Regular internet loss (Archer C7v5)

Installing and Using OpenWrt
1

Hi,

I've been trying out OpenWRT recently, and really appreciate all the features it grants, though I am suffering from an incredibly frustrating issue.

Every hour or so (it's a bit random, sometimes shorter, sometimes longer), I lose internet connection on all my devices for about 10 seconds, then it resumes like nothing happened.

I have tried many things to try resolve it:

  • Hardcoded DNS on client side
  • Changed DNS on luci
  • Disabled software offloaing
  • Downgraded to v22

The system logs show nothing when it occurs.

Nothing seems to resolve it. I don't think its a hardware issue as I don't have any problems on stock firmware.

Anyone suffering from same issue? / Any suggestions?

Thanks!

2

was it the same before you flashed it ?

no error in the openwrt logs, would indicate the problem's elsewhere.

what if you run a continuous ping from a client to the router, and another
one from the router to say 8.8.8.8 ?
it'd be interesting to see what happens during one of the outages.

1 Like
3

Hey!

No issues before flashing.

I’ve actually been conducting these tests to learn more, this is how I figured out it’s not a DNS issue as I can’t ping resolved domains either.

Regarding the gateway test, I can confirm the router is still accessible during these blackouts, only the internet is not.

4

What's your ISP doing on your lease.. ie how long is it?

5

Not sure how I’d check this exactly, but definitely over a day. Also IP same before/after this issue so don’t think it’s this. (I’m with Virgin Media UK btw)

Thanks for suggestion

6

Try logread -e udhcpc

7

Thank you,

Thu Oct 13 19:17:22 2022 daemon.notice netifd: wan (2547): udhcpc: started, v1.33.2
Thu Oct 13 19:17:22 2022 daemon.notice netifd: wan (2547): udhcpc: sending discover
Thu Oct 13 19:17:22 2022 daemon.notice netifd: wan (2547): udhcpc: sending select for xx
Thu Oct 13 19:17:22 2022 daemon.notice netifd: wan (2547): udhcpc: lease of xx obtained, lease time 476933

I have xx'd my public ip

8

What's up with the date? October??

1 Like
9

I have no idea, my local time appears correct

10

Log into your router and go to Systems and confirm the Time and Date are correct. Sync with browser if not.

1 Like
11

OK. To @Bill question.

You have a 132 1/2 hour lease. By design udhcpc should request a renewal at lease half-life (66 1/4 hours), and repeat the process if not acknowledged by the ISP again at the remaining half-life until the renewal request is honoured, or the timer runs out which can cause a momentary pause until the ISP obliges by renewing your lease.

The timestamps in the logread output should ideally indicate that your ISP is renewing the lease at the first half-life request. i.e my ISP provides a 4 hr lease and it’s renewed every 2 hrs.

12

Yes, this is what I've checked. Seems all synced up.

image
image980×552 18 KB

13

I see, thanks for the explanation.

Do you think my actual lease time may be shorter/ renew is not functioning and this is what's causing the issue?

Also, do you have any idea what could be causing the October timestamp?

14

Your router booted with a time stamp of the last configured /etc/config file stamped time and the udhcpc started before you ntp time server corrected the time.

A good clean reboot would clear up your log.

and if you issue this command from cli it will reset the lease from your ISP
kill -USR1 $(pidof udhcpc)
Then a good clean reboot would clear up your log and refresh the lease fully.

15

Thank you, I have killed the process and rebooted. My logs seem correct now.

Not sure if this will fix the issue but will report back.

16

Unfortunately, still happening, just happened.

I'm guessing it may be hardware, though not sure why no issues on stock.

I mainly wanted to make sure no one else was getting similar issues so I know I wouldn't get the same issue if I purchased new hardware.

Still open to suggestions but thanks for the help so far.

17

What happened? Time or internet pause?

Run the logread -e udhcpc

18

Internet pause. Logs seem good:

Tue Feb  7 16:06:08 2023 daemon.notice netifd: wan (2210): udhcpc: started, v1.33.2
Tue Feb  7 16:06:09 2023 daemon.notice netifd: wan (2210): udhcpc: sending discover
Tue Feb  7 16:06:09 2023 daemon.notice netifd: wan (2210): udhcpc: sending select for xx
Tue Feb  7 16:06:09 2023 daemon.notice netifd: wan (2210): udhcpc: lease of xx obtained, lease time 469505
19

When the lease renews, is it the same IP address?

20

Usually, yes, though I'd have to wait 130 hours to verify.