If you use the 'ping' command in a terminal, how frequently (if ever) do the network paths to/from the destination differ?
What could cause such paths to differ?
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For such a general question, the answer is equally general: "they differ quite often".
Asymmetric routing is easy to see on a small scale with a circle of routers each with clockwise default route:
A -> R1 -> R2 ^ v R4 <- R3 <- B
Arrows show default routes. Ping from A to B will go A->R1->R2->R3->B and the return will be B->R3->R4->R1->A.
Multiple paths are easy to see with routers which have some variety of load balancing:
/- R2 -\ A -> R1 -+ +- R4 <- B \- R3 -/
If R1 and R4 route to either R2 or R3 depending on the load at a given instant, one packet will go A->R1->R2->R4->B and the next might go A->R1->R3->R4->B.