Shortest paths¶
Consider the network below.
![\tikzstyle{arrow} = [thick,->,>=stealth]
\tikzset{router/.style = {rectangle, draw, text centered, minimum height=2em}, }
\tikzset{host/.style = {circle, draw, text centered, minimum height=2em}, }
\tikzset{ftable/.style={rectangle, dashed, draw} }
\node[router] (R1) { R1 };
\node[router,right=of R1] (R2) {R2};
\node[router,below=of R1] (R3) {R3};
\node[router,below=of R2] (R4) {R4};
\path[draw,thick]
(R1) edge node [midway,fill=white] {\em{3}} (R2)
(R3) edge node [midway,fill=white] {\em{3}} (R2)
(R1) edge node [midway, fill=white] {\em{2}} (R3)
(R4) edge (R3)
(R2) edge (R4);](_images/tikz-18dc8059e5da8b4ca40ae889f4c8a7dab9a13fc9.png)
Given the link weights shown in the figure above, which of the following affirmations about the shortest paths in this network are correct ?
The shortest path from R4 to R1 is via R3.
The shortest path from R2 to R3 is via R4.
The shortest path from R1 to R2 is via R3.
The shortest path from R3 to R2 is the direct link.
The shortest path from R3 to R2 is via R4.
The shortest path from R1 to R4 is via R3.