netstat -i always shows Idrop 48665

I made some minor changes to my nginx server using a Linux VPS running FreeBSD 10.3 with TLS, ciphers and then file caches. Except for the file caching, I had done these changes before without issue. I went away for the weekend and, when I came back, netstat -i showed Idrop as being 48665. The web sites on this server don't exhibit any problems that I can see.

I reverted all my changes back to their original but I still see the same value for Idrop and it never changes from day to day or throughout the day. All the other values change accordingly.

Name    Mtu Network       Address              Ipkts Ierrs Idrop    Opkts Oerrs  Coll
em0    1500 <Link#1>      xx:xx:3c:cd:7e:c7 725249751     0 48665  2735394     0     0
em0       - xxxx::xxx:3cf xxxx::xxx:3cff:fe        0     -     -        3     -     -
em0       - xxx.xxx.21.23 website2.co      268     -     -        0     -     -
em0       - xxx.xxx.21.0  website3.or     1128     -     -     1221     -     -
lo0   16384 <Link#2>                            2227     0     0     2227     0     0
lo0       - ::1           ::1                      0     -     -        0     -     -
lo0       - xxxx::1%lo0   xxxx::1%lo0              0     -     -        0     -     -
lo0       - your-net      localhost                0     -     -        0     -     -

Notice that there are two web sites shown, both on different IPs. However, there are two other web sites on this same server with the same IP as website2 but they aren't listed. What's with that?

I have to say that, while I love networking, I never get to deal with it and this server has been around for several years, running without issues, so I'm at a loss as to how to troubleshoot this.