💾 Archived View for rawtext.club › ~sloum › geminilist › 006395.gmi captured on 2021-12-05 at 23:47:19. Gemini links have been rewritten to link to archived content
⬅️ Previous capture (2021-11-30)
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Stephane Bortzmeyer stephane at sources.org
Tue Apr 20 11:33:01 BST 2021
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On Tue, Apr 20, 2021 at 10:18:03AM +0000, Sgaith <Sgiath at pm.me> wrote a message of 46 lines which said:
I am not too familiar with low level networking so I am looking for
more information here. Specifically I would like to test scenario
where client request comes in multiple packets over very slow
connection. Is there some automated test which can do that for me?
Or how could I test it manually (on Linux)?
On Linux, you can use the "tc" program to tell the kernel to dropand/or delay packets. For instance (DON'T TYPE IT BEFORE READING IT!)
tc qdisc add dev tap0 root netem delay 150ms loss 50%
Will add 150 ms of delay to all packets going through the networkinterface tap0 and in addition will drop (more or less) half of them.
% ping -c 10 gemini.circumlunar.space PING gemini.circumlunar.space(2604:180:f3::185 (2604:180:f3::185)) 56 data bytes64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=1 ttl=54 time=78.6 ms64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=2 ttl=54 time=78.7 ms64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=3 ttl=54 time=78.4 ms64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=4 ttl=54 time=78.6 ms64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=5 ttl=54 time=78.6 ms64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=6 ttl=54 time=78.5 ms64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=7 ttl=54 time=79.7 ms64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=8 ttl=54 time=78.6 ms64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=9 ttl=54 time=78.4 ms64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=10 ttl=54 time=82.8 ms
--- gemini.circumlunar.space ping statistics ---10 packets transmitted, 10 received, 0% packet loss, time 23msrtt min/avg/max/mdev = 78.380/79.089/82.831/1.323 ms
% sudo tc qdisc add dev eth1 root netem delay 150ms loss 50%
% ping -c 10 gemini.circumlunar.space PING gemini.circumlunar.space(2604:180:f3::185 (2604:180:f3::185)) 56 data bytes64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=1 ttl=54 time=229 ms64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=2 ttl=54 time=230 ms64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=3 ttl=54 time=229 ms64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=4 ttl=54 time=233 ms64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=7 ttl=54 time=229 ms64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=8 ttl=54 time=230 ms64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=9 ttl=54 time=229 ms64 bytes from 2604:180:f3::185 (2604:180:f3::185): icmp_seq=10 ttl=54 time=229 ms
--- gemini.circumlunar.space ping statistics ---10 packets transmitted, 8 received, 20% packet loss, time 71msrtt min/avg/max/mdev = 228.666/229.638/232.723/1.252 ms