Framework Laptop 2.5Gbps Ethernet Expansion Card
Mixing 1Gbps, 2.5Gbps and 10Gbps has sort of been a nightmare for me on Mikrotik at least. My WAN port is 2.5Gbps and you would expect that I get full speed 112MB&#x2F;s Internet on the 1Gbps LAN ports, but that only happens if I force the WAN port to negotiate at 1Gbps. If I leave it at 2.5Gbps, then I get something like 50MB&#x2F;s instead, and it oscillates +- &gt;20MB&#x2F;s during the life of that TCP connection.<p>I don&#x27;t think it&#x27;s entirely a Mikrotik issue as I believe this is just a physics thing - you&#x27;re firing off one port at a certain speed so the buffer of the other port fills up too quickly unless the faster one slows down (resulting in excessive packet loss.) But it looks like Mikrotik has the most complaints about this.<p>The solution appears to be to enable Flow Control, but it&#x27;s never clear in which direction or which port it needs to be enabled on, and I haven&#x27;t really had any success with any combination.<p>[0] <a href="https:&#x2F;&#x2F;forum.mikrotik.com&#x2F;viewtopic.php?t=182691" rel="nofollow">https:&#x2F;&#x2F;forum.mikrotik.com&#x2F;viewtopic.php?t=182691</a><p>[1] <a href="https:&#x2F;&#x2F;forum.mikrotik.com&#x2F;viewtopic.php?t=181881" rel="nofollow">https:&#x2F;&#x2F;forum.mikrotik.com&#x2F;viewtopic.php?t=181881</a><p>[2] <a href="https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;mikrotik&#x2F;comments&#x2F;rq7ytu&#x2F;rb5009_25gbe_slower_than_1gbe&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;mikrotik&#x2F;comments&#x2F;rq7ytu&#x2F;rb5009_25g...</a><p>[3] <a href="https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;mikrotik&#x2F;comments&#x2F;rza5u3&#x2F;slow_multigigi_performance_on_rb5009&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;mikrotik&#x2F;comments&#x2F;rza5u3&#x2F;slow_multi...</a>