Ddns works fine but system (dnsmasq?) uses some old IPs

Hello,

I put my fritzbox 7360 a little bit away, it only works as a VDSL modem now.
I took my TP-LINK AC1750 (archer C7), put LEDE Reboot 17.01.4 r3560-79f57e422d / LuCI lede-17.01 branch (git-17.290.79498-d3f0685) (is this correct actual version?).
It has 4 ports LAN, 2 WLAN and a WAN connector. The fritzbox is connected as a VDSL modem to, the WAN and LEDE does pppoe.

The whole setup works fine for all LAN clients and WLAN clients, perfect.

However, system uses weird IP for a ddns address:

my ddns for zappa.mig19.de works fine:

090837       : Detect registered/public IP
 090837       : #> /usr/bin/nslookup zappa.mig19.de  >/var/run/ddns/myddns_ipv4.dat 2>/var/run/ddns/myddns_ipv4.err
 090837       : Registered IP '89.183.89.128' detected
 090837  WARN : Updating IP at DDNS provider failed - starting retry 2/0
 090837       : Detect local IP on 'network'
 090837       : Local IP '89.183.130.87' detected on network 'wan'
 090837       : Update needed - L: '89.183.130.87' <> R: '89.183.89.128'
 090837       : #> /bin/uclient-fetch -q -O /var/run/ddns/myddns_ipv4.dat -Y off 'https://CUSTOM_SECRET_URL' 2>/var/run/ddns/myddns_ipv4.err
 090838       : DDNS Provider answered:
ok
 090838  info : Update successful - IP '89.183.130.87' send
 090838  info : Forced update successful - IP: '89.183.130.87' send
 090838       : Waiting 600 seconds (Check Interval)

The new IP is used and updated everywhere on the internet, currently for example ping.eu correctly says the following:

--- PING zappa.mig19.de (89.183.130.87) 56(84) bytes of data. ---
64 bytes from 89.183.130.87: icmp_seq=1 ttl=58 time=20.4 ms
64 bytes from 89.183.130.87: icmp_seq=2 ttl=58 time=20.3 ms
64 bytes from 89.183.130.87: icmp_seq=3 ttl=58 time=20.3 ms
64 bytes from 89.183.130.87: icmp_seq=4 ttl=58 time=20.5 ms

Double check ifconfig, if 89.183.130.87 is correct:

pppoe-wan Link encap:Point-to-Point Protocol
          inet addr:89.183.130.87  P-t-P:81.14.248.241  Mask:255.255.255.255
[...]

...yes.

Bot local system uses some weird old address:

root@archer-c7:~# ping zappa.mig19.de
PING zappa.mig19.de (89.183.89.128): 56 data bytes
64 bytes from 89.183.89.128: seq=0 ttl=63 time=33.186 ms

If I stop dnsmasq system uses actual correct address but connected clients have no DNS anymore at all.

I appreciate your help very much, is there something wrong with dnsmasq?

Kind Regards
Konsti

Okay, meanwhile I found out one part of a solution is to use the option dns_server in the ddns config part. When not the own dnsmasq is queried with the old IP but for example 8.8.8.8 (which has actual entry from successful previous run) the part "[...]Updating IP at DDNS provider failed[...] vanishes and it recognizes a previous successful run.

However, root cause is that dnsmasq is keeping an old entry for the dynamic host for ever. How do I update my own entry or make this automatically updated every couple of minutes or so? So actually the caching of dnsmasq is ultra aggressive.

In other words: DDNS runs fine now, system (dnsmasq) keeps old address which seems for ever.

Solution: server=/mig19.de/8.8.8.8 into /etc/dnsmasq.conf.
I do not know if there is a better kind of automatic solution.