Dear MikroTik Community,
I have a problem with getting IP address from my ISP.
What could be the problem?
Very often, the Internet disappears for a short time, and then reappears. Previously, this did not happen 
I’m new to router OS.Thank’s guys. And sorry , my english bad
Config? Maybe you’re blocking important DHCP packets with the firewall.
try to disable your firewall drop rules and keep an eye on it it must be fine…
Bad cable between ISP device and router?
FW rules (input chain rules are interfering).
Hard to say when one doesn’t post their config!!!
/export hide-sensitive file=yourconfig
My config:
myconfig.rsc (3.43 KB)
What is connected to ether1?
My ISP gives the IP address - DHCP.
And i have second ISP with static IP. Static work fine.
First in reply you only have ether1 listed as part of your WAN (interface members list) but you are stating two ISPs???
Secondly your IP address is incorrect.
/ip address
add address=192.168.88.1/24 comment=defconf interface=ether2 network=
should be
/ip address
add address=192.168.88.1/24 comment=defconf interface=bridge network=\
Thirdly if you have a second ISP then you need two sourcenat rules.
/ip firewall nat
add action=masquerade chain=srcnat comment=“defconf: masquerade”
ipsec-policy=out,none out-interface=ether1 (for the dynamic ISP)
Plus an action=src-nat chain=srcnat rule for the fixed static ISP IP.
Also your DNS is in slight conflict and needs to be cleaned up.
/ip dhcp-server network
add address=192.168.88.0/24 comment=defconf gateway=192.168.88.1 dns=192.168.88.1
/ip dns
set allow-remote-requests=yes servers=8.8.8.8,1.1.1.1
/ip dns static
add address=192.168.88.1 name=router.lan Remove this static line its a quickset config that you dont need.
Both on same interface?
Yes, I connected another provider today. He has a static ip on WAN. And work perfectly.
But why is my main provider has DHCP on WAN and don’t work correctly.
Log screenshot before connected second provider.I just reconfigured eth1 to static ip.And internet work perfectly.
Personally, I would just run the sniffer which will give all answers:
/tool sniffer start interface=ether1-uplink port=68
and after some time (look at logs and wait until you lose and reacquire your IP few times)
/tool sniffer save file-name=dhcp.pcap
/tool sniffer stop
In the file, there will be DHCP packets captured. You can download it to your computer and use tools like Wireshark to read it.
Packets should go same way as described here: https://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol#Operation
If they aren’t in the same order, some packet is missing or some is repeated many times, it points to the issue. Skilled person should instantly know whats going on.
Usual reason is, that either client or server miss some packet and does not reply.
If you are unsure what to do with the recorded file, you may show it to someone more experienced or upload it here as attachment.
If you worry about not publishing your IP, well, you already did, because anyone with piece of brain can figure it out from your screenshot.
My snif
mysniff.rar (87.4 KB)