Routing vs Bridging + NAT performance on RB800

RouterOS General
1

I have a setup something like this:

ether1 – to internet using dhcp-client, so IP is totally random
ether2 – LAN interface with IP 10.0.1.1
wlan1 – another Wireless LAN interface with IP 10.0.2.1

Since I want client which connect to wlan1 will be able to talk to client on ether2, there is two possible ways I got it to work

  1. bridge ether2 and wlan1 and make them both use IP 10.0.1.3
  2. Masquerade NAT 10.0.2.0/24 (Wireless) to ether2 (LAN) 10.0.1.1

Since I am going to Masquerade NAT ether2 (LAN) to ether1 (Internet), I wonder given the selections above, which one will be faster in terms of NAT speed(Internet). According to http://www.routerboard.com/pdf/routerboard_performance_tests.pdf , bridging is faster than routing on RB800, is this true? I thought bridging is way slower.

The reason I am asking because the Internet line I am getting is a 1000mps line, which I really need to make sure the NAT from ether1 to ether2 is fast enough. (since I am not sure if point 1 above bridging will slow down the interface ether2 when I do NAT ether1 to ether2)

Thanks for any input.

2

My bridged performance between 2 ports on a rb450g topped out at about 200mbps, and it runs the atheros 680mhz and 256mb ram as i recal. I imagine bridging would probably top out at at least double that.

3

Ok, I end up testing it myself. The setup is like this…

Computer A (WAN) ---- RB800 ---- Computer B (LAN)

I make 1 computer act like the WAN while another computer act like the LAN. Both on Giga port + i7 CPU machine. The test was copying one 2G size file from computer B to computer A over SAMBA (windows)

Case 1

  • Computer A on ether2
  • Computer B on ether3
    With Bridging only (ether2 + ether3), it goes up to 800Mb/s Not bad.





Case 2

  • Computer A on ether2
  • Computer B on ether3
  • Wireless on wlan1

Bridge ether3 and wlan1 together and become “Bridge1”
“Bridge1” NAT to ether2. Therefore, clients of wireless and ether3 can go to the ether2 (WAN)
The speed top out at 480Mb/s AND RB800 CPU spike up to 100% , which is far below what this document indicate http://www.routerboard.com/pdf/routerboard_performance_tests.pdf




Case 3

  • Computer A on ether2
  • Computer B on ether3
  • Wireless on wlan1

wlan1 NAT to ether3, and then ether3 NAT to ether2 (WAN). Therefore, clients of wireless can go to ether3 and ether2. Clients of ether3 can go to ether2. No bridging at all.
The speed top out at 535Mb/s AND RB800 CPU spike up to 100%. It is still below the document indicate here http://www.routerboard.com/pdf/routerboard_performance_tests.pdf










I wonder if Mikrotik can comment on this? Did I miss anything? Thanks.

4

Any follow up about this NAT issue?

5