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ethool -m text output incomplete, but complete as hex

We're struggling with reading Laser rx/tx levels from a 10G SFP" in a Supermicro server. ethtool -m (or --modinfo or --dump-module-eeprom) is supposed to deliver this info, and it does work... ...
Marc 'netztier' Luethi's user avatar
0 votes
0 answers
59 views

Missing Detailed Output in ethtool -T Command on Nvidia Jetson Orin AGX Dev Kit

I am currently using the Nvidia Jetson Orin AGX dev kit with a Basler GigE interface card and two GigE Cameras connected to port 0 and 1 (eth0 and eth1) I am trying to setup PTP with ptp4l and phc2sys ...
Nailtha's user avatar
3 votes
1 answer
697 views

List of supported devices and drivers for ethtool --cable-test

I want to use ethtool to test a network cable with ethtool --cable-test and ethtool --cable-test-tdr. I tried to do this (as root) on my machine (internal network adapter), two USB-to-Ethernet ...
TNT2k's user avatar
  • 131
1 vote
2 answers
229 views

Is it possible for a NIC to send data when only the eth TX+ and TX- (eth) lines are connected?

I have a high security network that needs to send data to a less secure network. The connection must be physically unable to send data from the low security network to the high security network. I ...
Marked's user avatar
  • 13
0 votes
0 answers
270 views

When executing command ethtool -S ethX instead of expected statistics following message is displayed: "no stats available"

It ethtool command only fails on ethtool -S ethX. If I run the command ethtool -i ethX it shows the expected data. This is on RHEL8. It's a known issue apparently, since Redhat itself has a solution, ...
Shōgun8's user avatar
  • 212
0 votes
1 answer
378 views

Trying to set wake-on-lan persistently on linux fails

This is my box: Linux mediacenter 5.15.122-1-MANJARO #1 SMP PREEMPT Tue Jul 25 07:09:46 UTC 2023 x86_64 GNU/Linux I am trying to follow https://wiki.archlinux.org/title/Wake-on-LAN But I am failing to ...
phetherer's user avatar
0 votes
2 answers
874 views

Alma 9 Unable to make the interface DOWN at boot

OS: Alma-9.2 I am trying to disable an interface (ens224) at boot using the nmcli tool. I tried using the option nmcli connection modify ens224 connection.autoconnect no,nmcli connection down id ...
Vishnu's user avatar
  • 751
0 votes
3 answers
534 views

No info found about `ethtool -T` output?

Nowhere I can find such info, to interpret the following number: PTP Hardware Clock: 1 Most documentation I can find (e.g. from RedHat it shows 0). What does it mean?
jaques-sam's user avatar
3 votes
2 answers
4k views

What does "sudo ethtool -K <interface> tx-checksum-ip-generic off" do exactly? Should I be worried about turning it off?

Recently upgraded to Debian 11 bullseye, and our Docker swarm nodes had trouble talking to each other, and started dropping some connections. After much Google-ing, we stumbled on these threads: ...
Keith Palmer Jr.'s user avatar
0 votes
0 answers
78 views

Why does connectivity differ for straight and crossover cabling towards 1Gbit MDI-X capable switch (from Linux OS)?

There's no constraint with directly connecting a Realtek 1000/100/10Mbit transceiver towards a common router. There was no connection ('Could not activate connection: Connection 'Name of Lan ...
beyondtime's user avatar
0 votes
2 answers
847 views

Unable to ping other devices in the network through ethernet port on a custom board

I am on a embedded development platform and trying to bring up the ethernet and do a ping test. As of now, I have the ethernet up after the linux boot, but I am unable to ping other systems. My ...
user2532296's user avatar
0 votes
1 answer
421 views

Is there any load when reading EEPROM inside SFP module?

I am trying to measure the optical receving/transmitting levels with ethtool on the server. It was confirmed that ethtool reads information from EEPROM inside the SFP module. When a read operation to ...
beginner's user avatar
7 votes
1 answer
4k views

Why NIC ring parameters are not pre-set at their Hardware max capabilities?

