Community discussions

MikroTik App
 
roe1974
Member Candidate
Member Candidate
Topic Author
Posts: 133
Joined: Mon Dec 31, 2018 2:14 pm

RSTP or HW offload on a RB4011iGS+

Wed Oct 13, 2021 4:23 pm

Hello

I have a question about the bridge/RSTP/HW offload on the RB4011iGS+.
I use the router in a home network. Devices like NAS, Raspberry, Cam etc. hang on the ports.
Is it better to disable RSTP in this scenario so that the hardware offload can be enabled ... or better to leave RSTP active ?
Thanks for your help/opinion

greetings Richard
 
User avatar
rushlife
Member Candidate
Member Candidate
Posts: 180
Joined: Thu Nov 05, 2015 12:30 pm
Location: czech republic

Re: RSTP or HW offload on a RB4011iGS+

Wed Oct 13, 2021 5:26 pm

hi, if you do not use spanning tree in your home network, rstp is not so mandatory for your use case and hw offload can be handy for forwarding traffic between ports on router without unpleasant cpu load

otherwise if you have multiple traces for switches and active loop protect, rstp / stp can be handy
 
roe1974
Member Candidate
Member Candidate
Topic Author
Posts: 133
Joined: Mon Dec 31, 2018 2:14 pm

Re: RSTP or HW offload on a RB4011iGS+

Wed Oct 13, 2021 5:57 pm

The CPU Load is now (RSTP activated) about 4-6% (at peak times) ... not more ... so no need for HW-offload ?
br, Richard
 
tdw
Forum Guru
Forum Guru
Posts: 1020
Joined: Sat May 05, 2018 11:55 am

Re: RSTP or HW offload on a RB4011iGS+

Wed Oct 13, 2021 9:17 pm

Hardware offload only applies to traffic between ports on the same switch chip, e.g. backing up a PC to a NAS on the same LAN, anything between switch chips or from LAN to WAN is always handled by the CPU. Data paths are shown on the block diagram https://i.mt.lv/cdn/product_files/RB401 ... 180903.png

According to https://help.mikrotik.com/docs/display/ ... Offloading the RTL8367 used in the RB4011 supports hardware offload with STP/RSTP or MSTP enabled.
 
roe1974
Member Candidate
Member Candidate
Topic Author
Posts: 133
Joined: Mon Dec 31, 2018 2:14 pm

Re: RSTP or HW offload on a RB4011iGS+

Wed Oct 13, 2021 9:59 pm

thanks for the info @tdw
HW offload is enabled on ports but it is not activated.
When I disable RSTP the HW offload is activated.
According to wiki it looks different for the RTL8367 ... see:

https://wiki.mikrotik.com/wiki/Manual:I ... Offloading

greetings Richard
 
mkx
Forum Guru
Forum Guru
Posts: 6631
Joined: Thu Mar 03, 2016 10:23 pm

Re: RSTP or HW offload on a RB4011iGS+

Wed Oct 13, 2021 10:40 pm

The problem with MT documentation is that it mostly documents state of art according to most recent ROS version at the moment of writing/updating (and documentation is not necessarily always up-to-date) and often doesn't mention version when certain feature got implemented.

In particular: RT switch chip in RB4011 had extremely poor support until around ROS 6.47. Which is what wiki documents. With ROS 7.1 it got decent support and that's what docs documents. Could be MT improved parts of support in recent 6.xx versions but not as exhaustively as in 7.1 (nah, that's probably not it do who knows where the info about RSTP with HW offload came from, possibly a copy-paste error). Funny thing is there's a remark about VLAN HW support starting with 7.1 but no such remark regarding MSTP which is inherently a VLAN stuff (in theory not so much but in practice for non-VLAN deployments MSTP is mostly not necessary, RSTP does the trick).
Now it really depends on particular ROS version @OP is running on his RB4011 ... Personaly I wouldn't go for 7.1 on any device used anything but as lab test unit. Which means the safest way of getting decent performance is to disable RSTP unless OP really really needs it due to network topology.
BR,
Metod

Who is online

Users browsing this forum: Drean, hahnhell, to55603 and 20 guests