Stephen Satchell <list@xxxxxxxxxxxx> writes: > I'm concerned that Centos 8 is using a pre-release version of > nftables. I just did a system update, and found this as current: > > /etc/redhat-release: CentOS Linux release 8.1.1911 (Core) > $ nft -v: nftables v0.9.0 (Fearless Fosdick) You might want to look for other installed packages < 1.0.0: rpm -qa --qf '%{name} %{version}-%{release}\n' | sort --sort=version --key=2 It's... not uncommon. :-) On my laptop, fully 20% of packages are below version 1. > To ensure BGP-38 compliance upstream, I'll use the routing table > extension that I have developed for NetworkManager, that I posted > earlier, that null-routes all reserved netblocks. (I'm not planning > to incorporate the BOGON enhancement as suggested by others.) I think you mean BCP-38: https://tools.ietf.org/html/bcp38 > The following will appear in my /etc/sysctl.conf file, which turns on > source filtering and logs martians. > > net.ipv6.conf.all.disable_ipv6 = 1 > net.ipv4.conf.all.rp_filter = 1 > net.ipv4.conf.all.log_martians = 1 > > net.ipv6.conf.default.disable_ipv6 = 1 > net.ipv4.conf.default.rp_filter = 1 > net.ipv4.conf.default.log_martians = 1 > > Yes, this means that I'm blocking all ipv6 for now. I will reconsider > as the 1.0 or later release version makes it to the CentOS 8 > distribution. CentOS runs systemd, so rp_filter=1 (or =2 since v240) should be on by default: https://github.com/systemd/systemd/blob/master/sysctl.d/50-default.conf