>>> iperf 2.0.13 Downloading
--2019-01-23 22:13:25--  http://downloads.sourceforge.net/project/iperf2/iperf-2.0.13.tar.gz
Resolving downloads.sourceforge.net (downloads.sourceforge.net)... 216.105.38.13
Connecting to downloads.sourceforge.net (downloads.sourceforge.net)|216.105.38.13|:80... connected.
HTTP request sent, awaiting response... 302 Found
Location: https://netcologne.dl.sourceforge.net/project/iperf2/iperf-2.0.13.tar.gz [following]
--2019-01-23 22:13:26--  https://netcologne.dl.sourceforge.net/project/iperf2/iperf-2.0.13.tar.gz
Resolving netcologne.dl.sourceforge.net (netcologne.dl.sourceforge.net)... 78.35.24.46, 2001:4dd0:1234:6::5f
Connecting to netcologne.dl.sourceforge.net (netcologne.dl.sourceforge.net)|78.35.24.46|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 326148 (319K) [application/x-gzip]
Saving to: '/home/buildroot/buildroot-test/instance-0/output/build/.iperf-2.0.13.tar.gz.E7MM6f/output'

     0K .......... .......... .......... .......... .......... 15% 1.18M 0s
    50K .......... .......... .......... .......... .......... 31% 1.25M 0s
   100K .......... .......... .......... .......... .......... 47% 9.96M 0s
   150K .......... .......... .......... .......... .......... 62% 9.14M 0s
   200K .......... .......... .......... .......... .......... 78% 1.48M 0s
   250K .......... .......... .......... .......... .......... 94% 9.79M 0s
   300K .......... ........                                   100% 10.9M=0.1s

2019-01-23 22:13:27 (2.38 MB/s) - '/home/buildroot/buildroot-test/instance-0/output/build/.iperf-2.0.13.tar.gz.E7MM6f/output' saved [326148/326148]

ERROR: iperf-2.0.13.tar.gz has wrong sha1 hash:
ERROR: expected: 3eb21c329af811af53a2c816e1ed26b3dd2c259f
ERROR: got     : 0c7625c61087b9e6866421abb8bb533658b40a8d
ERROR: Incomplete download, or man-in-the-middle (MITM) attack
--2019-01-23 22:13:27--  http://sources.buildroot.net/iperf/iperf-2.0.13.tar.gz
Resolving sources.buildroot.net (sources.buildroot.net)... 104.25.211.19, 104.25.210.19, 2606:4700:20::6819:d213, ...
Connecting to sources.buildroot.net (sources.buildroot.net)|104.25.211.19|:80... connected.
HTTP request sent, awaiting response... 404 Not Found
2019-01-23 22:13:28 ERROR 404: Not Found.

--2019-01-23 22:13:28--  http://sources.buildroot.net/iperf-2.0.13.tar.gz
Resolving sources.buildroot.net (sources.buildroot.net)... 104.25.211.19, 104.25.210.19, 2606:4700:20::6819:d213, ...
Connecting to sources.buildroot.net (sources.buildroot.net)|104.25.211.19|:80... connected.
HTTP request sent, awaiting response... 404 Not Found
2019-01-23 22:13:29 ERROR 404: Not Found.

make: *** [/home/buildroot/buildroot-test/instance-0/output/build/iperf-2.0.13/.stamp_downloaded] Error 1
make: Leaving directory `/home/buildroot/buildroot-test/instance-0/buildroot'