Internet Speed Test Slower with USB NIC installed and internal and external NICs active

  1. Hello!

Has anyone installed a USB nic into their Pi to use as a second network interface? I just did it for a project, rebooted, and the Pi’s results from cli-speedtest are about 30-50 Mbps slower than they were before. Results on another computer report the usual speed.

Both the internal and USB NIC are recognized–both have network addresses.

I’m guessing the internal NIC and the USB NIC are competing to grab data during the test, which is slowing things down.

Do I need to configure something to ensure the Pi gets the max possible speed again?

Alternatively, is it possible my router, which was beefy in 2017 but is still a 1Gbps router, is struggling with a single computer having two NICs and doing things?

Note: I’m expecting ~230 Mbps using the command line speediest utility, and seeing between 170-200. This is not a problem, per se, but a signal something may be misconfigured.

This is what I’m seeing for Ethernet interfaces:

2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether $MAC brd ff:ff:ff:ff:ff:ff
inet $ADDRv4/24 brd 192.168.1.255 scope global dynamic noprefixroute eth0
valid_lft 82744sec preferred_lft 82744sec
inet6 $ADDRv6/64 scope global dynamic noprefixroute
valid_lft 604399sec preferred_lft 604399sec
inet6 $ADDRv6local/64 scope link noprefixroute
valid_lft forever preferred_lft forever

4: enp1s0u1u1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether $MAC brd ff:ff:ff:ff:ff:ff
inet $ADDRv4/24 brd 192.168.1.255 scope global dynamic noprefixroute enp1s0u1u1
valid_lft 82743sec preferred_lft 82743sec
inet6 $ADDRv6/64 scope global dynamic noprefixroute
valid_lft 604399sec preferred_lft 604399sec
inet6 $ADDRv6local/64 scope link noprefixroute
valid_lft forever preferred_lft forever