Check the NIC ring buffer: # ethtool -g eth0 Ring parameters for eth0: Pre-set maximums: RX: 4096 RX Mini: 0 RX Jumbo: 0 TX: 4096 Current hardware settings: RX: 256 RX ...
CrazyRabbit's user avatar
0 votes
1 answer
8k views

Linux Link Speed Advertise

As far as I know, the following command would set the speed and duplex advertised by auto-negotiation. ethtool -s eth0 advertise 0x020 where 0x020 indicates 1000baseT Full according to the following ...
aschkant's user avatar
0 votes
0 answers
418 views

What if command (ethtool) to flash physical ports on NIC does not work? How can I identify which of the live ports are flapping?

I have 2 live ports and one of which has network flapping issue. ethtool -p runs but does not flash my ports. What else can I do without pulling the wrong fiber?
peacht's user avatar
  • 1
1 vote
1 answer
430 views

Should ethtool on one machine show different speed to the other machine?

I have two connected computers. On host A, ethtool shows a speed of 100Mb/s, but host B that is connected to it shows 10Mb/s. Why is this the case? On host B, the link partner advertised link mode is ...
placid chat's user avatar
1 vote
1 answer
3k views

Can not disable autoneg via ethtool

I want to disable the auto-negotiation feature of NIC, I run the following command $sudo ethtool -s ens1f0 speed 10000 duplex full autoneg off Then I check if it takes effect via ethtool ens1f0: ...
HypoGump's user avatar
0 votes
1 answer
464 views

How to direct flows to specific vf queue?

SR-IOV allows us to create a VF from PF, now I want to direct some flows to VF via Flow Director. Here is ethtool help message action N Specifies the Rx queue to send packets to, or some other ...
HypoGump's user avatar
1 vote
1 answer
1k views

Wrong link speed; what happens if manually set speed using ethtool fails?

I've got a remote xen server and I noticed that the speed link in autoneg is 100 Full Duplex; all my network is 1000 Full Duplex; do you know any reason for this? Ethtool mentions on both my server ...
SYS64738's user avatar
1 vote
1 answer
7k views

how to verify status of TCP Segmentation Offloading

we do the following on linux rhel machines ethtool -K ifcfg-478476 tso off now lets say that we want to verify the settings how to do the check with ethtool or other cli? we try ethtool -k ifcfg-...
King David's user avatar
2 votes
1 answer
4k views

Where to find list of possible arguments for ethtool -K?

When I want to disable/enable interface features with the ethtool -K command, how can I list all available options? When I run ethtool -k I see a list of options, but I don't know the equivalent ...
snowsnoot's user avatar
1 vote
1 answer
2k views

When using ethtool -S what is the difference between rx_packets and rx_pkts_nic?

rx_packets are much larger than rx_pkts_nic. Why is this the case? Is there a doc somewhere with explanation of all the NIC stat fields?
jjdiaz's user avatar
  • 11
2 votes
1 answer
33k views

Collecting SFP+ attributes in Linux

I need to collect hw component inventory from physical systems running RHEL (6 and 7) and its derivatives. I need to collect the SFP+ attributes along with the rest of the components. I know I can ...
Lubos A.'s user avatar
2 votes
0 answers
854 views

Meaning of rx_fcs_errors

On my server I do see RX frame errors in ifconfig: eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 ether d0:50:99:30:f6:81 txqueuelen 1000 (Ethernet) RX packets ...
Stefan's user avatar
  • 31
9 votes
2 answers
790 views

nic: Something Wicked happened! ffff

I'm configuring a GNU/Linux Router with Debian Stretch (9.7) and before rebooting the server, all traffic from one interface to another was going ok, but after that, I received a message like this (...
ivanleoncz's user avatar
  • 1,761
3 votes
1 answer
5k views

What does rx_csum_offload_errors mean?

