Henning–Löwenstein–Rautenbach domination-packing conjecture for subcubic graphs

Let $G$ be a connected subcubic graph, let $\rho(G)$ denote its packing number, and let $b3(G)$ denote its domination number. The graphs $H_1$, $H_2$, and $H_3$ are the three specified exceptional graphs.

Henning–Löwenstein–Rautenbach conjecture. Every connected subcubic graph $G$ except the three graphs $H_1$, $H_2$, and $H_3$ satisfies

$$\gamma(G) \le 2\rho(G).$$

This conjecture concerns the relationship between domination and packing in subcubic graphs. The source attributes it to Henning, Löwenstein, and Rautenbach; its resolution status is not specified in the supplied text.