Slow internet on linux

Wired network extremely slow

At my office, we recently buy twenty laptops Dell Latitude 5420 under Ubuntu 20.04 and we have a big problem with ethernet connexion, download is extremly slow (but upload is good).

Edit: The problem is only on this laptop series, only with integrated ethernet and only on Ubuntu (see the tests below). Wifi is working perfectly, Ethernet is working perfectly too if we install Windows on this laptops and we don’t have problems if we use an Ethernet USB adapter or a dockstation with ethernet on it.

Type of internet connection used: VDSL2+
Download speed: 40,43 Mbps
Upload speed: 5,70 Mbps

Conditions of the tests performed at my office:

Type of internet connection used: Optical fiber
Download speed: 756,21 Mbps
Upload speed: 337,64 Mbps

Here are the tests I performed:

Ubuntu 20.04.1 LTS «Out Of The box»

Result after installation: Slow Ethernet (@home = download: 0,89 Mbps / upload : 4,82 Mbps)
Kernel version after installation: 5.6.0-1032-oem
Ethernet driver version after installation: Intel e1000e 3.2.6-k
Kernel version after update: 5.10.0-1029-oem
Ethernet driver version after update: Intel e1000e 5.10.0-1029-oem (driver included in the kernel)
Result after update: Slow Ethernet (@ home = download: 0,57 Mbps / upload : 4,61 Mbps)

Result after installation: Slow Ethernet (@home = download: 0,89 Mbps / upload : 4,82 Mbps) (@office = download : 6,36 Mbps / upload : 327,99 Mbps)
Kernel version after installation: 5.8.0-43-generic
Ethernet driver version after installation: Intel e1000e 3.2.6-k
Kernel version after update: 5.8.0-55-generic
Ethernet driver version after update: Intel e1000e 3.2.6-k
Result after update: Slow Ethernet (@home = download: 0,68 Mbps / upload : 4,52 Mbps) (@office = download : 5,31 Mbps / upload : 411,82 Mbps)
Unsuccessful attempts to manually install the 3.8.4 and 3.8.7 driver: Errors during driver compilation

Result on live session: Ethernet «a little less» slow (@home = download: 15,60 Mbps / upload : 4,41 Mbps)
Kernel version: 5.8.0-43-generic
Ethernet driver version: Intel e1000e 3.2.6-k

Result after installation: Card seen by the system but not claimed
Kernel version: 5.4.0-74-generic
Ethernet driver version: None
Kernel version after update: 5.4.0-74-generic
Ethernet driver version after update: None
Ethernet driver version after manual installation: 3.8.4-NAPI (downloaded from the Intel site)
Result after update: Ethernet ok (@home = download: 40,29 Mbps / upload : 5,37 Mbps)

Result after installation: Slow Ethernet (@home = download: 0,87 Mbps / upload : 4,73 Mbps)
Kernel version after installation: 5.6.0-1032-oem
Ethernet driver version after installation: Intel e1000e 3.2.6-k
Kernel version after update: 5.10.0-1029-oem
Ethernet driver version after update: Intel e1000e 5.10.0-1029-oem (driver included in the kernel)
Result after update: Slow Ethernet (@home = download: 0,56 Mbps / upload : 4,49 Mbps)
Unsuccessful attempts to manually install the 3.8.4 and 3.8.7 driver: Errors during driver compilation with kernels 5.6.0-1032-oem and 5.10.0-1029-oem

Result after installation: Slow Ethernet (@office = download: 1,52 Mbps / upload : 400,58 Mbps)
Kernel version after installation: 5.11.0-16-generic
Ethernet driver version after installation: 5.11.0-16-generic (driver included in the kernel)
Kernel version after update: 5.11.0-18-generic
Ethernet driver version after update: 5.11.0-18-generic (driver included in the kernel)
Result after update: Slow Ethernet (@office = download: 2,22 Mbps / upload : 410,05 Mbps)

Result after installation: Ethernet ok (@office = download: 850,12 Mbps / upload : 519,30 Mbps)

So, as we can see after all these tests, we can already exclude a hardware problem (the problem is present on 5 or 6 laptops tested out of the 20 laptops received) and the bandwidth is perfect on Ubuntu 18.04 once the Intel drivers are manually installed and on Windows.