I see too many rx_csum_offload_errors on ethtool output and it constantly increases. What is the reason of these errors and how can I fix it? # ethtool -S enp12s0f0 | grep error rx_errors: 0 ...
ibrahim's user avatar
  • 431
2 votes
2 answers
10k views

Changing network interface speed with ethtool is not working

Im using lenevo M5 server which have Gbps ethernet cards, but strangely when i read cat /sys/class/net/eth3/speed it show 100 similarly when using ethtool it show 100Mbps only.The output of dmesg and ...
sherpaurgen's user avatar
0 votes
1 answer
152 views

What data is not available for tcpdump unlike interface statistics tools?

I'm analizing the logs on specific interface and wondering why this command during small load-test: tcpdump -i enp21s0f0 -s0 -w /tmp/dump2.cap` catched only 75 MB, when ethtool -S enp21s0f0 / ...
John's user avatar
  • 31
3 votes
0 answers
359 views

What do the numbers in square brackets of ethtool output mean?

I'm looking at NIC statistics and can't find any info about these numbers: [0],[1]..[7] like here: [root@machine-1 ~]# ethtool -S enp21s0f0 NIC statistics: [0]: rx_bytes: 23048043995115 [0]:...
John's user avatar
  • 31
0 votes
0 answers
690 views

Same ethernet cards, same firmware, same drivers ... different Advertising Mode

I have a strange issue. Having same cards, same drivers and same updated version of ethtool on 2 different OS, (XenServer7.* and centOS7.3). if I run on centOS ethtool on the card I get: Supported ...
Max Cuttins's user avatar
0 votes
1 answer
269 views

transfer rate faster than the NIC suggests

i followed this thread to get the information on reading NIC speeds. How do I verify the speed of my NIC? i am using ethtool to verify the speed of my NIC as discussed the thread. :~ # ethtool eth0 ...
lauc.exon.nod's user avatar
9 votes
2 answers
26k views

What does the ring parameter in ethtool -g output signify?

For instance, if I run ethtool -g eth0 on my system, I get the following output: Ring parameters for eth0: Pre-set maximums: RX: 4096 RX Mini: 0 RX Jumbo: 0 TX: ...
tejus's user avatar
  • 184
1 vote
1 answer
19k views

how to change the auto-negotiation to yes in linux servers

when I run the ethtool command on eth0 ( on VM machine redhat version 6.7 ) I see Supports auto-negotiation: No can we change this to - auto-negotiation: yes ? , is it configurable? ethtool eth0 ...
dandan's user avatar
  • 1,081
0 votes
0 answers
5k views

Cannot get current device settings: Operation not supported ethtool CentOS 7

Received an error "Cannot get current device settings: Operation not supported ethtool" while changing network speed using ethtool command on centos, # ethtool -s eth0 autoneg off speed 100 duplex ...
lakshmikandan's user avatar
-1 votes
1 answer
8k views

ethtool error for limiting interface speed

i am limiting my bandwidth using ethtool and i used this command: sudo ethtool -s eth2 speed 500 But i got error message: Cannot advertise speed 500 i tried adding duplex half ...
yasmink's user avatar
  • 13
0 votes
1 answer
724 views

nic configuration on a linux virtual machine (rackspace)

I am trying to check my nic speed and duplex setting on a vm I have at rackspace. It is centos 6.4. When I run: # ethtool eth0 Settings for eth0: Link detected: yes This is all I get back. ...
Joelio's user avatar
  • 187
1 vote
0 answers
1k views

lxc / docker wake on lan?

