Extreme slow speeds lan and wireless Time Capsule

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Level 1

9 points

Extreme slow speeds lan and wireless Time Capsule

I have an Airport Extreme 3G Time Capsule with version 7.7.3 firmware that I use for lan/wireless connections and backup of all apple devises that are not using the cloud. For the last month or so sometimes I get ridiculously slow speed issues that cannot be remedied with any one fix that I have tried. Speed checks at my i mac or via wireless on any device at any location show speeds half of what I am paying for. If I pull a speed check at the back of the modem everything is ok. If I pull a speed check at a port on my Net gear Pro safe FVS318G with the Airport extreme disconnected the speeds are fine. But when the time capsule is used the speeds are slow. This doesn't happen all the time. In fact this am everything was fine, it just started about an hour or so ago again. And it normally clears up in a few hours on its own. Its like someone is inside my computer slowing everything down I cannot even do a backup on my i-phone when this is happening. I bought the net gear thinking that the triple nat might help I'm not using the vpn option. I'm lost and open for suggestions?

My i mac is running El Cap v 10.11.4.

Att Uverse 18m 1m

Time capsule a couple years old.

Speed check 1-6m down when issue happening, 17-18 when good. upstream effected also.

iMac (21.5-inch Mid 2011), OS X Mountain Lion (10.8.4)

Posted on Mar 31, 2016 1:31 PM

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Answer 1

Loner T

Level 9

59,536 points

Mar 31, 2016 1:33 PM in response to robx57

Can you please describe the topology of your network?

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Answer 2

robx57 Author

Level 1

9 points

Mar 31, 2016 1:39 PM in response to Loner T

Modem-Netgear-Airport extreme-everything else.

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Answer 3

Tesserax

Level 10

158,088 points

Mar 31, 2016 2:11 PM in response to robx57

Do you have your Netgear firewall appliance perform NAT & DHCP services for your local network? If so, is the Time Capsule (TC) reconfigured as a bridge? Also does the TC have a static local IP address? Finally, did you establish any QoS priorities on the port that the TC is connected to?

... and you mentioned "triple NAT." Is your modem a simple modem or a combination modem & router or gateway device? Regardless, what is its make & model?

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Answer 4

robx57 Author

Level 1

9 points

Mar 31, 2016 2:27 PM in response to Tesserax

Netgear is performing Nat and DHCP to TC. TC is not in bridge mode as I really wanted it to pass out Dynamic ip's. It has double nat also. No issues with anything since I bought the TC a couple years ago and set this all up. The slow speed issue started before the netgear was bought and continues to this day. Before the netgear my config was Modem (att/motorola 2210) - TC. I did not establish Qos priorities on the netgear as there is nothing else using any ports.

As suspected my speeds are now back up to normal at this moment.

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Answer 5

Tesserax

Level 10

158,088 points

Mar 31, 2016 2:40 PM in response to robx57

Netgear is performing Nat and DHCP to TC. TC is not in bridge mode as I really wanted it to pass out Dynamic ip's. It has double nat also.

The TC does offer a DHCP Only mode. It is designed to pass out static IP addresses, but potentially can be used to pass out the addresses coming from the Netgear. Although I wouldn't recommend it in this situation. A Double NAT is very inefficient. You really should avoid this if you can ... but it's your networking goals, not mine, that need to be satisfied.

One simple test, is to temporarily reconfigure the TC as a bridge and let the Netgear pass out the IP addresses. Try this configuration for a few days to see if the issue returns.

Before the netgear my config was Modem (att/motorola 2210) - TC. I did not establish Qos priorities on the netgear as there is nothing else using any ports.

Ah, the infamous Motorola (aka Netopia) 2210. This caught my attention. This particular modem has been problematic for the Apple routers. Motorola's documentation states that this modem can be used with a router, but it tends to cause a "Double NAT" condition when using them together. Are you using a PPPoE connection with your ISP?

