Problem Statement www.youtube.com ).
OpenWRT Version: Powered by LuCI openwrt-22.03 branch (git-22.245.77528-487e58a) / OpenWrt 22.03.0 r19685-512e76967f
Trouble shoot youtube.com and it will automatically resolve the hostname.
C:\>ping youtube.com
Pinging youtube.com [142.250.191.46] with 32 bytes of data:
Reply from 142.250.191.46: bytes=32 time=11ms TTL=116
Reply from 142.250.191.46: bytes=32 time=12ms TTL=116
Reply from 142.250.191.46: bytes=32 time=12ms TTL=116
Reply from 142.250.191.46: bytes=32 time=14ms TTL=116
Ping statistics for 142.250.191.46:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 11ms, Maximum = 14ms, Average = 12ms
C:\>nslookup youtube.com
Server: dns.google
Address: 8.8.8.8
Non-authoritative answer:
Name: youtube.com
Addresses: 2607:f8b0:4005:80e::200e
142.251.214.142
Troubleshooting in OpenWRT, nslookup results in server refused.
root@GenericRouter:~# ping 142.250.192.46
PING 142.250.192.46 (142.250.192.46): 56 data bytes
64 bytes from 142.250.192.46: seq=0 ttl=58 time=237.418 ms
64 bytes from 142.250.192.46: seq=1 ttl=58 time=238.128 ms
64 bytes from 142.250.192.46: seq=2 ttl=58 time=236.965 ms
64 bytes from 142.250.192.46: seq=3 ttl=58 time=237.119 ms
64 bytes from 142.250.192.46: seq=4 ttl=58 time=238.349 ms
^C
--- 142.250.192.46 ping statistics ---
5 packets transmitted, 5 packets received, 0% packet loss
round-trip min/avg/max = 236.965/237.595/238.349 ms
root@GenericRouter:~# ping youtube.com
ping: bad address 'youtube.com'
root@GenericRouter:~# nslookup youtube.com
Server: 127.0.0.1
Address: 127.0.0.1:53
** server can't find youtube.com: REFUSED
** server can't find youtube.com: REFUSED
Comments
root@GenericRouter:~# cat /etc/resolv.conf
search lan
nameserver 127.0.0.1
nameserver ::1
Comment https://openwrt.org/docs/guide-user/base-system/dhcp_configuration#logging_dns_queries
uci set dhcp.@dnsmasq[0].logqueries="1"
uci commit dhcp
/etc/init.d/dnsmasq restart
udhcpc: started, v1.35.0
udhcpc: broadcasting discover
udhcpc: no lease, failing
sh: write error: No space left on device
Could the DNS problem related to no space left? But that doesn't make sense.
root@GenericRouter:~# free
total used free shared buff/cache available
Mem: 122328 45168 37972 8048 39188 28972
Swap: 422284 55352 366932
root@GenericRouter:~# df -h
Filesystem Size Used Available Use% Mounted on
/dev/root 4.0M 4.0M 0 100% /rom
tmpfs 59.7M 59.7M 0 100% /tmp
/dev/mtdblock9 8.9M 7.0M 1.9M 78% /overlay
overlayfs:/overlay 8.9M 7.0M 1.9M 78% /
tmpfs 512.0K 0 512.0K 0% /dev
/dev/sda1 56.0G 992.0K 53.1G 0% /mnt/sda1
root@GenericRouter:~# uci show fstab; block info
fstab.@global[0]=global
fstab.@global[0].anon_swap='0'
fstab.@global[0].auto_swap='1'
fstab.@global[0].auto_mount='1'
fstab.@global[0].delay_root='5'
fstab.@global[0].check_fs='0'
fstab.@global[0].anon_mount='1'
fstab.@mount[0]=mount
fstab.@mount[0].target='/mnt/sda1'
fstab.@mount[0].uuid='c2594417-e1ef-4d38-985d-9a7583666e39'
fstab.@mount[0].enabled='1'
fstab.@swap[0]=swap
fstab.@swap[0].device='/dev/sda2'
fstab.@swap[0].enabled='1'
/dev/mtdblock8: UUID="246e008f-cce5fe3e-a4b92bef-be0c6219" VERSION="4.0" MOUNT="/rom" TYPE="squashfs"
/dev/mtdblock9: MOUNT="/overlay" TYPE="jffs2"
/dev/sda1: UUID="c2594417-e1ef-4d38-985d-9a7583666e39" VERSION="1.0" MOUNT="/mnt/sda1" TYPE="ext4"
/dev/sda2: UUID="ae3c1777-7a70-4fd0-a14d-0aefef420711" LABEL="SWAP" VERSION="1" TYPE="swap"
root@GenericRouter:~#
powtrix
December 12, 2022, 2:00am
5
No left space ..