Has anyone successfully implemented "wake on LAN" functionality in a linux container? In my setup each client has his own container for a vpn, but I only want the container to "boot up" when the ...
Miles R's user avatar
  • 88
0 votes
0 answers
365 views

Alternative ways to track dropped packets and report output

Instead of tailing /var/log/messages or doing a continuous ping is there a way with ifconfig or ethtool to track dropped packets, collisions, or tx/rx errors in real time?
user53029's user avatar
  • 649
2 votes
1 answer
15k views

Unable to set eth0 autoneg off speed 1000 duplex full : invalid argument

I use Ubuntu server for my things,but when i config speed 1000 and duplex full the error occur. I've tried the answers from here,does not work, the command i used is ethtool -s eth0 speed 100 duplex ...
amrino's user avatar
  • 33
7 votes
2 answers
9k views

meaning of rx_queue_*_csum_err and rx_fifo_errors

I am trying to debug some networking issue with one server. I monitor this machine with multiple monitors and I see that at times ping error rate jumps to 5/10% I am running on ubuntu and I see that ...
Tommaso Barbugli's user avatar
2 votes
0 answers
7k views

Cannot set 1G speed on 10G nic using ethtool

I have a linux server with 10G fibre nics: xyz@xyz48:~$ sudo ethtool p1p1 Settings for p1p1: Supported ports: [ FIBRE ] Supported link modes: 10000baseT/Full Supported pause frame use: ...
Akshya11235's user avatar
0 votes
1 answer
992 views

How to change the setting for a network device reported by ethtool, specifically Speed, on VM?

This is related to these two questions, although they don't answer my question. The machines are RHEL6. 1.ethtool not showing all the properties 2.changing network speed to 1000Mb/s Output on VM: ...
Ramadheer Singh's user avatar
3 votes
4 answers
10k views

Disable TCP checksum offloading on KVM virtual network

I have a virtual network for connecting KVM guests with the host. I need to disable TCP checksum offloading on this network. The ethtool works fine but I want to disable it permanently and I could ...
jackhab's user avatar
  • 801
12 votes
1 answer
12k views

ethtool says that eth0 uses MII but twisted pair is used

ethtool says that "Supported ports: [ TP MII ]" and "Port: MII". I guess that TP means twisted pair and Media Independent Interface. However physically I see that network card uses twisted pair cable, ...
scdmb's user avatar
  • 277
2 votes
2 answers
2k views

How to detect ethernet uplink speed on CentOS 6 OpenVZ VPS

I recently purchased a VPS which was advertised as a 100Mbps uplink but the promotion promised a free upgrade to a 1Gbps uplink. I'm trying to find out if I received the upgrade with various methods ...
SSpoke's user avatar
  • 161
0 votes
1 answer
742 views

Extremely slow network and half duplex

I am having an extremely slow network netperf -H 11.x.x.21 TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 11.x.x.21 (11.x.x.19) port 0 AF_INET Recv Send Send Socket Socket Message ...
Kevin Parker's user avatar
1 vote
1 answer
7k views

Can't set NIC speed to 10Gbps using ethtool

We're using IBM Blade Center HS-22 servers with Broadcom NetXtreme II 10Gbps NICs to a Nortel 10Gbps switch. With one of the chassis the NICs can establish a 10G rate with the command "ethtool eth2 ...
MartyE's user avatar
  • 111
11 votes
2 answers
2k views

packet queue performance discrepencies with BIND nameserver

Background: I've inherited a high volume caching nameserver environment (Redhat Enterprise Linux 5.8, IBM System x3550) that has inconsistent ring buffer settings: 1020 for eth0 and 255 for eth1. ...
Andrew B's user avatar
  • 33.2k
26 votes
8 answers
64k views

How to persist ethtool settings through reboot

I would like to turn off tcp segmentation offload on a CentOS5 server. Using ethtool the command is ethtool -K eth0 tso off However, this setting only persists for this session. How can I make it ...
Gus E's user avatar
  • 581
3 votes
1 answer
361 views

Why is my bandwidth averaging 3 kbps on a 10 mbps device?

I have a server with a 100 mbps port and connection that I rate limited to 10 mbps/full duplex because I am only paying for a 10 mbps connection and there are steep overage charges. Ever since then, ...
compucuke's user avatar