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bds85466

join:2012-11-17
Waconia, MN

1 edit

UPDATE:ZyXEL PK5001Z Modem dropping exactly every 15 minutes

I've posted the following in the CenturyLink forum as well, but I thought I would post here as well as I believe it to be a potential router issue.

So I recently signed up for CL 10Mb DSL. For the most part it works great. Unless it comes to streaming or playing games online. Every 15 minutes on the nose the connection drops just momentarily. Long enough to stop streaming or kick me off a server.

I've watched the system log while streaming things, and like clockwork every 15-16 minutes, the internet cuts out no matter what, dropping my streaming connection. This is insanity for trying to play a game online.

Below is a snippet from the system log, showing the 15 minute routine (which logs 4 distinct activities during the drop). Check the time stamps:

11/17/2012 07:00:20 PM DHCP DHCP send discover packet
11/17/2012 07:00:20 PM DHCP DHCP receive offer packet
11/17/2012 07:00:20 PM DHCP DHCP send request packet
11/17/2012 07:00:21 PM DHCP DHCP receive ACK option
11/17/2012 07:15:58 PM DHCP DHCP send discover packet
11/17/2012 07:15:58 PM DHCP DHCP receive offer packet
11/17/2012 07:15:58 PM DHCP DHCP send request packet
11/17/2012 07:16:00 PM DHCP DHCP receive ACK option
11/17/2012 07:31:35 PM DHCP DHCP send discover packet
11/17/2012 07:31:36 PM DHCP DHCP receive offer packet
11/17/2012 07:31:36 PM DHCP DHCP send request packet
11/17/2012 07:31:37 PM DHCP DHCP receive ACK option
11/17/2012 07:49:12 PM DHCP DHCP send discover packet
11/17/2012 07:49:13 PM DHCP DHCP receive offer packet
11/17/2012 07:49:13 PM DHCP DHCP send request packet
11/17/2012 07:49:14 PM DHCP DHCP receive ACK option
11/17/2012 08:00:12 PM DHCP DHCP send discover packet
11/17/2012 08:00:13 PM DHCP DHCP receive offer packet
11/17/2012 08:00:13 PM DHCP DHCP send request packet
11/17/2012 08:00:14 PM DHCP DHCP receive ACK option
11/17/2012 08:15:49 PM DHCP DHCP send discover packet
11/17/2012 08:15:50 PM DHCP DHCP receive offer packet
11/17/2012 08:15:50 PM DHCP DHCP send request packet
11/17/2012 08:15:51 PM DHCP DHCP receive ACK option
11/17/2012 08:31:26 PM DHCP DHCP send discover packet
11/17/2012 08:31:26 PM DHCP DHCP receive offer packet
11/17/2012 08:31:26 PM DHCP DHCP send request packet
11/17/2012 08:31:26 PM DHCP DHCP receive ACK option
11/17/2012 08:46:59 PM DHCP DHCP send discover packet
11/17/2012 08:46:59 PM DHCP DHCP receive offer packet
11/17/2012 08:46:59 PM DHCP DHCP send request packet
11/17/2012 08:47:00 PM DHCP DHCP receive ACK option
11/17/2012 09:04:36 PM DHCP DHCP send discover packet
11/17/2012 09:04:36 PM DHCP DHCP receive offer packet
11/17/2012 09:04:36 PM DHCP DHCP send request packet
11/17/2012 09:04:37 PM DHCP DHCP receive ACK option

You get the picture....

The condition is unnoticeable if you are simply browsing the internet because it quickly connects again. Doesn't matter if the connection is wired or wireless.

I've read that there are others having/have had this problem before.

Is the only solution to this a new router? Is there something in the settings that can be changed? Is there something on Century Link's end? The above log was created with the DSL router plugged directly in to the NID test jack outside so there's not a lot more I can do on my end for the physical lines.

Thanks.

JPedroT

join:2005-02-18
kudos:1

Re: ZyXEL PK5001Z Modem dropping exactly every 15 minutes

The log does not say anything more about lower level of things.
But what you see is that the device requests a new IP after 15 minutes as you say.

Now the question is why does this happen, there can be a lot of reasons.

But one thing I have seen before, is that the intial dhcp request is by broadcast and then when it wants to renew it does it with a another broadcast. The DHCP expects it to be a unicast, so its a mismatch. This is just a guess, but without some more details its hard to do any proper guess work

Can you get a packet trace that we can look at?
--
"Perl is executable line noise, Python is executable pseudo-code."

bds85466

join:2012-11-17
Waconia, MN
Yeah, sure thing if you can walk me through the steps. I'm not sure what that is .

