USC/ISI is renumbering both its IPv4 and IPv6 addresses for on 2023-11-27. Our new IPv4 address will be and our new IPv6 address will be 2801:1b8:10::b. USC/ISI will continue to support root service over our current IPv4 and IPv6 addresses for at least one year (until 2024-11-27) in order to provide a stable transition period while new root hints files are distributed in software and operating system packages.

We are renumbering to increase the resilience of the Root Servers System by further diversifying the number of Regional Internet Registries (RIRs) that have allocated IP addresses to Root Server Operators. Our addresses will be the first in the Root Server System to have been allocated by LACNIC and our routes will be verifiable through LACNIC’s Resource Public Key Infrastructure (RPKI) Trust Anchor Location (TAL). We thank LACNIC for helping make this renumbering possible, and ARIN for supporting our prior addressing assignments.

Update on 2023-05-30: LACNIC posted a separate announcement about this renumbering.