Posted: Thu Feb 20, 2020 1:19 Post subject: Router wouldn't give my computer a IP, odd logs
Firmware: DD-WRT v3.0-r42335 mini (02/10/20)
Not sure what happened here but I changed my MAC to get a new address from my ISP.
I was getting spammed by 220.127.116.11 to port 48712 and decided to get a new IP, then all this happened:
Feb 19 15:23:16 Router daemon.warn dnsmasq: no servers found in /tmp/resolv.dnsmasq, will retry
Feb 19 15:23:16 Router daemon.info dnsmasq: read /etc/hosts - 3 addresses
Feb 19 15:23:17 Router user.info : sfe : shortcut forwarding engine successfully started
Feb 19 15:24:19 Router kern.err kernel: INFO: rcu_sched detected stalls on CPUs/tasks:
Feb 19 15:24:19 Router kern.err kernel: 1-...: (0 ticks this GP) idle=d39/140000000000000/0 softirq=2511907/2511907 fqs=5999
Feb 19 15:24:19 Router kern.err kernel: (detected by 0, t=6002 jiffies, g=161057, c=161056, q=2701)
Feb 19 15:24:19 Router kern.info kernel: Task dump for CPU 1:
Feb 19 15:24:19 Router kern.info kernel: radio_timer R running 0 1116 1 0x00000002
Feb 19 15:24:19 Router kern.warn kernel: Backtrace:
Feb 19 15:24:19 Router kern.warn kernel: Function entered at [<800765e0>] from [<80076698>]
Feb 19 15:24:19 Router kern.warn kernel: r5:ffffe000 r4:86635f30
Feb 19 15:24:19 Router kern.warn kernel: Function entered at [<86635efc>] from [<86635f14>]
Feb 19 15:24:19 Router kern.warn kernel: Function entered at [<86635f24>] from [<86635f4c>]
Feb 19 15:24:19 Router kern.warn kernel: Backtrace aborted due to bad frame pointer <86635f60>
I wonder if this is at all related to the DHCP issue i've found in builds newer than the 12/10/2019 build on the WRT1200AC.
With any newer build my router will not give DHCP leases to clients. I suspect an issue with dnsmasq. I've narrowed down the issue enough that if I click the apply button on the services tab at the moment a client is trying to get a lease it will give out a lease when dnsmasq is restarted then it stops responding again.
My router has a somewhat complex configuration, so I have been unable to dedicate the time to restoring to factory defaults and then reconfiguring, and retesting dhcp after each config change. To find what is breaking it. Nor do I 100% trust the backup and restore config function to safely restore my router's config, since this has left me with a mangled config long ago in the past.
Whenever I get around to dedicating the time to find what is wrong. I'll probably just leave my current router as is and grab one of my other WRT1200AC that are just being used as additional APs in my home to factory reset and test each config change.
Joined: 08 May 2018 Posts: 3490 Location: Texas, USA
Posted: Thu Feb 20, 2020 22:49 Post subject:
Probably related to some upstream patches in dnsmasq that are not applied. AFAIK, DD is still running v2.80 stable. I wish I knew when a new RC or version was going to drop. _________________ E4200 v1 DD-WRT 42460 mega (02/20/20) K3.x
R7000P DD-WRT 40270M kongac
E4200 v1 FreshTomato 2020.1
E4200 v1 FreshTomato 2020.2.development
R7000 FreshTomato 2020.2.development
E4200 v1 1.0.07.development
WRT3200ACM OpenWRT 18.06.7
Linux User #377467 counter.li.org / linuxcounter.net