Define log to external disk and restart the router:
mkdir -pv /mnt/sda1/logs
uci set system.@system[0].log_proto='udp'
uci set system.@system[0].conloglevel='8'
uci set system.@system[0].cronloglevel='5'
uci set system.@system[0].log_file='/mnt/sda1/logs/system.log'
uci commit
reboot
powtrix
December 12, 2022, 2:05am
6
You should use this disk as root:
1 Like
I already configured log files to be saved on /mnt/sda1
But regardless, I did a reboot and it started to work ok
root@GenericRouter:~# cat /etc/resolv.conf
search lan
nameserver 127.0.0.1
nameserver ::1
root@GenericRouter:~# nslookup youtube.com
Server: 127.0.0.1
Address: 127.0.0.1:53
Non-authoritative answer:
Name: youtube.com
Address: 142.250.189.238
Non-authoritative answer:
Name: youtube.com
Address: 2607:f8b0:4005:812::200e
root@GenericRouter:~# free
total used free shared buff/cache available
Mem: 122328 35652 68356 232 18320 52832
Swap: 422284 0 422284
root@GenericRouter:~# df -h
Filesystem Size Used Available Use% Mounted on
/dev/root 4.0M 4.0M 0 100% /rom
tmpfs 59.7M 232.0K 59.5M 0% /tmp
/dev/mtdblock9 8.9M 7.0M 1.9M 78% /overlay
overlayfs:/overlay 8.9M 7.0M 1.9M 78% /
tmpfs 512.0K 0 512.0K 0% /dev
/dev/sda1 56.0G 992.0K 53.1G 0% /mnt/sda1
root@GenericRouter:~# uci show dhcp.@dnsmasq[0]
dhcp.cfg01411c=dnsmasq
dhcp.cfg01411c.domainneeded='1'
dhcp.cfg01411c.localise_queries='1'
dhcp.cfg01411c.rebind_protection='1'
dhcp.cfg01411c.rebind_localhost='1'
dhcp.cfg01411c.local='/lan/'
dhcp.cfg01411c.domain='lan'
dhcp.cfg01411c.expandhosts='1'
dhcp.cfg01411c.authoritative='1'
dhcp.cfg01411c.readethers='1'
dhcp.cfg01411c.leasefile='/tmp/dhcp.leases'
dhcp.cfg01411c.localservice='1'
dhcp.cfg01411c.resolvfile='/tmp/resolv.conf.d/resolv.conf.auto'
dhcp.cfg01411c.sequential_ip='1'
dhcp.cfg01411c.dhcpleasemax='30'
After removing the manually configured DNS on windows PC, nslookup used the router's DNS server successfully,
C:\>nslookup youtube.com
Server: GenericRouter.lan
Address: 10.0.0.1
Non-authoritative answer:
Name: youtube.com
Addresses: 2607:f8b0:4005:80b::200e
142.250.188.14
And this time, there is no issue restarting dnsmasq
root@GenericRouter:~# uci set dhcp.@dnsmasq[0].logqueries="1"
root@GenericRouter:~# uci commit dhcp
root@GenericRouter:~# /etc/init.d/dnsmasq restart
udhcpc: started, v1.35.0
udhcpc: broadcasting discover
udhcpc: no lease, failing
root@GenericRouter:~#
Very strange.
ahh,
the tmpf was completely eaten up before the reboot.Before reboot
root@GenericRouter:~# df -h
Filesystem Size Used Available Use% Mounted on
/dev/root 4.0M 4.0M 0 100% /rom
tmpfs 59.7M 59.7M 0 100% /tmp
/dev/mtdblock9 8.9M 7.0M 1.9M 78% /overlay
overlayfs:/overlay 8.9M 7.0M 1.9M 78% /
tmpfs 512.0K 0 512.0K 0% /dev
/dev/sda1 56.0G 992.0K 53.1G 0% /mnt/sda1
After reboot
root@GenericRouter:~# df -h
Filesystem Size Used Available Use% Mounted on
/dev/root 4.0M 4.0M 0 100% /rom
tmpfs 59.7M 232.0K 59.5M 0% /tmp
/dev/mtdblock9 8.9M 7.0M 1.9M 78% /overlay
overlayfs:/overlay 8.9M 7.0M 1.9M 78% /
tmpfs 512.0K 0 512.0K 0% /dev
/dev/sda1 56.0G 992.0K 53.1G 0% /mnt/sda1
Let's see what is filling up the tmp folder
root@GenericRouter:~# df -h
Filesystem Size Used Available Use% Mounted on
/dev/root 4.0M 4.0M 0 100% /rom
tmpfs 59.7M 1.2M 58.6M 2% /tmp
/dev/mtdblock9 8.9M 7.0M 1.9M 78% /overlay
overlayfs:/overlay 8.9M 7.0M 1.9M 78% /
tmpfs 512.0K 0 512.0K 0% /dev
/dev/sda1 56.0G 992.0K 53.1G 0% /mnt/sda1
root@GenericRouter:~# du /tmp | sort -n
0 /tmp/.uci
0 /tmp/dnsmasq.d
0 /tmp/etc/uhttpd
0 /tmp/extroot
0 /tmp/lib
0 /tmp/lib/misc
0 /tmp/lock
0 /tmp/overlay
0 /tmp/run/collectd
0 /tmp/run/hostapd
0 /tmp/run/rpcd
0 /tmp/run/ubus
0 /tmp/run/wpa_supplicant
0 /tmp/shm
0 /tmp/spool
0 /tmp/spool/cron
0 /tmp/tmp
4 /tmp/hosts
4 /tmp/resolv.conf.d
4 /tmp/run/dnsmasq
8 /tmp/etc
8 /tmp/sysinfo
12 /tmp/state
40 /tmp/run
1088 /tmp/log
1180 /tmp
powtrix
December 12, 2022, 2:41am
9
consider using external disk as root, 1.9mb is eminent risk
1 Like
Turns out it was ulogd that's eating the ram
root@GenericRouter:/tmp# find /tmp -size +10k | xargs ls -lh
-rw-r--r-- 1 root root 4.4M Dec 11 19:30 /tmp/log/ulogd_syslogemu.log
-r--r--r-- 1 root root 57.0K Dec 11 18:56 /tmp/luci-modulecache/6C7563692E64697370617463686572
-r--r--r-- 1 root root 19.0K Dec 11 18:56 /tmp/luci-modulecache/6C7563692E68747470
-r--r--r-- 1 root root 24.9K Dec 11 18:56 /tmp/luci-modulecache/6C7563692E737973
system
December 22, 2022, 3:36am
11
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