At first, I think the solution would be to be able to install a more recent version of the «Intel e1000e» driver but when I try to compile it on the Ubuntu installed from the «Dell ISO», I get these errors (sorry for the French language) :

On kernel 5.6.0-1032-oem (from Dell ISO)

administrateur@administrateur-Latitude-5420:~/Téléchargements/e1000e-3.8.7/src$ sudo make *** The target kernel has CONFIG_MODULE_SIG_ALL enabled, but *** the signing key cannot be found. Module signing has been *** disabled for this build. make[1] : on entre dans le répertoire « /usr/src/linux-headers-5.6.0-1032-oem » CC [M] /home/administrateur/Téléchargements/e1000e-3.8.7/src/netdev.o In file included from /home/administrateur/Téléchargements/e1000e-3.8.7/src/e1000.h:14, from /home/administrateur/Téléchargements/e1000e-3.8.7/src/netdev.c:30: /home/administrateur/Téléchargements/e1000e-3.8.7/src/kcompat.h:825:2: error: #error UTS_UBUNTU_RELEASE_ABI is too large. 825 | #error UTS_UBUNTU_RELEASE_ABI is too large. | ^~~~~ make[2]: *** [scripts/Makefile.build:276: /home/administrateur/Téléchargements/e1000e-3.8.7/src/netdev.o] Erreur 1 make[1]: *** [Makefile:1707: /home/administrateur/Téléchargements/e1000e-3.8.7/src] Erreur 2 make[1] : on quitte le répertoire « /usr/src/linux-headers-5.6.0-1032-oem » make: *** [Makefile:73: default] Erreur 2

administrateur@administrateur-Latitude-5420:~/Téléchargements/e1000e-3.8.7/src$ sudo make *** The target kernel has CONFIG_MODULE_SIG_ALL enabled, but *** the signing key cannot be found. Module signing has been *** disabled for this build. make[1] : on entre dans le répertoire « /usr/src/linux-headers-5.10.0-1029-oem » CC [M] /home/administrateur/Téléchargements/e1000e-3.8.7/src/netdev.o In file included from /home/administrateur/Téléchargements/e1000e-3.8.7/src/e1000.h:14, from /home/administrateur/Téléchargements/e1000e-3.8.7/src/netdev.c:30: /home/administrateur/Téléchargements/e1000e-3.8.7/src/kcompat.h:825:2: error: #error UTS_UBUNTU_RELEASE_ABI is too large. 825 | #error UTS_UBUNTU_RELEASE_ABI is too large. | ^~~~~ make[2]: *** [scripts/Makefile.build:287: /home/administrateur/Téléchargements/e1000e-3.8.7/src/netdev.o] Erreur 1 make[1]: *** [Makefile:1849: /home/administrateur/Téléchargements/e1000e-3.8.7/src] Erreur 2 make[1] : on quitte le répertoire « /usr/src/linux-headers-5.10.0-1029-oem » make: *** [Makefile:73: default] Erreur 2

After reinstalling Ubuntu from the official ISO (not the Dell one) and disabled SecureBoot, I finally successfully installed the new Intel e1000e driver. but. the problem is still here.

On kernel 5.8.0-43-generic (from official Ubuntu ISO)

Result after 3.8.7 driver update: Slow Ethernet (@home = download: 0,16 Mbps / upload : 2,38 Mbps)

Result after 3.8.7 driver update: Slow Ethernet (@home = download: 1.00 Mbps / upload : 5.13 Mbps)

I confess that I am completely lost. Do you have any idea where it could come from?

In the meantime, here is the result of the lshw -C network order, don’t hesitate to ask me for the results of other orders, I will post them.

