P$23.$ Consider the example in Figure $8\mathrm{.}28.$ Suppose Trudy is a woman$-$in$-$themiddle, who can insert datagrams into the stream of datagrams going from R$1$ and R$2.$ As part of a replay attack, Trudy sends a duplicate copy of one of the datagrams sent from R$1$ to R$2.$ Will R$2$ decrypt the duplicate datagram and forward it into the branch$-$office network? If not, describe in detail how R$2$ detects the duplicate datagram.

$(30$ points$)$

Figure $8\mathrm{.}28-$ Security association $(SA)$ from $R1$ to $R2$