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sebus
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Bridge Mode & DHCP

Sat Sep 05, 2020 8:16 pm

Had to emergency connect 4G router to Mikrotik WAN port - ether1 (because ISP fibre connection died due to cables being cut some place else)
As the 4G Huawei router provides DHCP, it was easiest to configure in bridged mode.

But I would expect that this would automatically disable DHCP on Mikrotik ether2-master bridge (maybe wrong assumption, or maybe I did not select some settings while settings Bridged connection)
What I ended up with was some devices obtaining IP from 4G router fine, some getting nothing at all, some getting most odd like 0.0.0.2 255.0.0.0

Had to manually disable defcon DHCP server. Once done all dhcp request were dealt with by 4G router

So the question is: is that expected behaviour?

sebus
 
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xvo
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Re: Bridge Mode & DHCP

Sat Sep 05, 2020 9:37 pm

If you didn't disable it yourself, mikrotik won't do it for you, that's for sure.

On the other hand, if talking about "bridge mode", you mean quickset, then I'm going to disappoint you: quickset is not meant to be used on the router, that has a non-default configuration. I mean at all. It can screw you configuration in an hardly predictable way (the exact situation you found yourself in).
 
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krafg
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Re: Bridge Mode & DHCP

Sat Sep 05, 2020 9:51 pm

If Huawei router and your routerboard have different IP sections not should be a problem with both DHCP's enabled.

Huawei DHCP enabled.
Mikrotik WAN port -> DHCP client enabled.
Mikrotik LAN port -> DHCP server enabled.

Regards.
 
sebus
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Re: Bridge Mode & DHCP

Sat Sep 05, 2020 10:00 pm

@krafg

Thanks, but you did not understand, so the one above it a "better" option.

@xvo

non-default configuration I assume would be just "blank" OS with zero configuration.
Anyway, I would expect some logic build in, so user does not do something that "should not" happen.
That is what I normally expect from the gear I work with. But well...
 
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xvo
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Re: Bridge Mode & DHCP

Sat Sep 05, 2020 11:18 pm

That is what I normally expect from the gear I work with. But well...
Quickset is just a set of scripts, that apply different predefined configurations with some user-defined variables (like names, passwords, some checkbox-type options).
There is absolutely no way someone could make such script check all possible collisions with already written configuration.

So two behaviours are theoretically possible: to overwrite the whole configuration, or to overwrite only fields, that are relevant to current quickset template.
I, personally, would prefer it to go with removing the whole configuration (with a warning, of course).
But for some reason it is not the case.
So you end up with leftovers from the previous config.
 
sebus
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Re: Bridge Mode & DHCP

Sun Sep 06, 2020 9:19 am

Maybe a warning while using Quickset after initial config would make sense.

I also noticed that it randomly removed me a couple of firewall rules for L2TP/IPsec server access

Not being told what will happen, is not the "safest" design.

sebus
 
jarda
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Re: Bridge Mode & DHCP

Sun Sep 06, 2020 9:47 am

It's somehow written in documentation already:
https://wiki.mikrotik.com/wiki/Manual:Quickset#F.A.Q

But should be more obvious, I admit, because many people mix the quickset with other configuration ways.

There should be some consistency check implemented that would forbid to use quickset if the actual configuration is out of its range.
 
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xvo
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Re: Bridge Mode & DHCP

Sun Sep 06, 2020 10:00 am

Maybe a warning while using Quickset after initial config would make sense.

I also noticed that it randomly removed me a couple of firewall rules for L2TP/IPsec server access

Not being told what will happen, is not the "safest" design.

sebus
While there are some warnings in help web page for quickset, there are indeed no warnings in the script itself.
I agree that a popup message or just a remark in red on the bottom of the window would be a good addition.
 
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anav
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Re: Bridge Mode & DHCP

Sun Sep 06, 2020 8:50 pm

Concur, it should say if you are using quickset to config your router, do not stop on go, do not collect $200 go directly to jail. ;-)
 
sebus
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Re: Bridge Mode & DHCP

Sun Sep 06, 2020 8:59 pm

And that is the answer from Guru...
 
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anav
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Re: Bridge Mode & DHCP

Sun Sep 06, 2020 11:12 pm

I should add my byline, which is ASCERBIC LLAMA. if you cannot laugh while configuring an MT router, you will die at a young age.
Hey compared with my good looks, fetid hot breath and flatulence, only perhaps Chapuka has similar physical aesthetic appeal. Sorry xvo!

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