Often on FreeBSD servers you can see the pfsync0 pseudo-interface up:

[root@bsd ~]# ifconfig
...(skipped)
pfsync0: flags=0<> mtu 2020 
 syncpeer: 224.0.0.240 maxupd: 128

Unless you are running a pf firewall with redundancy, you won't need this, moreover on CPanel/WHM enabled servers, Cpanel sometimes tries to assign this multicast ip to a domain/customer.

You can safely disable it by adding:

pfsync_enable="NO"

to /etc/rc.conf

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