Questions[test](server)

I need to test network throughput of a server to/from itself (it's a lonnnng story!).

I love Iperf and use it across the network, but, I just can't figure out how to bind it to a single interface and only listen via that.

From the documentation, I would assume that this would work: iperf -B eth0 -s to bind one instance to eth0, then in another session: iperf -B eth1 -c ip.of.eth.1.

This doesn't work at all, and actually fails. If I use the ip instead of interface, it does work, but, throughput is at 29Gb/s - so, unless there is some magic going on where by I have a super server with a 30Gb/s card, I am guessing that I am not even touching the network and this is just going locally.

Can anyone help me here, or know of a better test/tool?

I have a webserver with a current connection of 100Mbit and my provider offers an upgrade to 1Gbit. I understand that this refers to throughput but the larger the packets, the faster they can be transmitted as well, so I would expect a slight decrease in response time (e.g. ping). Did anybody ever benchmarked this?

Example (100mbit to 100mbit server) with 30 byte load:

> ping server -i0.05 -c200 -s30
[...]
200 packets transmitted, 200 received, 0% packet loss, time 9948ms
rtt min/avg/max/mdev = 0.093/0.164/0.960/0.093 ms

Example (100mbit to 100mbit server) with 300 byte load (which is below MTU):

> ping server -i0.05 -c200 -s300
[...]
200 packets transmitted, 200 received, 0% packet loss, time 10037ms
rtt min/avg/max/mdev = 0.235/0.395/0.841/0.078 ms

So from 30 to 300 the avg. latency increaces from 0.164 to 0.395 - I would expect this to be a slower increase for a 1gibt to 1gbit connection. I even would expect 100mbit to 1gbit to be faster, if the connection is through a switch which first waits until it received the whole packet.

Update: Please read the comments to the answers carefully! The connection is not saturated, and I don't think that this speed increase will matter for humans for one request, but it is about many requests which add up (Redis, Database, etc.).

Regarding answer from @LatinSuD:

> ping server -i0.05 -c200 -s1400
200 packets transmitted, 200 received, 0% packet loss, time 9958ms
rtt min/avg/max/mdev = 0.662/0.866/1.557/0.110 ms

I was just poking around in /usr/bin and I found an ELF binary file called [. /usr/bin/[. I have never heard of this file and my first thought was that it was a clever way of hiding a program, possibly a trojan. However it's present on all my CentOS servers and seems to have no manual entry. I can hazard a guess as to what it is but I was looking for a more authoritative answer...

I'm trying to figure out the differences(pros/cons) between two routing protocols approach and I would be great-full for any help, advice and explanation. As far I can say that it seems like distance vector is more static and more local based routing, since it doesn't know the network state whereas link state is more aware of current states therefore it seems more natural to use it over distance-vector, but I have a feeling like I'm missing something. And I would be glad to here about more aspects and different issues I have to consider while choosing one of them.

Our development server at work is taking a dump on us. So at this point, we're repurposing some other servers we have in our server room for this purpose.

My boss wants me to test the servers before I even try installing anything on them. How do we to about this?