module issue?

[Dave Stevens]

I want to configure nat and I get this:

sudo iptables -t nat -A  POSTROUTING -o eth0 -j MASQUERADE -v
iptables v1.6.0: can't initialize iptables table `nat': Table does not
exist (do you need to insmod?) Perhaps iptables or your kernel needs to
be upgraded.

uname -r
4.9.80+

and 

ls -l /lib/modules
total 8
drwxr-xr-x 3 root root 4096 May 24 03:32 4.14.34+
drwxr-xr-x 3 root root 4096 May 24 03:32 4.14.34-v7+

I think I understand that /lib/modules will need to have an entry for
4.9.80+ but doesn't. 
I've run sudo apt upgrade so I don't think that's a problem .But I
don't see how to proceed. Anyone?


Dave