Questions tagged [ethtool]
The ethtool tag has no usage guidance.
64
questions
1
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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 ...
- 13
0
votes
0
answers
38
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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, ...
- 214
0
votes
1
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71
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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 ...
0
votes
2
answers
219
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 ...
- 741
0
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3
answers
173
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?
- 103
2
votes
2
answers
1k
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:
...
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0
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54
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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 ...
- 111
0
votes
2
answers
610
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 ...
- 101
0
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1
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253
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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 ...
- 1
6
votes
1
answer
3k
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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 ...
- 499
0
votes
1
answer
6k
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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 ...
- 45
0
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0
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222
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?
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1
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311
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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 ...
- 121
0
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1
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2k
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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:
...
- 3
0
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1
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380
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 ...
- 3
1
vote
1
answer
888
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 ...
- 33
1
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1
answer
5k
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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-...
- 559
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 ...
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1
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1
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1k
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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?
- 11
2
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1
answer
27k
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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 ...
- 35
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0
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711
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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 ...
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9
votes
2
answers
777
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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 (...
- 1,693
3
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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
...
- 431
2
votes
2
answers
9k
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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 ...
- 608
0
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1
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143
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 / ...
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3
votes
0
answers
335
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]:...
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0
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653
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 ...
- 143
0
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1
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247
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
...
- 1,109
9
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2
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23k
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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: ...
- 174
1
vote
1
answer
18k
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
...
- 1,081
0
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5k
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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 ...
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-1
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1
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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
...
- 13
0
votes
1
answer
687
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.
...
- 187
1
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0
answers
975
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 ...
- 88
0
votes
0
answers
364
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?
- 639
2
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1
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14k
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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 ...
- 33
7
votes
1
answer
9k
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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 ...
- 173
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0
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7k
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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: ...
- 133
0
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1
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952
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:
...
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3
votes
4
answers
9k
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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 ...
- 791
11
votes
1
answer
11k
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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, ...
- 267
2
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2
answers
2k
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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 ...
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1
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720
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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 ...
- 757
1
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1
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7k
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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 ...
- 111
11
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2
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2k
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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. ...
- 32.8k
25
votes
8
answers
60k
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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 ...
- 571
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votes
1
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354
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, ...
- 41
10
votes
4
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27k
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Why is ethtool not showing me all the properties for a NIC?
CentOS 5.8 | VMWare ESX 5.1
When I run ethtool eth0 I see the following:
[root@foo ~]# ethtool eth0
Settings for eth0:
Current message level: 0x00000007 (7)
Link detected: yes
Is ...
- 11.9k
2
votes
1
answer
800
views
some nodes in a cluster has higher frame value in ifconfig
I am running a cluster consisting of 22 nodes.
(22 nodes under the same 1Gbps switch.)
I noticed some nodes in the cluster has higher "frame" value in
ifconfig like the following.
some nodes (higher ...
- 21
1
vote
1
answer
16k
views
changing network speed to 1000Mb/s
I am trying to change the server uplink from 100Mb/s to 1000Mb/s
ethtool eth0 output
# ethtool eth0
Settings for eth0:
Supported ports: [ TP MII ]
Supported link modes: ...
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