Another thing I noticed is that the IPv4 timer counts up to 15 minutes and then resets, triggering the above drop condition.


Brano
I hate Vogons
Premium,MVM
join:2002-06-25
Burlington, ON
kudos:11
What IPv4 timer? Can you provide screenshot?

bds85466

join:2012-11-17
Waconia, MN
I can't at the moment as I'm away from home. Can do after I get home though.

It's the uptime timer shown with all of the IPv4 stats.

If you are familiar with the firmware menus, I believe it is under the Modem Status heading, and then the Internet Status side menu; though that's completely by memory.

It basically refreshes every 10 seconds or so, and it counts up (but never makes it past 15 minutes without resetting back down to zero). Right at that time is when the connection drops.

bds85466

join:2012-11-17
Waconia, MN
reply to Brano
sorry, i did a qreply instead....

bds85466

join:2012-11-17
Waconia, MN
Another thing, when a diagnostics test is run, the "encapsulation test" fails every time.

bds85466

join:2012-11-17
Waconia, MN
reply to JPedroT
said by JPedroT:

Can you get a packet trace that we can look at?

Anyone know how to go about doing this? Sorry, new to this...


Brano
I hate Vogons
Premium,MVM
join:2002-06-25
Burlington, ON
kudos:11
Reviews:
·TekSavvy DSL
·Bell Fibe
Do you have to connection 'Nailed-up"? If not, make it so.

Do you have latest firmware on the unit? According to this page »qwest.centurylink.com/internethe···are.html the latest is "QZP002-3.4.012.0"

Are you using the PK5001Z as modem only? Do you have another router in your setup?
Or is the PK5001Z being used as modem/router?

As for the packet capture, there are basically several ways to do it
1) If the device itself supports a packet capture the use that.
2) If you have a managed switch or true HUB, place it between the modem and router and use the sniffing port capability to capture the packets (assuming you have separate router and modem and access to managed switch or true HUB).

bds85466

join:2012-11-17
Waconia, MN
Brano,

Thanks for the response. I don't know if I have the connection "nailed up". I'm guessing there's some way to check in the firmware.

When I tried to upgrade my firmware via the CL site yesterday it said I had the most up to date release -- though I will double check on the exact version.

No additional router connected at this time, just the modem. I'll look around in the firmware and see (for both the packet capture and the nail up).

bds85466

join:2012-11-17
Waconia, MN
reply to Brano
Click for full size
prior to drop
Click for full size
at drop
said by Brano:

What IPv4 timer? Can you provide screenshot?



Brano
I hate Vogons
Premium,MVM
join:2002-06-25
Burlington, ON
kudos:11
Is this a PPPoE connection?

bds85466

join:2012-11-17
Waconia, MN
reply to bds85466
Click for full size
tracer route to yahoo.com
DSL Status

Connection
Status
DSL Downstream:
9.434 Mbps
DSL Upstream:
0.894 Mbps
DSL Link Statistics

Link Statistic
Status
Broadband Mode Setting:
MULTIMODE
Broadband Mode Detected:
ADSL_2plus
DSL Link Uptime:
13H:38M:34S
Retrains:
11
Retrains in Last 24 Hours:
0
Loss of Power Link Failures:
0
Loss of Signal Link Failure:
0
Link Train Errors:
6
Unavailable Seconds:
2406
Transport Mode:
ADSL
Path Parameter:
8/35
Priority:
UBR without PCR
Service Type:
LLC Bridged
DSL Power

Levels
Downstream
Upstream
SNR
8.9 dB
10.0 dB
Attenuation
40.2 dB
26.0 dB
Power
20.1 dBm
12.4 dBm
DSL Transport

Transport
Downstream
Upstream
Packets:
702841
531844
Error Packets:
28367
0
24 Hour Usage:
12.289 MB
0.000 MB
Total Usage:
1018.137 MB
0.000 MB
DSL Channel

Levels
Near End
Far End
Channel Type:
Fast
Fast
CRC Errors:
28367
883
15 Minute CRC:
3
0
RS FEC:
0
0
15 Minute FEC:
0
0

bds85466

join:2012-11-17
Waconia, MN
reply to Brano
said by Brano:

Is this a PPPoE connection?

Are you asking if it's an ethernet connection to the router? Yes.

Forgive me I'm not fluent in networking.

Still haven't found lingo to Nail the connection in the firmware....on to another day...gotta get to bed.

Thanks for your help!

