hi every one, I have many branches, some branches use mikrotik + unifi and another uses draytek + unifi, on unifi I create 2 ssid: employee and guest. At branches using mikrotik + unifi, when customers connect to employee network, sometimes dns timeout error occurs. When customers connect to the guest, it works normally. branches using draytek work ok. There are a lot of friends of mine who have also reflected this error. Is it the fault of the unifi, mikrotik or my configuration.
It depends, but I’m sure you understand that by lack of any relevant information this question can’t be answered…
Can you please share your MikroTik configuration (/export hide-sensitive)?
Both employees and guests networks are using the same DNS server or different ones? I bet not, thus guests having no problems.
Are you using any king of QoS? Maybe double check it. Might cut off DNS.
Are you using any king of rate limiting or “ddos” protection? Try disabling.
ubitquiti
/interface bridge
add name=LAN
/interface ethernet
set [ find default-name=ether2 ] name=pppoe-out2
/interface pppoe-client
add disabled=no interface=ether1 name=pppoe-out1 password=h676443 user=
sgfdl-190627-443
/interface vlan
add interface=LAN name=vlan10 vlan-id=10
/interface list
add name=lan
add name=LAN_NB
/interface wireless security-profiles
set [ find default=yes ] supplicant-identity=MikroTik
/ip pool
add name=dhcp_pool0 ranges=192.168.10.2-192.168.10.254
add name=dhcp_pool1 ranges=172.16.0.2-172.16.0.254
/ip dhcp-server
add address-pool=dhcp_pool0 disabled=no interface=LAN lease-time=10h10m name=
dhcp1
add address-pool=dhcp_pool1 disabled=no interface=vlan10 lease-time=10h10m
name=dhcp2
/system logging action
set 1 disk-file-name=log
/user group
set full policy="local,telnet,ssh,ftp,reboot,read,write,policy,test,winbox,pas
sword,web,sniff,sensitive,api,romon,dude,tikapp"
/interface bridge port
add bridge=LAN interface=ether3
add bridge=LAN interface=ether4
add bridge=LAN interface=ether5
add bridge=LAN interface=ether6
add bridge=LAN interface=ether7
add bridge=LAN interface=ether8
add bridge=LAN interface=ether9
add bridge=LAN interface=ether10
/ip neighbor discovery-settings
set discover-interface-list=!dynamic
/interface list member
add interface=LAN list=LAN_NB
add interface=vlan10 list=LAN_NB
/ip address
add address=192.168.10.1/24 interface=LAN network=192.168.10.0
add address=172.16.0.1/24 interface=vlan10 network=172.16.0.0
/ip cloud
set ddns-enabled=yes
/ip dhcp-client
add add-default-route=no disabled=no interface=pppoe-out2
/ip dhcp-server lease
add address=192.168.10.244 client-id=1:74:83:c2:40:4:47 mac-address=
74:83:C2:40:04:47 server=dhcp1
add address=192.168.10.100 client-id=1:8c:89:a5:4c:1c:90 mac-address=
8C:89:A5:4C:1C:90 server=dhcp1
add address=192.168.10.161 client-id=1:bc:4c:c4:ab:e8:50 mac-address=
BC:4C:C4:AB:E8:50 server=dhcp1
add address=192.168.10.77 client-id=1:0:24:8c:7a:48:ec mac-address=
00:24:8C:7A:48:EC server=dhcp1
add address=192.168.10.56 client-id=1:0:26:2d:4f:24:99 mac-address=
00:26:2D:4F:24:99 server=dhcp1
add address=192.168.10.189 client-id=1:48:bf:6b:6a:70:6e mac-address=
48:BF:6B:6A:70:6E server=dhcp1
add address=192.168.10.157 client-id=1:3c:dc:bc:f9:59:27 mac-address=
3C:DC:BC:F9:59:27 server=dhcp1
add address=192.168.10.162 client-id=1:fc:e9:98:8d:37:1 mac-address=
FC:E9:98:8D:37:01 server=dhcp1
add address=192.168.10.4 client-id=1:24:79:f3:a4:78:d1 mac-address=
24:79:F3:A4:78:D1 server=dhcp1
