Slowing network speed

Doug Hardie bc979 at lafn.org
Sat Jul 25 00:18:29 UTC 2020


> On 24 July 2020, at 16:59, Patrick Mahan <plmahan at gmail.com> wrote:
> 
> ping is not a good indicate of network speed since most ping packets are
> small.  Network performance depends on many issue.  Most notably the total
> amount of data being transmitted, what TCP congestion algorithm is in
> effect, how much kernel buffer space, etc.
> 
> You can increase the size of the ping packet using the '-s' option, or use
> the ping sweep options (-G <maxsize> -g <minsize>) etc.  See ping(8).
> 
> Interface packet status can be retrieved using 'netstat -I <interface>'
> Other stats can be pulled using 'netstat -4 -x' (for IPv4 packet buffer
> using, delayed acks, retransmissions, etc).  See netstat(8).
> 
> Traceroute is only semi-useful as it relies on ICMP error response which
> are throttled by many routers.
> 
> iperf requires that you have a remote port you can talk to to send and
> receive traffic.


I have found that mtr (in the ports) is a good diagnostic tool for networks.  It combines traceroute and ping into one function that works a lot faster than traceroute.  I use the mtr-nox11 port as it is purely a command line tool.  It gives you a good idea where in the network bottlenecks are occurring.  

-- Doug



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