$ sudo lshw -C network *-network:1 description: Ethernet interface produit: Ethernet Connection (13) I219-LM fabricant: Intel Corporation identifiant matériel: 1f.6 information bus: pci@0000:00:1f.6 nom logique: enp0s31f6 version: 20 numéro de série: 38:14:28:0f:32:1a taille: 1Gbit/s capacité: 1Gbit/s bits: 32 bits horloge: 33MHz fonctionnalités: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=3.8.7-NAPI duplex=full firmware=0.8-4 ip=192.168.1.31 latency=0 link=yes multicast=yes port=twisted pair speed=1Gbit/s ressources: irq:147 mémoire:a2300000-a231ffff

Thank you in advance for your help ! 🙂

Update

Here are the results of the nestat -i and netstat -s commands (on my network at home) :

$ netstat -i Table d'interfaces noyau Iface MTU RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg enp0s31f 1500 29522 448 361 0 30261 0 0 0 BMRU lo 65536 4572 0 0 0 4572 0 0 0 LRU wlp0s20f 1500 7350 0 672 0 563 0 0 0 BMRU $ netstat -s Ip: Forwarding: 2 50727 total packets received 6 with invalid addresses 0 forwarded 0 incoming packets discarded 49394 incoming packets delivered 43118 requests sent out 20 outgoing packets dropped 542 dropped because of missing route Icmp: 67 ICMP messages received 0 input ICMP message failed Histogramme d'entrée ICMP destination unreachable: 67 762 ICMP messages sent 0 ICMP messages failed Histogramme de sortie ICMP destination unreachable: 762 IcmpMsg: InType3: 67 OutType3: 762 Tcp: 545 active connection openings 0 passive connection openings 4 failed connection attempts 5 connection resets received 3 connections established 29486 segments received 40360 segments sent out 861 segments retransmitted 1 bad segments received 290 resets sent Udp: 11379 packets received 1452 packets to unknown port received 0 packet receive errors 11028 packets sent 0 receive buffer errors 0 send buffer errors IgnoredMulti: 5760 UdpLite: TcpExt: 218 TCP sockets finished time wait in fast timer 164 delayed acks sent Quick ack mode was activated 36 times 7910 packet headers predicted 6247 acknowledgments not containing data payload received 10413 predicted acknowledgments TCPSackRecovery: 140 Detected reordering 1 times using SACK 6 congestion windows recovered without slow start after partial ack TCPLostRetransmit: 100 490 fast retransmits 48 retransmits in slow start TCPTimeouts: 95 TCPLossProbes: 300 TCPLossProbeRecovery: 30 TCPSackRecoveryFail: 7 TCPDSACKOldSent: 40 TCPDSACKOfoSent: 5 TCPDSACKRecv: 193 93 connections reset due to unexpected data 1 connections reset due to early user close 3 connections aborted due to timeout TCPDSACKIgnoredOld: 1 TCPDSACKIgnoredNoUndo: 109 TCPSackShifted: 790 TCPSackMerged: 1396 TCPSackShiftFallback: 320 TCPRcvCoalesce: 1208 TCPOFOQueue: 1950 TCPOFOMerge: 5 TCPChallengeACK: 1 TCPSYNChallenge: 1 TCPAutoCorking: 157 TCPSynRetrans: 43 TCPOrigDataSent: 27241 TCPHystartDelayDetect: 13 TCPHystartDelayCwnd: 421 TCPKeepAlive: 612 TCPDelivered: 27555 TCPAckCompressed: 187 TcpTimeoutRehash: 95 TcpDuplicateDataRehash: 3 IpExt: InMcastPkts: 2913 OutMcastPkts: 260 InBcastPkts: 5760 OutBcastPkts: 2 InOctets: 25001747 OutOctets: 37878931 InMcastOctets: 857652 OutMcastOctets: 17502 InBcastOctets: 5995183 OutBcastOctets: 108 InNoECTPkts: 52735 MPTcpExt:

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