JPedroT

join:2005-02-18
kudos:1
reply to bds85466
Packet trace must be an option on your device, if not then its not possible since you got a DSL device from the look of it

I am not familiar with your device, but from the stats you have posted it seems your link is a either long or noisy.

There are a bunch of CRC errors, and your link has been retrained 11 times during the last 13 hours. Which can indicate that its noisy, or its just impuls noise.

Cant help you much more, since I am not familiar with the product nor the ISP.
--
"Perl is executable line noise, Python is executable pseudo-code."

OGalati

join:2005-08-19
Argentina
Hi.

There is a line stating
Retrains in Last 24 Hours: 0
so Retrains: 11 could be from power up.
I think it itsn't a DSL link issue, but a PPP one.
If you can't find the Nailed Up setting, check for PPP Session Duration parameter or so.

Regards.


Brano
I hate Vogons
Premium,MVM
join:2002-06-25
Burlington, ON
kudos:11
Reviews:
·TekSavvy DSL
·Bell Fibe
reply to bds85466
Check Advanced -> WAN settings and post screenshot please.
Going by this »qwest.centurylink.com/internethe···ock.html you should have PPPAutoConnect enabled.

bds85466

join:2012-11-17
Waconia, MN
reply to OGalati
said by OGalati:

I think it itsn't a DSL link issue, but a PPP one.

I would agree (as best I can tell) that there is no dropping of the dsl signal. The 'internet' connectivity is what appears to be dropping.

The question is, can this condition be identified/corrected somehow in the firmware settings of the router or must I simply demand a new model from centurylink. Their tech support to this point have been, well...unfamiliar.


dnoyeB
Ferrous Phallus

join:2000-10-09
Southfield, MI
kudos:1
Reviews:
·Comcast

1 edit
reply to bds85466
Im not sure if the Zyxel considers the link lost when the hardware is disconnected of when the IP is gone. If its when the IP is gone, then that explains why the timer is resetting. My guess is that its based on IP. Otherwise it wouldn't be called "IPv4" uptime.

DHCP addresses have an expiration time. Perhaps the DHCP server is giving your device an expiration time of 15 minutes. Maybe you can check with wireshark or something. Based on the log it does not look like its loosing the IP address. Its just renewing it.

Try manually assigning the same IP address to your WAN and see if that stops the cycling. If so, you need to get the DHCP server to quit giving such a small expiration time.

Sorry, I guess that answer is a bit off since you are not using a router but a modem. Still, it looks like the modem is being given a small DHCP lease time. I don't know if that lease time is coming from your ISP, or part of your modem. For me and my cable modem, it comes from the ISP's configuration of my cable modem.

--
dnoyeB

"Then said I, Wisdom [is] better than strength: nevertheless the poor
man's wisdom [is] despised, and his words are not heard. " Ecclesiastes
9:16

bds85466

join:2012-11-17
Waconia, MN
reply to Brano
said by Brano:

Check Advanced -> WAN settings and post screenshot please.
Going by this »qwest.centurylink.com/internethe···ock.html you should have PPPAutoConnect enabled.

I'll do this when I get home and post it.

bds85466

join:2012-11-17
Waconia, MN

2 edits
reply to dnoyeB
said by dnoyeB:

Sorry, I guess that answer is a bit off since you are not using a router but a modem. Still, it looks like the modem is being given a small DHCP lease time. I don't know if that lease time is coming from your ISP, or part of your modem. For me and my cable modem, it comes from the ISP's configuration of my cable modem.

Well to be fair (and to your credit) it is a modem that routes as well....

That was what I was starting to question as well, is this a pre-installed routine to keep uptime to a minimum while idle?...I'm clueless.

Bear with me because I'm completely ignorant when it comes to networking and all the acronyms are starting to blow my mind. Simply a residential customer trying to watch netflix...

So D standing for dynamic, basically DHCP is a way to eliminate the need for static IP's and entering them in? Is my modem 'asking' to join the network (and obtaining a new IP every time)?

Let me see if I can grasp the DHCP handshake correctly:

1. So my modem sends out protocol and asks the DHCP server if it can join the network.

2. The DHCP server then creates potential IP's and other info for the modem (MAC address, LEASE DURATION, etc) sends the info back to the modem.

3. The modem sends acceptance information for one of the IP's and the other info in the packet.

4. The DHCP server sends the actual packet of information to the modem, completing the IP configuration -- using the negotiated parameters including IP and duration.

...if this is correct, I'd say that in most cases, the DHCP server is what dictates the length of the lease, however, it may not be what is causing the problem. The server could be sending out a more lengthy duration, but we might not ever know what the duration is?

