BGP Attribute analysis

[Aneek]

Pls, find the attached doc for reference. Pls, help me solve the questions given below.

Q.1. Both router R1 and R2 are sending same traffic to R. However, I want to bias only one of them (Either R1 or R2) and receive traffic from them. From the perspective of R in AS1234 what BGP attribute must be used. 

Q.2. Both router R1 and R2 are sending same traffic to R. However, I being a service provider what my router R1 to send traffic to R. From service providers perspective What BGP attribute must be used?

[Georg Pauwen · Accepted solution]

Hello,

Q1: To influence the inbound traffic path, you can use and/or MED, AS-PATH, BGP communities in the updates sent to the ISPs. Longest prefix-matching with BGP conditional route injection is another option.

Q2: Not sure what you are asking. For outbound traffic manipulation, you can use local preference or weight... 

[Aneek]

Thank you. This was what I was thinking. 

I have one more question. 

The traffic flow is always opposite to route flow. Why?

[Georg Pauwen]

Hello,

to be honest, I am not sure what that means...

Is that written in some documentation somewhere, do you have a link ?

[Joseph W. Doherty]

If you mean what I think you mean, yes, although keep in mind there can be multiple "route flows" (i.e. different peers), and especially with BGP, data flow might only take one egress path (even for ECMP).