Hello,

There is this setup as below where Internet was working just fine, but not anymore and I think it must be the Mikrotik as on Cisco router did not touch anything.

Cisco Router -- Switch -- Mikrotik (WAN IP) --- ISP

Cisco router is working as DHCP server configured on Vlan1 with config as below:
ip dhcp pool data
import all
network 192.168.10.0 255.255.255.0
default-router 192.168.10.254
dns-server 8.8.8.8 4.4.2.2

interface Vlan1
description $FW_INSIDE$
ip address 192.168.10.1 255.255.255.0
ip access-group 101 in
ip nat inside
ip virtual-reassembly in

Mikrotik has IP 192.168.10.254 and if a PC connected to the LAN port in Mikrotik, it gets the IP add in the range the router is giving 192.168.10.0/24 with gateway being 192.168.10.254 and DHCP server 192.168.10.1 and Internet was working fine.

ISP link with a public IP is on WAN port in Mikrotik.

This setup was working, and not sure what configuration was really into this Mikrotik (first time logged in via GUI) and it's quick set page showed this Mikrotik was working as CPE in bridged mode with public IP, mask, gateway and dns set statically. Bridge All Lan ports tick was NOT set.

After changing to new IPs from ISP set on Mikrotik in bridge mode, Internet didn't work, then tried to troubleshoot, set again the old IPs that Internet was working fine but no luck.
I can tell that from the PING tool on Mikrotik, PING works fine to 8.8.8.8 only from local-bridge interface! It doesn't work if ether1-gateway is selected.

Is there anything I'm missing in this Mikrotik setup? Basically Cisco Router is doing DHCP server and NAT, but not sure if additional NAT is required also in Mikrotik? Also should Mikrotik be working on router mode (maybe it changed it's mode when logged in GUI/maybe from the bug)?

Any help is highly appreciated!
Thanks!
R

Post the output of that please!