Re: traffic delay insertion

From: Petr Lapukhov (petr@internetworkexpert.com)
Date: Wed Jan 24 2007 - 12:21:59 ART

I would still recommend to use FreeBSD/Linux based tools, like dummynet, as
it
was previously mentioned.

While funny, the "repetitive VRFs" scheme has serious problem: you could not

predictively control the introduced delay/loss parameters. Worst of it,
delay
could vary with router/interface load in non-linear manner.

After all it makes little sense to utilize poorly-controlled device for
modeling
in lab environment, since the resulting data will have low statistical
value.

You may also opt to look at software modeling tools like NS2, though they
have more scientific, rather than practical application :)

HTH 

-- 
Petr Lapukhov, CCIE #16379 (R&S/Security)
petr@internetworkexpert.com

Internetwork Expert, Inc.
http://www.InternetworkExpert.com

2007/1/24, Alex Ouraev <ualexv@gmail.com>:
>
> I have used the following method to get close to production LD delay:
>
> ip vrf 1
>   rd 0:1
>
> ip vrf 2
>   rd 0:2
>
> int tun 1
>   ip vrf forwarding 1
>   ip add 10.0.0.1 255.255.255.0
>   tunnel source 5.0.0.1
>   tunnel destination 5.0.0.2
>   ip mtu 1500
>
> int tun 2
>   ip vrf forwarding 2
>   ip add 10.0.0.2 255.255.255.0
>   tunnel source 5.0.0.2
>   tunnel destination 5.0.0.1
>   ip mtu 1500
>
> int loop 0
>   ip add 5.0.0.1 255.255.255.0
>   ip add 5.0.0.2 255.255.255.0 secondary
>
> Note:
>
>   1. int loop 0 ins not included into any vrf
>   2. default ip mtu for a tunnel = 1490. ip mtu 1500 fixes that
>
> Routing within:
>
> router eigrp 100
>   address-famuly ipv4 vrf 1
>   network 10.0.0.0
>   no auto-summary
>   autonomous-system 100
>
>   address-famuly ipv4 vrf 2
>   network 10.0.0.0
>   no auto-summary
>   autonomous-system 100
>
> etc.
>
> Debug:
>
> sh ip route vrf 1|2
> ping vrf 1|2
> sh ip eigrp vrf 1|2 neigh
> etc...
>
> HTH
>
> Alex
>
>
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> Pat
> Sent: Tuesday, January 23, 2007 11:26 PM
> To: Group Study
> Subject: traffic delay insertion
>
> Hi GS,
> I don't believe this function exists at all, but just to double-check,
> in case I missed something simple.
>
> Background: Delay insertion was desired in a lab environment to
> simulate production network delay form City A to City B.
>
> Thanks!
> Pat
> #16228
>
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