Introducing latency for testing?

[Mike Lyon]

So I want to mimic some latency in a test network for DB replication.
I am wondering what other's have used for this? Obviously, the best
way to would be to actually have one box across the US or across the
globe to actually test against but what if you don't have that? Are
there any GPL software router solutions that would allow you to tweak
the latency in between the two test boxes?

Thanks in advance.

-Mike

[C. Tate Baumrucker]

setup a linux box between the systems with netem (included in most
distros).
http://www.linux-foundation.org/en/Net:Netem
with it, you can introduce latency, loss, jitter, etc.
tate

Post by Mike Lyon
So I want to mimic some latency in a test network for DB replication.
I am wondering what other's have used for this? Obviously, the best
way to would be to actually have one box across the US or across the
globe to actually test against but what if you don't have that? Are
there any GPL software router solutions that would allow you to tweak
the latency in between the two test boxes?
Thanks in advance.
-Mike
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http://mailman.nanog.org/mailman/listinfo/nanog

[Deepak Jain]

Or a FreeBSD box with DUMMYNET (runs through IPFW). You can do all of
that stuff.

Post by C. Tate Baumrucker
setup a linux box between the systems with netem (included in most
distros).
http://www.linux-foundation.org/en/Net:Netem
with it, you can introduce latency, loss, jitter, etc.
tate

Post by Mike Lyon
So I want to mimic some latency in a test network for DB replication.
I am wondering what other's have used for this? Obviously, the best
way to would be to actually have one box across the US or across the
globe to actually test against but what if you don't have that? Are
there any GPL software router solutions that would allow you to tweak
the latency in between the two test boxes?
Thanks in advance.
-Mike
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http://mailman.nanog.org/mailman/listinfo/nanog

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http://mailman.nanog.org/mailman/listinfo/nanog

[Mike Lyon]

Thank you all for the wonderful responses!

Cheers,
Mike

Or a FreeBSD box with DUMMYNET (runs through IPFW). You can do all of that
stuff.

Post by C. Tate Baumrucker
setup a linux box between the systems with netem (included in most

distros). http://www.linux-foundation.org/en/Net:Netem

Post by C. Tate Baumrucker
with it, you can introduce latency, loss, jitter, etc.
tate

Post by Mike Lyon
So I want to mimic some latency in a test network for DB replication.
I am wondering what other's have used for this? Obviously, the best
way to would be to actually have one box across the US or across the
globe to actually test against but what if you don't have that? Are
there any GPL software router solutions that would allow you to tweak
the latency in between the two test boxes?
Thanks in advance.
-Mike
_______________________________________________
NANOG mailing list
http://mailman.nanog.org/mailman/listinfo/nanog

_______________________________________________
NANOG mailing list
http://mailman.nanog.org/mailman/listinfo/nanog

[Geoff Lisk]

NISTnet at http://snad.ncsl.nist.gov/nistnet/

Also, there is a commercial (reasonably priced) product called network
nightmare. (http://networknightmare.net/)

Cisco also has an .iso that they'll give to customers that's a NISTnet
livecd.

-Geoff

Post by Mike Lyon
So I want to mimic some latency in a test network for DB replication.
I am wondering what other's have used for this? Obviously, the best
way to would be to actually have one box across the US or across the
globe to actually test against but what if you don't have that? Are
there any GPL software router solutions that would allow you to tweak
the latency in between the two test boxes?
Thanks in advance.
-Mike
_______________________________________________
NANOG mailing list
http://mailman.nanog.org/mailman/listinfo/nanog

[Stephane Bortzmeyer]

On Fri, May 02, 2008 at 01:12:52PM -0700,

Post by Mike Lyon
So I want to mimic some latency in a test network for DB replication.
I am wondering what other's have used for this? Obviously, the best
way to would be to actually have one box across the US or across the
globe to actually test against but what if you don't have that? Are
there any GPL software router solutions that would allow you to tweak
the latency in between the two test boxes?

I use and like FreeBSD's dummynet:

http://info.iet.unipi.it/~luigi/ip_dummynet/

Highly recommended.

[Joel Jaeggli]

The freebsd dummynet driver is all about latency simulation...

http://www.scalabledesign.com/articles/dummynet.html

linux has a netem which can do the same thing

http://www.linux-foundation.org/en/Net:Netem

joelja

Post by Mike Lyon
So I want to mimic some latency in a test network for DB replication.
I am wondering what other's have used for this? Obviously, the best
way to would be to actually have one box across the US or across the
globe to actually test against but what if you don't have that? Are
there any GPL software router solutions that would allow you to tweak
the latency in between the two test boxes?
Thanks in advance.
-Mike
_______________________________________________
NANOG mailing list
http://mailman.nanog.org/mailman/listinfo/nanog

[Phil Regnauld]

Post by Joel Jaeggli
The freebsd dummynet driver is all about latency simulation...
http://www.scalabledesign.com/articles/dummynet.html
linux has a netem which can do the same thing
http://www.linux-foundation.org/en/Net:Netem

dummynet is significantly easier to set up, especially for
doing things like random packet reordering / packet loss (using the
'prob' rule of ipfw + delay property with pipes).

ipfw pipe 42 config bw 1024Kbit/s delay 6ms
ipfw pipe 666 config bw 64Kbit/s delay 350ms

ipfw add 10 prob 0.05 deny ip from 1.2.3.4 to any
ipfw add 10 prob 0.8 pipe 666 ip from A to B
ipfw add 10 prob 0.5 pipe 42 ip from A to B

... and it runs.

[c***@thewybles.com]

Netem is a very cool tool! Thanks for mentioning it.


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