Useful Diagnostics

IPERF3

[Iperf3 https://github.com/esnet/iperf] - Useful for testing site to site throughput

Example
To configure one end as a server

[root@PDC2MGT002 ~]# iperf3 -s
-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------

To configure one end as a client, and to begin throughput testing.

[root@PDC1MGT002 ~]# iperf3 -c pdc2mgt002 -i1
Connecting to host pdc2mgt002, port 5201
[  4] local 10.80.139.17 port 59378 connected to 10.160.139.17 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec  97.3 MBytes   816 Mbits/sec   51   1.22 MBytes       
[  4]   1.00-2.00   sec  93.8 MBytes   786 Mbits/sec    0   1.30 MBytes       
[  4]   2.00-3.00   sec  92.5 MBytes   776 Mbits/sec    0   1.36 MBytes       
[  4]   3.00-4.00   sec  66.2 MBytes   556 Mbits/sec    0   1.40 MBytes       
[  4]   4.00-5.00   sec  83.8 MBytes   703 Mbits/sec    0   1.43 MBytes       
[  4]   5.00-6.00   sec   106 MBytes   891 Mbits/sec    0   1.44 MBytes       
[  4]   6.00-7.00   sec   105 MBytes   881 Mbits/sec    0   1.45 MBytes       
[  4]   7.00-8.00   sec   108 MBytes   902 Mbits/sec    0   1.45 MBytes       
[  4]   8.00-9.00   sec   106 MBytes   891 Mbits/sec    0   1.45 MBytes       
[  4]   9.00-10.00  sec   109 MBytes   912 Mbits/sec    0   1.45 MBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec   967 MBytes   811 Mbits/sec   51             sender
[  4]   0.00-10.00  sec   965 MBytes   809 Mbits/sec                  receiver
#
iperf Done.
[root@PDC1MGT002 ~]#

Scamper

[Scamper http://www.wand.net.nz/scamper/] - Usefule for testing site to site latency and other stuff like per hop MTU reporting

Example
To show traceroute and MTU of each hop to host 10.129.1.254

[root@PDC2MGT002 scamper-cvs-20110421]# scamper -c "trace -M" -i 10.129.1.254
traceroute from 10.160.139.17 to 10.129.1.254
 1  10.160.139.253  0.491 ms [mtu: 1500]
 2  10.161.230.251  0.564 ms [mtu: 1500]
 3  100.65.0.2  3.831 ms [mtu: 1422]
 4  10.221.1.253  3.789 ms [mtu: 1422]

ESNET

http://fasterdata.es.net/performance-testing/network-troubleshooting-tools/ - A useful site with reference data to some of these tools.

MTR

mtr combines the functionality of the 'traceroute' and 'ping' programs in a single network diagnostic tool.

As mtr starts, it investigates the network connection between the host mtr runs on and a user-specified destination host. After it determines the address of each network hop between the machines, it sends a sequence ICMP ECHO requests to each one to determine the quality of the link to each machine. As it does this, it prints running statistics about each machine.