>Смотрю дамп сетевого интерфейса, там наблюдается большое кол-во следующих пакетов:
>
>21:47:08.444873 arp who-has 10.30.1.110 tell 10.30.122.133
>21:47:08.457736 arp who-has 10.30.132.206 tell 10.30.40.235
>21:47:08.457755 arp who-has 10.30.40.19 tell 10.30.40.235
>21:47:08.457890 arp who-has 10.30.121.80 tell 10.30.40.235
>21:47:08.567133 arp who-has 10.30.40.231 tell 10.30.40.235
>21:47:08.567153 arp who-has 10.30.40.242 tell 10.30.40.235
>21:47:08.567298 arp who-has 10.30.155.28 tell 10.30.40.235
>21:47:08.567322 arp who-has 10.30.40.197 tell 10.30.40.235
>21:47:08.567429 arp who-has 10.30.214.37 tell 10.30.40.235
>21:47:08.567449 arp who-has 10.30.21.66 tell 10.30.40.235
>21:47:08.567466 arp who-has 10.30.156.15 tell 10.30.40.235
>21:47:08.661328 arp who-has 10.30.40.68 tell 10.30.40.235
>21:47:08.661905 arp who-has 10.30.134.24 tell 10.30.20.74
>21:47:08.669071 arp who-has 10.30.1.138 tell 10.30.1.15
>21:47:08.676531 arp who-has 10.30.40.52 tell 10.30.40.235
>21:47:08.676551 arp who-has 10.30.156.235 tell 10.30.40.235
>21:47:08.692912 arp who-has 10.30.55.38 tell 10.30.20.87
>21:47:08.731084 arp who-has 10.30.1.200 tell 10.30.1.15
>21:47:08.745115 arp who-has 10.30.20.29 tell 10.30.20.74
>21:47:08.769985 arp who-has 10.30.20.1 tell 10.30.20.74
>21:47:08.785927 arp who-has 10.30.111.37 tell 10.30.40.235
>21:47:08.785947 arp who-has 10.30.40.134 tell 10.30.40.235
>21:47:08.840622 arp who-has 10.30.1.136 tell 10.30.1.15
>21:47:08.846321 arp who-has 10.30.80.245 tell 10.30.20.74
>21:47:08.846475 arp who-has 10.30.34.60 tell 10.30.20.74
>21:47:08.863878 arp who-has 10.30.20.152 tell 10.30.20.74
>21:47:08.872208 arp who-has 10.30.1.169 tell 10.30.1.15
>21:47:08.872656 arp who-has 10.30.1.220 tell 10.30.1.15
>21:47:08.874996 arp who-has 10.30.1.219 tell 10.30.1.15
>
>Почему так много и нормально ли это?

потому что сетка большая и, скорее всего, юзается маска 255.255.0.0