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archerious
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Bridging vs Switching on CRS3xx series?

Mon May 18, 2020 11:47 pm

I know the CRS3xx series uses hw offload on the bridge vlan method, but what confuses me is the performance tests on Mikrotik's site. For example on CRS309:

https://mikrotik.com/product/crs309_1g_ ... estresults

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CCR2004, RB4011 Former: hEX (RB750Gr3), ER4
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bpwl
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Re: Bridging vs Switching on CRS3xx series?

Mon May 18, 2020 11:59 pm

Did they play it safe? Test without HW offloading?

Warning: Currently it is possible to create only one bridge with hardware offloading on CRS3xx series devices. Use the hw parameter to select which bridge will use hardware offloading.
https://wiki.mikrotik.com/wiki/Manual:C ... s_switches
 
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archerious
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Re: Bridging vs Switching on CRS3xx series?

Tue May 19, 2020 12:05 am

Did they play it safe? Test without HW offloading?

Warning: Currently it is possible to create only one bridge with hardware offloading on CRS3xx series devices. Use the hw parameter to select which bridge will use hardware offloading.
https://wiki.mikrotik.com/wiki/Manual:C ... s_switches
What confuses me, I have one bridge, with hw offload on, does that mean at best my 64 bytes performance is 124.7Mbps or 61,714.3Mbps?
CCR2004, RB4011 Former: hEX (RB750Gr3), ER4
Aruba 2930F, CSS326, CRS309, CRS112-PoE Former: Ubiquiti XG-16 & ES-10X
Wireless Wire
AT&T Fiber 1000/1000
http://tlopez.cc/images/hex_is_a_beast.PNG
http://tlopez.cc/images/ccr2004_speedtest.png
 
Paternot
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Re: Bridging vs Switching on CRS3xx series?  [SOLVED]

Tue May 19, 2020 2:18 am

Bridging is not switching.

When switching all the traffic pass through the switch chip, and that's it.
When bridging the traffic passes through the CPU. It does little more than copying the packets from one port to another - but it crosses the CPU.

To be clear: switching takes place inside the switch chip. The way Mikrotik joins ports on a switch chip is through a bridge - but this is NOT bridging. At least, not in Mikrotik parlance.
What they cal "bridging" would be like creating a software bridge on a router WITHOUT switch chip (say a CCR1009-7G-1C-PC), and slaving several interfaces to this bridge. THEN, "bridging" would refer to the traffic between these ports.

You do "switching" when the router have a switch chip, some ports are added to the "bridge" created on it, and traffic passes from one port to another. In this case the CPU sees nothing - it goes only through the switch chip.

Yes, yes. Confusing, I know.
 
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archerious
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Re: Bridging vs Switching on CRS3xx series?

Tue May 19, 2020 5:17 am

Bridging is not switching.

When switching all the traffic pass through the switch chip, and that's it.
When bridging the traffic passes through the CPU. It does little more than copying the packets from one port to another - but it crosses the CPU.

To be clear: switching takes place inside the switch chip. The way Mikrotik joins ports on a switch chip is through a bridge - but this is NOT bridging. At least, not in Mikrotik parlance.
What they cal "bridging" would be like creating a software bridge on a router WITHOUT switch chip (say a CCR1009-7G-1C-PC), and slaving several interfaces to this bridge. THEN, "bridging" would refer to the traffic between these ports.

You do "switching" when the router have a switch chip, some ports are added to the "bridge" created on it, and traffic passes from one port to another. In this case the CPU sees nothing - it goes only through the switch chip.

Yes, yes. Confusing, I know.
Thank you, that makes the most sense. I always wondered if that was the case but it just seemed to odd. I tested a hEX and noticed that the bridge vlan method used software and caused poorer performance. What you said makes sense, they consider bridging using software/no hw offload, and switching = with hw offload on.

I appreciate your time here, helped me a lot.
CCR2004, RB4011 Former: hEX (RB750Gr3), ER4
Aruba 2930F, CSS326, CRS309, CRS112-PoE Former: Ubiquiti XG-16 & ES-10X
Wireless Wire
AT&T Fiber 1000/1000
http://tlopez.cc/images/hex_is_a_beast.PNG
http://tlopez.cc/images/ccr2004_speedtest.png
 
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mutluit
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Re: Bridging vs Switching on CRS3xx series?

