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Asymmetrical Routing, TCP Packets Out of Order: Lab


I've seen a problem at work which I'd like to simulate, but am wondering how best to go about the build.

The situation: a streaming media application handles tcp packets out of order by discarding and requesting retransmit. This causes major slow down. The packets are arriving out of order because there is more than one path to take between the endpoints.

Attaching a packet tracer example (intend to use gns3).

MapMapIt seems to me that the simplist working example of the situation will be three routers, traffic between the endpoints able to traverse either just one link, or having to traverse two. It is simulating the 'or' part that has me stumped.

Perhaps one way to cause the oscillating traffic would be to bring a route up and down every second on one of the endpoint routers?

2 Replies 2

MHM Cisco World
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VIP Mentor

are you router connect to ISP ?

Joseph W. Doherty
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Hall of Fame Master

Unlikely changing a route would have the effect you're after.

Set up two paths, with different physical bandwidths, route cost the same, then ECMP either process switching or CEF packet-by-packet.

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