Privet DNS server with bridge mode

Installing and Using OpenWrt Network and Wireless Configuration
1

Hi there
I have some ap work with openwrt 18 for public area and these bridge ap get connection from data center in this data center I install bind DNS server with IP 172.109.25.3/24 nas1
172.109.25.4/24 nas 2 backups nas2
And I get main router with IP 172.0.1.1/20
I routing 172.109.25.0/24 to 172.0.0.0/20
It's ok the DNS work perfectly with any router like tplinik else but when I use openwrt with AP mode I get error with DNS in my client mobile why I get this error and any idea how I fix it . * The same problem if I enable dnsmasq
Thx

2

It sounds like you haven't properly configured your DHCP server to provide the "private" DNS server in its response.

Another possibility is that an older lease with different DNS is still being used by the client(s).

2 Likes
3

Thank u I config my DHCP to use the DNS in my main mikrotik router and it's ok
Is there any other suggestion it's not one client device there's over 20 client with this issue

4

How long was the lease time with the previous DHCP server? (Some are configured for days, not minutes.) Are you seeing the clients renewing/obtaining leases from the new DHCP server?

Unfortunately, a DHCP server can't "force" a client to drop a valid lease. If that is the core of the problem, then time will hopefully resolve it. Without centralized management of the clients (such as some enterprises use with their Windows clients), there isn't much more that I know that you could do.

1 Like
5

mikrotik
this image from my mikrotik dhcp leases

mikrotik%202

this image frome my dhcp network config i wish help as to know what is problem


config interface 'loopback'
        option ifname 'lo'
        option proto 'static'
        option ipaddr '127.0.0.1'
        option netmask '255.0.0.0'

config globals 'globals'
        option ula_prefix 'fdba:027d:8a7d::/48'

config interface 'lan'
        option type 'bridge'
        option ifname 'eth0'
        option proto 'static'
        option ipaddr '172.0.15.2'
        option netmask '255.255.240.0'
        option gateway '172.0.1.1'
        option dns '172.109.25.3'

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this my network ap config

config dnsmasq
        option domainneeded '1'
        option boguspriv '1'
        option filterwin2k '0'
        option localise_queries '1'
        option rebind_protection '1'
        option rebind_localhost '1'
        option local '/lan/'
        option domain 'lan'
        option expandhosts '1'
        option nonegcache '0'
        option authoritative '1'
        option readethers '1'
        option leasefile '/tmp/dhcp.leases'
        option resolvfile '/tmp/resolv.conf.auto'
        option nonwildcard '1'
        option localservice '1'
        option ignore '1'
config dhcp 'lan'
        option interface 'lan'
        option start '100'
        option limit '150'
        option leasetime '12h'
        option dhcpv6 'server'
        option ra 'server'
        option ignore '1'
config dhcp 'wan'
        option interface 'wan'
        option ignore '1'

this my dhcp config

6

i think the dhcp work fine but i think bad configuration in my openwrt AP what u think

7

Any suggestion with this problem