Do I have access to iptables and other kernel modules on the Linux v-server?
Yes, our Linux Virtual Server contains all the usual kernel modules. Since iptables are run as root, you need to have appropriate administration rights for the server and can edit the appropriate modules (iptables / netfilter, tun / tap, etc.). The iptables are installed on most Linux systems as /usr/sbin/iptables. In the man pages you will find further documentation about the iptables, if they are installed.
Since the kernel 3.13 released in January 2014, there is a new, additional packet filter with nftables, which can be used as an alternative to iptables.
A small hint: Before setting up the iptables or a firewall, be clear about what you want to achieve. What should be blocked and what should be allowed. The security of the server is not increasing just by starting a firewall. Or by a poor configuration you get less security or you are blocking yourself.
You can also compile your own kernel modules or use a self-compiled kernel.