I'm betting that this modem is the culprit. If it is over 5 yrs old, I would suggest that you replace it with another that AT&T supports.

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Answer 6

robx57 Author

Level 1

9 points

Mar 31, 2016 3:01 PM in response to Tesserax

No PPOE. Uverse. Same but different, I am sure you know what i mean. Proprietary modem, only other available is a router and they are having issues with those also. I changed that first it's only about two months old. And "yes" they are not the best modems out there. That is why I have a couple new ones on hand at all times. Thing that gets me is if I move lan connection from TC to modem while this is happening the speed come back to normal as expected 18m.Then when I plug it back into TC the speed drops off again. This speed issue only seems to happens for a couple hours each day. Now, I cannot say it happens everyday because I am not on the computer everyday nor am I at home like today. But I have been battling this for a while now and it is getting frustrating.

When you say "double nat is inefficient" what do you mean? I am looking for security and speed in my network, what else do you recommend? Maybe I am misunderstanding something????? My TC is set to DHCP only. Yes 2210 does nat, maybe I have to many? I cannot reconfigure 2210 not to nat, as it is what it is. Not much there to configure in the uverse world.

I would be willing to try a change as long as security and speed are not compromised. Suggestions?

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Answer 7

Tesserax

Level 10

158,088 points

Mar 31, 2016 3:54 PM in response to robx57

When you say "double nat is inefficient" what do you mean?

Basically, I am saying that all traffic coming or going to the TC must traverse through two NAT "firewalls." It really does not add much additional protection vs. the overall data transfer rate (throughput) loss across two WAN-LAN interfaces. As far as throughput think of NAT as a resistor in a circuit.

I am looking for security and speed in my network, what else do you recommend? Maybe I am misunderstanding something?????

Security and speed. Ah, now that is the conundrum ... you can't have both. The two "best" options for security are: 1) A full-featured firewall, and 2) Wireless security with a strong password. The firewall on your Netgear is far superior to that offered on any of the Apple base stations ... and you already have that covered. So, you are not really adding any additional "security" by using NAT on the AirPort, only adding another bottleneck for traffic to pass through.

My TC is set to DHCP only.

Ok, the TC has three basic router modes:

DHCP and NAT - This is the base station's default setting. It is performing as router as both services are enabled.
DHCP Only - NAT is disabled. The base station is acting as a DHCP server. Again this was designed to distribute static public IP addresses to local network clients. It wasn't meant to be used as a second DHCP server. (Note: If you have your TC configured as such AND are still getting a "Double NAT" message, then your Motorola 2210 is performing routing functions ... at least the NAT part.
Off (Bridge Mode) - Both DHCP & NAT are disabled. This would be the ideal configuration for your network.

Yes 2210 does nat, maybe I have to many? I cannot reconfigure 2210 not to nat, as it is what it is.

Hmm, I was led to believe that the 2210 can be reconfigured as a bridge. Maybe, I got misleading info on this modem. I know that there are a number of similar, but different versions of this modem. Unless you can get this reconfigured as a bridge, you are always going to have at least two of your devices with NAT enabled. FWIW, here is one link on how to reconfigure this modem as a bridge. It's dated (2008) as is the modem.

Ideally, what I was hoping for is the following:

Motorola (bridge mode) > Netgear (router) > TC (bridge mode)
In this configuration only the Netgear has NAT enabled.

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Answer 8

robx57 Author

Level 1

9 points

Mar 31, 2016 3:54 PM in response to Tesserax

Thank you for your replies and help. 🙂 I will digest all this information and make some changes. The PPOE 2210's "yes" you can put in bridge mode. They are the same as the netgear 3360 (updated) modems with a little different packaging. But as far as the uverse world is concerned the att routers (on the other side) will not authenticate unless it is talking to a (proprietary) att modem or router. So hence no bridge mode capabilities. Thats is the way I understand it.

Thank you again I will update at later date.

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