This command shows the kernel modules that are currently loaded.
# lsmod
Module Size Used by
vboxdrv 55088 0
autofs4 20421 2
ipt_MASQUERADE 6721 1
iptable_nat 9669 1
nf_nat 18669 2 ipt_MASQUERADE,iptable_nat
nf_conntrack_ipv4 11717 2 iptable_nat
nf_conntrack 51977 4 ipt_MASQUERADE,iptable_nat,nf_nat,nf_conntrack_ipv4
....