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nutsBo
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CRS354 in Router OS, single box WAN/LAN solution

Tue Nov 01, 2022 9:32 pm

hello networking friends,

i own an MikroTik CRS354-48G-4S+2Q+RM and run the device as a simple VLAN switch at the moment (switch OS active).
In front of the CRS354 is an router what connects my two WAN modems to the LAN.
My goal: swap to an single box design an remove the old router in between.

I am not so skilled in MikroTik configurations and looking for some help about it.
The MikroTik need to handle the features below to work successful for me:

Dual WAN Failover (DHCP to WAN Modems) eth1 & eth2
Dynamic DNS
VPN L2TP over IPsec
NAT Firewall
DHCP server for each VLAN
VLAN 1
VLAN 2
VLAN 3 (Guest VLAN, no router management and VLAN isolation. WEB access, icmp, dhcp, ntp, dns only)


Is there any config generator available to creat a basic starting file for this?
What will be the simple way to get this config done?

best regards
nut
 
mkx
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Re: CRS354 in Router OS, single box WAN/LAN solution

Tue Nov 01, 2022 10:00 pm

While CRS can perform all functions ROS can, it can perform only a few functions at wire speed. This mainly includes routing and some limited firewalling. The rest (e.g. VPN, the rest of firewalling) is left to weak CPU and will perform poorly, on the level of slowest small routers by MT (e.g. lower than RB951Ui). I.e. if your setup will not be suitable for L3HW offloading, cumulative routing speed will be around 170Mbps (give or take, depends on exact config).
 
nutsBo
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Re: CRS354 in Router OS, single box WAN/LAN solution

Wed Nov 02, 2022 12:51 am

@mkx
Phew!!! don't see this comming :shock:
So you point to the routing betwenn WAN and LAN oder just between the VLANs of the CRS !?!
If WAN to LAN is affected this setup make no sence anymore. My primary WAN is a Gigabit Access and become a shame line due to this.....
 
mkx
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Re: CRS354 in Router OS, single box WAN/LAN solution

Wed Nov 02, 2022 8:39 am

Have a look at article on L3 HW offloading. Check how your actual use case and your hardware fits. Your device is on more capabke end if device list so things might work after all. I'm a bit hesitant when it comes to multi-WAN, but I guess it's possible to arrange things to be HW offloaded. So do read throughly the linked artucle. When in doubt, ask here, somebody might give you some insight. If, after that, you won't be sure that all fits together, then most likely it won't.

The reason I brought up the performance issue is the huge difference in performance when L3HW offload doesn't work. So you really have to do things perfectly right to have router perform wirespeed - if router doesn't have L3HW support, then non-optimal config might incur something like 10% performance penalty, in this case penalty would be one order of magnitude.
 
nutsBo
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Re: CRS354 in Router OS, single box WAN/LAN solution

Wed Nov 02, 2022 8:49 pm

L3HW offloading is actice in my lan setup.
I do WAN failover only. No load-balancing is need for me. Have a cable and mobile modem in place so the router must just switch between both if needed.
My routing requirements also low. yes 3 vlans but one is for guests without inter vlan routing. 99% of the traffic run in vlan1 untagged. vlan2 is just a small lab/test area with low traffic.
I think it must be possible to route up to gigabit traffic from wan to 1 or 2 clients in vlan1 or not ?!

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