Network diagnosis utilities

[davidlv]

I know about "namebench", which tests for good DNS name servers, but are there any other network diagnosis utilities available? One associate has a problem with slow downloads even from fast servers, Apple etc.
I have tried setting the MTU to 1453, rather than the default 1500 in the Hardware tab of the Network/Advanced system preferences pane, with no apparent change.
Any suggestions?

 

[Evren Carven]

I usually diagnose the network error by following way.

1. Choose Apple menu > System Preferences, then click Network.
2. Click “Assist me,” click Diagnostics, then follow the onscreen instructions.

 

[Significant1]

Are they using any security software like Antivirus?

See this thread, where it turned out to be Sophos Antivirus:
https://forums.macrumors.com/threads/gigabit-ethernet-troubles.1903341/#post-21634997

 

[robgendreau]

IPNetMonitorX.