Mikrotik block access to Microsoft Outlook 365 account

kris1 · Mon Oct 19, 2020 2:12 pm

Hi All

I have issue with my Mikrotik's it looks like theare are bloking access to Office365 account in my company or block access to proxy.
My Mikrotik is configured to work in Bridge mode on all ports, so it should work like normal swich in L2.
I tested 2 device RB760iGS (6.42.10) and RouterBOARD 750 r2 (6.42.10) and both have the same problem , Microsoft Outlook can not connect to Exchange - in status bar.
In my comopany wy use proxy server to access internet. I'm able to access to internet (web mail https://outlook.office365.com/mail/inbox etc.) form my PC and ping Lan IP and websites from Mikrotik.
I setup router with and without defaul Configuration, add extra firewall rules with no result.
Please help me resolve this problem and check my config maybe I missed something :

# software id = 108G-5ZDV
#
# model = RouterBOARD 750 r2
# serial number = 8B38xxxxxxxx
/interface bridge
add name=bridge1
/interface list
add name=WAN
add name=LAN
/interface wireless security-profiles
set [ find default=yes ] supplicant-identity=MikroTik
/ip hotspot profile
set [ find default=yes ] html-directory=flash/hotspot
/interface bridge port
add bridge=bridge1 interface=ether1
add bridge=bridge1 interface=ether2
add bridge=bridge1 interface=ether3
add bridge=bridge1 interface=ether4
add bridge=bridge1 interface=ether5
/interface bridge settings
set use-ip-firewall=yes use-ip-firewall-for-pppoe=yes \
    use-ip-firewall-for-vlan=yes
/interface list member
add interface=ether1 list=WAN
add interface=ether2 list=LAN
add interface=ether3 list=LAN
add interface=ether4 list=LAN
add interface=ether5 list=LAN
/ip address
add address=10.x.x.x/22 interface=bridge1 network=10.x.x.0
/ip dns
set allow-remote-requests=yes servers=10.x.x.x,10.x.x.x
/ip firewall filter
add action=accept chain=forward src-address=165.x.x.x
add action=accept chain=output src-address=165.x.x.x
add action=accept chain=forward dst-address=165.x.x.x
add action=accept chain=output dst-address=165.x.x.x
add action=accept chain=input dst-port=53 in-interface=bridge1 protocol=udp
add action=accept chain=input dst-port=53 in-interface=bridge1 protocol=tcp
add action=accept chain=input in-interface-list=all
add action=accept chain=output
add action=accept chain=forward in-interface-list=all
add action=accept chain=forward protocol=tcp src-port=995,993,587
add action=accept chain=input protocol=tcp src-port=995,993,587
add action=accept chain=output protocol=tcp src-port=995,993,587
/ip route
add distance=1 gateway=10.x.x.x
add distance=1 dst-address=10.x.x.0/22 gateway=bridge1

mkx · Mon Oct 19, 2020 7:57 pm

That's almost craziest firewall filter ruleset I've seen so far. And without any effect for that matter.

Anyway, if you want RB to act as ethernet switch, start off from an empty config, create a bridge and add all ethernet ports to it. No other bridge settings, no IP address, nothing.
At this point RB is a switch. If you can't access office365, then it's not RB blocking it, it's something else.

Moba · Mon Oct 19, 2020 9:04 pm

It's a config issue - I use Office 365 for work and have no problems accessing my account through ROS.

kris1 · Wed Oct 21, 2020 10:57 am

Thansk for suggestion but if reset Configuration to Default would be helpful that's great :). Like I said before I have already tried it:

/interface bridge
add name=bridge1
/interface wireless security-profiles
set [ find default=yes ] supplicant-identity=MikroTik
/interface bridge port
add bridge=bridge1 interface=ether1
add bridge=bridge1 interface=ether2
add bridge=bridge1 interface=ether3
add bridge=bridge1 interface=ether4
add bridge=bridge1 interface=ether5

After many tries I start setup like you said "creazy rules" :) because I have no idea whay Mikrotik act so strange. Any others switches dont have so kind of problem I tested HP/Aruba Cisco TP link Netgar etc.
When I connect to Mikrotik, Microsoft Outlook stops on Loading Profile and I need to disconnect Network Cable, to open application and after reconect Cable Outlook is "Trying to connect" :/
Does anyone have any ideas how to resolve this problem?

BR

erlinden · Wed Oct 21, 2020 11:18 am

Ehm..."6.42.10"???
You might want to consider upgrading both devices?

bpwl · Wed Oct 21, 2020 11:34 am

"I have issue with my Mikrotik's it looks like theare are bloking access to Office365 account in my company or block access to proxy."

Trying to bypass corporate security ????
If other switches work, then at least use the MKT as switch. All interfaces bridged is OK. But don't do
/interface bridge settings set use-ip-firewall=yes

In a corporate network under my supervision your switches would have stopped all your network access immediately !

sindy · Wed Oct 21, 2020 12:01 pm

If no DHCP server is set up on a Mikrotik acting as a mere bridge (i.e. also use-ip-firewall=no), and there are no bridge filter/nat rules, there is no reason why Office 365 should be affected selectively. So it looks like either a more generic problem which you have only noticed when connecting to O365. With such a simple configuration (transparent bridge), the only reason I can imagine is some L2 MTU one. So as @erlinden suggests, as the first step I'd updgrade to a current long-term RouterOS (which is 6.46.7 as of writing this), reset the configuration to default after the upgrade, and then disable the DHCP server on the bridge. Ignore ether1 for the moment, use any of the remaining etherX interfaces as the uplink and to connect your laptop, and try whether the access to the O365 works. If yes, you can go step by step towards your desired configuration, checking that the login to O365 is still possible after each step.

kris1 · Wed Oct 21, 2020 2:12 pm

Finally, good news, I find root cause of the problem :)

Today I did a little investigation :) and it turned out that the problem does not affect all computers.
The virtual network card added by VirtualBox (6.0.4-128413) turned out to be problematic, I do not know how yet, but there is some dependence here with Mikrotik.

After disabling this Network Adapter, Outlook starts up and connect to Exchange :)

Very strange but WORKS :)

anav · Wed Oct 21, 2020 6:37 pm

So it had nothing to do with Mikrotik, you do know that you hurts its feelings...... :-(
MT may sue for slander!! ;-)
Thank god MT detected the anomaly and card fault, albeit not directly. :-)

In any case, keep your OS current is the one thing you should get out of this thread!!!

Mikrotik block access to Microsoft Outlook 365 account

Mikrotik block access to Microsoft Outlook 365 account

Re: Mikrotik block access to Microsoft Outlook 365 account

Re: Mikrotik block access to Microsoft Outlook 365 account

Re: Mikrotik block access to Microsoft Outlook 365 account

Re: Mikrotik block access to Microsoft Outlook 365 account

Re: Mikrotik block access to Microsoft Outlook 365 account

Re: Mikrotik block access to Microsoft Outlook 365 account

Re: Mikrotik block access to Microsoft Outlook 365 account

Re: Mikrotik block access to Microsoft Outlook 365 account

Who is online