{"id":1126,"date":"2025-03-13T09:40:33","date_gmt":"2025-03-13T09:40:33","guid":{"rendered":"https:\/\/thomas.w-p.me.uk\/blog\/?p=1126"},"modified":"2025-03-13T09:40:33","modified_gmt":"2025-03-13T09:40:33","slug":"ethernet-speed","status":"publish","type":"post","link":"https:\/\/thomas.w-p.me.uk\/blog\/2025\/03\/ethernet-speed\/","title":{"rendered":"Ethernet Speed"},"content":{"rendered":"\n

https:\/\/serverfault.com\/questions\/207474\/how-do-i-verify-the-speed-of-my-nic<\/a><\/p>\n\n\n\n

Thanks to serverfault I found how to check link speed between two debian machines – iperf3<\/p>\n\n\n\n

You can see the expected max speed using ethtool:<\/p>\n\n\n\n

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# assuming eth0 is the interface we care about<\/span><\/span>\n~<\/span>$ sudo ethtool eth0 <\/span>|<\/span> <\/span>grep<\/span> <\/span>Speed<\/span><\/span>\n        <\/span>Speed:<\/span> <\/span>10000<\/span>Mb\/s<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
To see real-time speeds install iperf3, then run one machine as server and one as client:<\/p>\n\n\n\n
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# on both machines<\/span><\/span>\napt<\/span> <\/span>install<\/span> <\/span>iperf3<\/span> <\/span>-y<\/span><\/span>\n# say no to the install at startup - this is just for occasional testing<\/span><\/span>\n<\/span>\n# on machine A, which is 192.168.1.3<\/span><\/span>\niperf3<\/span> <\/span>-s<\/span><\/span>\n<\/span>\n# on machine B - reach out to machine A's IP address<\/span><\/span>\niperf3<\/span> <\/span>-c<\/span> <\/span>192.168<\/span>.1.3<\/span><\/span>\n<\/span><\/code><\/pre><\/div>\n\n\n\n
I got 250 Mb\/s whilst doing a backup on the cabling I installed myself 25 years ago (before gigabit was a thing)  to a USB ethernet 25m away from the switch, so I will take that.<\/p>\n","protected":false},"excerpt":{"rendered":"
https:\/\/serverfault.com\/questions\/207474\/how-do-i-verify-the-speed-of-my-nic Thanks to serverfault I found how to check link speed between two debian machines – iperf3 You can see the expected max speed using ethtool: To see real-time speeds install iperf3, then run one machine as server and one as client: I got 250 Mb\/s whilst doing a backup on the cabling I installed … Continue reading Ethernet Speed<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[123,27],"tags":[],"class_list":["post-1126","post","type-post","status-publish","format-standard","hentry","category-debian","category-geekiness"],"_links":{"self":[{"href":"https:\/\/thomas.w-p.me.uk\/blog\/wp-json\/wp\/v2\/posts\/1126","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/thomas.w-p.me.uk\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/thomas.w-p.me.uk\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/thomas.w-p.me.uk\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/thomas.w-p.me.uk\/blog\/wp-json\/wp\/v2\/comments?post=1126"}],"version-history":[{"count":1,"href":"https:\/\/thomas.w-p.me.uk\/blog\/wp-json\/wp\/v2\/posts\/1126\/revisions"}],"predecessor-version":[{"id":1127,"href":"https:\/\/thomas.w-p.me.uk\/blog\/wp-json\/wp\/v2\/posts\/1126\/revisions\/1127"}],"wp:attachment":[{"href":"https:\/\/thomas.w-p.me.uk\/blog\/wp-json\/wp\/v2\/media?parent=1126"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/thomas.w-p.me.uk\/blog\/wp-json\/wp\/v2\/categories?post=1126"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/thomas.w-p.me.uk\/blog\/wp-json\/wp\/v2\/tags?post=1126"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}