Tue May 19, 2020 1:19 pm

@archerious, see also https://wiki.mikrotik.com/wiki/Manual:I ... Offloading :
Bridge Hardware Offloading
Since RouterOS v6.41 it is possible to switch multiple ports together if a device has a built-in switch chip. While a bridge is a software feature that will consume CPU's resources, the bridge hardware offloading feature will allow you to use the built-in switch chip to forward packets, this allows you to achieve higher throughput, if configured correctly.
For me "bridging" on such a CRS3xx device simply means "grouping of ethernet ports" :-) One can remove (and put back) interfaces in that group.

The documentation says that currently only one bridge can make use of the "Hardware Offloading capability of the ASIC switch-chip": https://wiki.mikrotik.com/wiki/Manual:C ... _switching

Another important factor is the number of ACL rules one can define (ie. the number of hardware firewall rules one can define):
https://wiki.mikrotik.com/wiki/Manual:C ... hes#Models
For the CRS326 that number is 128. For my needs that's more than sufficient as I currently have only 17 such ACL rules.
 
ste
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Re: Bridging vs Switching on CRS3xx series?

Tue May 19, 2020 8:30 pm

Bridging is not switching.

When switching all the traffic pass through the switch chip, and that's it.
When bridging the traffic passes through the CPU. It does little more than copying the packets from one port to another - but it crosses the CPU.

To be clear: switching takes place inside the switch chip. The way Mikrotik joins ports on a switch chip is through a bridge - but this is NOT bridging. At least, not in Mikrotik parlance.
What they cal "bridging" would be like creating a software bridge on a router WITHOUT switch chip (say a CCR1009-7G-1C-PC), and slaving several interfaces to this bridge. THEN, "bridging" would refer to the traffic between these ports.

You do "switching" when the router have a switch chip, some ports are added to the "bridge" created on it, and traffic passes from one port to another. In this case the CPU sees nothing - it goes only through the switch chip.

Yes, yes. Confusing, I know.
From a networkers standpoint a switch is a multiport bridge. Configuring a bridge with more than 2 ports with MT it is infact a switch.
The other thing is wether bridging/switching is done with cpu or special asics.
 
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Re: Bridging vs Switching on CRS3xx series?

Wed May 20, 2020 2:20 am


From a networkers standpoint a switch is a multiport bridge. Configuring a bridge with more than 2 ports with MT it is infact a switch.
The other thing is wether bridging/switching is done with cpu or special asics.
From a network standpoint, no doubt. The problem here is Mikrotik's parlance. We have "bridge" as "ports connected through a switch" and "bridging", as "moving one ethernet datagram from one interface to another, through the CPU". It IS confusing: because, according to these terms, a "bridge" don't do "bridging". It is maddening... :D
 
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Re: Bridging vs Switching on CRS3xx series?

Wed May 20, 2020 7:27 pm

But then Mikrotik bridges are not simple switches. Switching implies all ports are based on same L1 technology (i.e. wired ethernet) while mikrotik bridges can span different technologies (e.g. wireless interfaces, lte interfaces, vlan pseudo-interfaces, ...).

Besides, wikipedia article about bridging doesn't limit number of ports to 2. Further more, from description of what bridge is follows conclusion that ethernet switch is just a special case of network bridge.
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Re: Bridging vs Switching on CRS3xx series?

Wed May 20, 2020 7:29 pm

The problem here is Mikrotik's parlance. We have "bridge" as "ports connected through a switch" and "bridging", as "moving one ethernet datagram from one interface to another, through the CPU".

Actually Mikrotik wants you to forget about switches inside their devices ... they do bridges and some ports have HW-offloaded operations.
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anav
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Re: Bridging vs Switching on CRS3xx series?

Wed May 20, 2020 8:09 pm

The problem here is Mikrotik's parlance. We have "bridge" as "ports connected through a switch" and "bridging", as "moving one ethernet datagram from one interface to another, through the CPU".

Actually Mikrotik wants you to forget about switches inside their devices ... they do bridges and some ports have HW-offloaded operations.
Is that your final answer Jamal mkx??

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