BGP configuration and performance of flow problem.

Hi
I’m an advanced user on Mikrotik systems. After more than six months reflecting on the run BGP based on the MK, I replaced my Cisco 3825 to CCR1036-12G-4S ((RouterOS v6.19). I have two ISP with a full array of BGP. The first ISP: symmetrical 200Mb/s, second ISP 100Mb/s.

I have a subtle problems of IP flows.

symptoms:

  • Very often you can not complete download large files (over 500MB)
  • Speedtest.net - at 95% download, tip begins to gently fall (by 2s) and oscillates around 90Mbit / s + - delta 0,5Mbit, and the test never ends. This is repeated every time. It looks as if some bandwidth limiter, which does not exist.
  • Consist website loaded slowly
  • Some web pages do not make at all. The page structure is broken.

From the beginning I had implemented PCQ but in order to eliminate possible causes I led to a clean, simplest configuration. Only IP routing with BGP.
I have no problems with BGP as such.

I verified ISP - it’s not their problem.
I checked the CPU Mikrotik - is quite ok - one core is sometimes busy in the range of 60-100%, I think of it is responsible for the GUI of WinBox. ALL system uses 800MB of 4GB RAM.

I would add that, as I’ll put back the CISCO router everything back to order.

It looks like a performance problem of fast flow, the problem of buffers/CPU on MK.

Any ideas?

We have a very similar setup, however our 1st link is 200Mbps and the other 1Gbps (full duplex).

Are you connecting to the ISPs by SFP or Ethernet?

It could be a mismatch of speeds, one end could be running at half duplex and the other at full. Your ISP may require that you fix your speed as opposed to auto-negotiation.

Also make sure Flow Control is switched off in both directions on the interface.

We have:

2 x CCR 16gb ram same as below on each BGP
v6.12

1 x copper 100mb flow control off auto negotiation on
1 x fibre 1 gig speed fixed 1 gig flow control off (this link did not work on auto negotiation)

No issues

regards
Tony