On 4/8/20 2:42 PM, Drew Weaver wrote:
Hello,
I’ve noticed over the past couple of weeks that some hosts on a network I manage appear to be trying to reach hosts in this network 100.114.128.0/24
It’s an IANA reserved block but I’m really not sure what it’s used for. I just notice it keeps coming up but it doesn’t have a route.
Has anyone else been seeing this?
This is part of the RFC6598 space for carrier-NAT deployments. If you're seeing traffic inbound to your network to those addresses, someone's presumably got a default toward you and a hole in their internal routing table. If you're seeing traffic outbound toward those addresses, some of your customers have somehow picked up a configuration expecting some sort of service there. Inbound traffic toward your network from or to those addresses is effectively a bogon. Outbound traffic from/to those addresses means you have a misconfiguration somewhere (presumably unintentional and perhaps some poorly behaved automatic config on a CPE). -- Brandon Martin