On Wednesday, 28 November 2018, SDSC’s Security Team will implement a network border block that prevents hosts running the RPC Portmapper service (port 111/udp) on SDSC’s networks from becoming unwilling participants in distributed denial-of-service (DDoS) attacks. This change will not affect port 111/tcp.
Please contact Winston Armstrong (SDSC CISO) or Scott Sakai (SDSC Security Analyst) for more information, or if your host(s) are adversely affected by this block.
For more about DDoS attacks:
https://en.wikipedia.org/wiki/Denial-of-service_attack