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In order to test our deployment I want to simulate certain network events like connection losses, timeout, limited bandwidths etc.

I already googled for this but haven't found something that really suited my needs. ipfw seems to be what I need but I can't seem to find an ipfw package for Ubuntu. Also I'd like to know whether there are alternatives or even better tools for my task.

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You can use iptables and tc. – Mircea Vutcovici Feb 17 '11 at 15:05
up vote 1 down vote accepted

You can simulate those things with firewall.

Userland tool to modify firewall rules is called iptables

for example if you want to simulate 5 seconds of connection loss you can do this

iptables -I INPUT -p tcp -s --dpor $port -j DROP ; sleep 5; iptables -D INPUT -p tcp -s --dpor $port -j DROP ;

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Thanks! Pretty cool! Is there something equally elegant to simulate high latencies? I'd like to say "port 1234 has a latency of XXXXms". – Jan Deinhard Feb 18 '11 at 7:50

iptables is great, but some tools are sharper when dealing with this kind of problems.

And also wanem, not a standalone app but more a customized router distro.

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From the sister site Stack Overflow: Simulate delayed and dropped packets on Linux

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