Very slow network after installation

I just installed Tumbleweed and my network connection is now very slow: only 300kB/s max. (I am sure it is not a network issue). Can someone please help with this? Thanks!

Wired or wireless connectivity? NIC hardware details and if using ethernet then ‘ethtool’ output would be useful to start with.

/usr/sbin/hwinfo --netcard

If using NetworkManager, the following recent thread may be relevant here…
https://forums.opensuse.org/showthread.php/533124-Slow-internet-on-Tumbleweed-compared-to-Fedora

It happens both with wired and wireless.

07: PCI 300.0: 0282 WLAN controller
  [Created at pci.378]
  Hardware Class: network
  Model: "Dell Inspiron M5010 / XPS 8300"
  Vendor: pci 0x14e4 "Broadcom"
  Device: pci 0x4727 "BCM4313 802.11bgn Wireless Network Adapter"
  SubVendor: pci 0x1028 "Dell"
  SubDevice: pci 0x0010 "Inspiron M5010 / XPS 8300"
  Revision: 0x01
  Driver: "bcma-pci-bridge"
  Driver Modules: "bcma"
  Device File: wlp3s0b1
  Features: WLAN
  Memory Range: 0xe6600000-0xe6603fff (rw,non-prefetchable)
  IRQ: 17 (73669 events)
  Link detected: yes
  WLAN channels: 1 2 3 4 5 6 7 8 9 10 11 12 13
  WLAN frequencies: 2.412 2.417 2.422 2.427 2.432 2.437 2.442 2.447 2.452 2.457 2.462 2.467 2.472
  WLAN encryption modes: WEP40 WEP104 TKIP CCMP
  WLAN authentication modes: open sharedkey wpa-psk wpa-eap
  Module Alias: "pci:v000014E4d00004727sv00001028sd00000010bc02sc80i00"
  Driver Info #0:
    Driver Status: bcma is active
    Driver Activation Cmd: "modprobe bcma"
  Config Status: cfg=no, avail=yes, need=no, active=unknown
  Attached to: #22 (PCI bridge)

19: PCI 19.0: 0200 Ethernet controller
  [Created at pci.378]
  Hardware Class: network
  Device Name: "Onboard LAN"
  Model: "Intel 82579LM Gigabit Network Connection"
  Vendor: pci 0x8086 "Intel Corporation"
  Device: pci 0x1502 "82579LM Gigabit Network Connection"
  SubVendor: pci 0x1028 "Dell"
  SubDevice: pci 0x0494 
  Revision: 0x04
  Driver: "e1000e"
  Driver Modules: "e1000e"
  Device File: em1
  Memory Range: 0xe6700000-0xe671ffff (rw,non-prefetchable)
  Memory Range: 0xe6780000-0xe6780fff (rw,non-prefetchable)
  I/O Ports: 0x5040-0x505f (rw)
  IRQ: 27 (171 events)
  Link detected: no
  Module Alias: "pci:v00008086d00001502sv00001028sd00000494bc02sc00i00"
  Driver Info #0:
    Driver Status: e1000e is active
    Driver Activation Cmd: "modprobe e1000e"
  Config Status: cfg=no, avail=yes, need=no, active=unknown

It happens both with wired and wireless.

Ok, and what were you using to determine network speed at the time? Some kind of internet-based test? Ideally, to test NIC/network speed you would use iperf running on two hosts (one as server, the other as a client).

The thread I linked to was about strange ethernet negotiation set, which turned out to be be due to configuration in the NM connection profile (/etc/NetworkManager/system-connections/…). I wouldn’t expect such a setting would be relevant for a wifi connection though. Perhaps worth checking that anyway.

I was simply using the GNOME system monitor while loading websites and downloading some software updates. It is a significant difference from the normal I had before with Leap 42.2, so I did not bother to do a very precise speed test. I have dual boot on this computer and the other OS is working fine in this regard.
@deano_ferrari thanks for the help! I will take a closer look to the link you shared.

Ok, but that is not really an indication of network bandwidth - the observed throughput could be server-related for example.