The modem still could be acting funky, sending out the "DISCOVER" protocol packet for some odd reason every 15 minutes.

As you point out:

said by dnoyeB:

Based on the log it does not look like its loosing the IP address. Its just renewing it.

said by dnoyeB:

Try manually assigning the same IP address to your WAN and see if that stops the cycling. If so, you need to get the DHCP server to quit giving such a small expiration time.

Though I've never done it before, maybe I will try setting up a static IP for the modem as you suggest? Where would I find that IP to use?

bds85466

join:2012-11-17
Waconia, MN
reply to bds85466

UPDATE: ZyXEL PK5001Z Modem dropping exactly every 15 minutes

So I was out to lunch today and when I got back from lunch I had a message from a Century Link Rep. He was from the "Escalations Team".

He went on to explain that the symptoms that I described (IPv4 cutting out every 15 minutes, dropping the connection) specifically pointed to a known issue with the PK5001 series.

He then went on to say that he was shipping out a new Westell 7500 modem to me overnight, with the shipping waived.

Sounds good to me!

So we'll see how that one works and I'll keep everyone posted.


dnoyeB
Ferrous Phallus

join:2000-10-09
Southfield, MI
kudos:1
Reviews:
·Comcast
reply to bds85466

Re: UPDATE:ZyXEL PK5001Z Modem dropping exactly every 15 minutes

Your dhcp sequence is basically correct. However, MAC address is a fixed address of your network interface. It does not change ever. So when your unit does a broadcast, it uses its MAC address. DHCP server sends the reply to that MAC address. The ACK step I don't think has any data in it. Just an acknowledgement from the server to the client. The 'offer' should have all the good stuff in it.

Glad to hear your on the way to success!
--
dnoyeB
"Then said I, Wisdom [is] better than strength: nevertheless the poor man's wisdom [is] despised, and his words are not heard. " Ecclesiastes 9:16

OGalati

join:2005-08-19
Argentina

1 recommendation

Guys, under PPP there isn't DHCP involved at all (opposite to cablemodem). IP assignation is managed by IPCP protocol and PPP link itself is controlled by LCP protocol.

Regards


Brano
I hate Vogons
Premium,MVM
join:2002-06-25
Burlington, ON
kudos:11
Reviews:
·TekSavvy DSL
·Bell Fibe
said by OGalati:

Guys, under PPP there isn't DHCP involved at all (opposite to cablemodem). IP assignation is managed by IPCP protocol and PPP link itself is controlled by LCP protocol.

Agreed, but why the DHCP logs? ...that must be part of the bug/issue.

OGalati

join:2005-08-19
Argentina
said by Brano:

Agreed, but why the DHCP logs? ...that must be part of the bug/issue.

Yeah, it's strange for me too, mainly considering it's working


nschwen

@embarqhsd.net
reply to bds85466

Re: ZyXEL PK5001Z Modem dropping exactly every 15 minutes

I was having this very same issue, and read this thread with great interest. Also I was having trouble with some devices connecting via WiFi (would connect one day, but be unable the next, even in the same room as the router). This and other issues has convinced me the router firmware is basically just bad. Not horrible, but quite buggy.

I was able to get a stable connection by turning off the WiFi and putting the device into 'Bridge' mode (found under Advanced->WAN settings). This basically turns it into a simple modem, no router capabilities at all. This mean however you need a different device to handle router functions. I had a CradlePoint MBR 95 from my days of using wireless modems (very solid performer). Worked without any configuration. Just ran a network cable from one of the network ports on the Zyxel to the WAN port on the CradlePoint, and poof, internet. It's been stable for the last 24 hours, zero connection drops while gaming or using work VPN (both were a real pain with the drops every 15 mins).

Once you set the Zyxel into Bridge mode, you can't connect to it's GUI pages any longer; it's just a dumb modem now. To get it back to 'normal', you have to do a hard reset using the pinhole button on the back. Both bridging and resetting are detailed on Zyxel's website (via videos hosted on YouTube).

If Zyxel comes out with a firmware update I may give it another try, because I did like some of the monitoring features they offer. But until I feel like rolling the dice again, this setup is working great so far!

oldfartz

join:2012-12-29
Estes Park, CO
reply to bds85466

Re: UPDATE:ZyXEL PK5001Z Modem dropping exactly every 15 minutes

Has there been a resolution on this issue? Sounds like you have a dynamic IP address and your ISP's server has you setup with a 15minute "time to live or TTL". It will release and refresh every 15 minutes. Frequently giving you the same IP, but has reset the timer. I expect one way to solve this is to buy a static IP from CL. No more TTL.