly that was when I had the previous iteration of the Airport Extreme, which I retired last week - I thought that was gigabit too? Now I have the newest Airport Extreme and because the old one suddenly kept dropping connections. So with the new one, I switched over to the Arris doing all the NAT/DHCP and running the Airport Extreme as a bridge. My desktop and her desktop are plugged in directly to the Arris, while everything else in the house is running on WIFI into the Airport Extreme.

I'll see how this runs with the extended lease settings, but I might switch back to the bridged modem with the AE DHCP/NAT. I've been warned about a potential all-nighter tonight, so I'll get the dependability report in the morning.

edit: The advice on using a different subnet for the AE - I remember getting that advice before. Good reminder. And yes, my provider is famous for co-opting bandwidth. Right then, my head is clear now. I'll see if I can work this out quickly before tonight's impending marathon.

I always like having two hardware devices, properly configured, between me and that sewer they call the Internet.

On a related note, I just passed my 6 hour certification exam yesterday, (only took me 4 hours) so I hope I am giving you good advice:
CISSP® - Certified Information Systems Security Professional

[j44ke]

Okay, everything now is running through the Airport Extreme "tower" with the modem in bridge but with its firewall (whatever that's worth) on. All the wired connections seem to be more stable than they were in the other configurations actually, so that's good. The WIFI got wonky in the most distant part of the house though, so I redid the WIFI part of the network, putting the "retired" Airport Extreme between the Extreme tower and an Airport Express that runs our music. Now things work perfectly on both ends, at least until the Airport Extreme croaks. It started buzzing somewhere inside for some reason, and I don't think it has a fan, so I figured that was not good. But now it isn't buzzing at all and signal seems steady and strong. Eh, what the hey. For now, good enough.