Routing updating with PointToPoint links and BGP (Quagga)

[Jonay Rodríguez Báez]

Hello,

I have a strange behaviour when I try to congest a scenario with PointToPoint links and BGP. As you can see in the attached image, my current scenario is the following:

- Three ASN's:

ASN 1 In the network 192.168.1.0

ASN 2 In the network 99.0.0.0

ASN 3 In the network 88.0.0.0

- Real PC's in three ASN's. Every node used as entry point on any ASN uses FDNetDevice to connect to a real network interface.

- The communication between the different ASN is using the BGP protocol. The lines colored in blue are the BGP links.

For test this scenario I'm trying:

- Send information from "RealPC 1"(ASN1) to PC "RealPC 4" (ASN2).

- Congest the route between ASN1 and ASN2.

- Force to update the routing tables to get a new path between ASN1 and ASN2.

All works fine until I try to force congestion in the BGP links. I have the following time line:

- At 100 seconds of starting the emulation, I congest the BGP link 10.1.1.0 applying a big delay to this link:

/ChannelList/0/$ns3::PointToPointChannel/Delay

- After (approximately) 250 seconds, the routing tables are updated with the new routes. Network 10.1.1.0 is removed in the new table as gateway. You can see this, in the line 74, in the attached emulation.routes file.

- At (approximately) 450 seconds, the routing tables are updated again but in this case, the routes to network 99.0.0.0 (ASN2) are removed from the nodes 0 and 2.

- Until the end, the routes will not be updated again. The ASN1 and ASN2 there will not able to communicate again.

To congest a link, I'm using different ways but always with the same result. Researching the PCAP files, the routing tables and the stdout files provided by Quagga I cannot find anything because when routes disappear nothings in being saved in PCAP files. I am not able to understand what is the problem. Anybody know any way to force the routing updating or maybe the problem is other thing?

I'm using DCE (version 1.9) and FDNetDevices(NS3 version 2.6).

Thanks in advance