add address=192.168.10.160 client-id=1:c0:d0:12:74:f:f1 mac-address=
C0:D0:12:74:0F:F1 server=dhcp1
add address=192.168.10.200 client-id=1:0:1e:65:de:a0:ea mac-address=
00:1E:65:DE:A0:EA server=dhcp1
add address=192.168.10.163 client-id=1:c0:1a:da:55:e3:4f mac-address=
C0:1A:DA:55:E3:4F server=dhcp1
add address=192.168.10.94 client-id=1:1c:6f:65:e6:88:76 mac-address=
1C:6F:65:E6:88:76 server=dhcp1
/ip dhcp-server network
add address=172.16.0.0/24 dns-server=8.8.8.8,8.8.4.4 gateway=172.16.0.1
add address=192.168.10.0/24 dns-server=8.8.8.8,8.8.4.4 gateway=192.168.10.1
/ip dns
set servers=8.8.8.8,8.8.4.4
/ip firewall address-list
add address=172.16.0.0/16 list=LAN
add address=192.168.10.0/24 list=LAN
/ip firewall mangle
add chain=prerouting comment="accept traffic from lan" dst-address-list=LAN
src-address-list=LAN
add action=mark-connection chain=input comment=
"traffic from internet to wan port" connection-mark=no-mark in-interface=
pppoe-out1 new-connection-mark=internet-to-isp1 passthrough=no
add action=mark-connection chain=input connection-mark=no-mark in-interface=
pppoe-out2 new-connection-mark=internet-to-isp2 passthrough=no
add action=mark-routing chain=output connection-mark=internet-to-isp2
new-routing-mark=isp2-to-internet passthrough=no
add action=mark-routing chain=output connection-mark=internet-to-isp1
new-routing-mark=isp1-to-internet passthrough=no
add action=mark-connection chain=forward connection-mark=no-mark
in-interface=pppoe-out2 new-connection-mark=internet-isp2-lan
passthrough=no
add action=mark-routing chain=prerouting connection-mark=internet-isp1-lan
in-interface-list=LAN_NB new-routing-mark=isp1-to-internet passthrough=no
src-address-list=LAN
add action=mark-routing chain=prerouting connection-mark=internet-isp2-lan
in-interface-list=LAN_NB new-routing-mark=isp2-to-internet passthrough=no
src-address-list=LAN
add action=mark-connection chain=prerouting comment="PCC rules"
connection-mark=no-mark dst-address-list=!LAN dst-address-type=!local
in-interface-list=LAN_NB new-connection-mark=lan-to-isp1 passthrough=yes
per-connection-classifier=both-addresses:2/0 src-address-list=LAN
add action=mark-connection chain=prerouting connection-mark=no-mark
dst-address-list=!LAN dst-address-type=!local in-interface-list=LAN_NB
new-connection-mark=lan-to-isp2 passthrough=yes
per-connection-classifier=both-addresses:2/1 src-address-list=LAN
add action=mark-routing chain=prerouting connection-mark=lan-to-isp1
dst-address-list=!LAN in-interface-list=LAN_NB new-routing-mark=
isp1-to-internet passthrough=no src-address-list=LAN
add action=mark-routing chain=prerouting connection-mark=lan-to-isp2
dst-address-list=!LAN in-interface-list=LAN_NB new-routing-mark=
isp2-to-internet passthrough=no src-address-list=LAN
/ip firewall nat
add action=masquerade chain=srcnat out-interface=pppoe-out1
add action=masquerade chain=srcnat out-interface=pppoe-out2
/ip route
add distance=1 gateway=192.168.1.100 routing-mark=isp2-to-internet
add check-gateway=ping distance=1 gateway=pppoe-out1 routing-mark=
isp1-to-internet
add check-gateway=ping distance=1 gateway=pppoe-out1
add check-gateway=ping distance=2 gateway=192.168.1.100
/ip service
set telnet disabled=yes
set ftp disabled=yes
set ssh disabled=yes
set api disabled=yes
set api-ssl disabled=yes
/system clock
set time-zone-name=Asia/Ho_Chi_Minh
i have shown configuration below the comments, you can see
i dont understand. 
Something new?