LISP DDT root installed at CSUC's facilities

LISP DDT root
16-07-2014

LISP DDT root (Locator/ID Separation Protocol Delegated Database Tree) has been implemented at CSUC's facilities in collaboration with Cisco and the Universitat Politècnica de Catalunya (UPC). The objective is to experiment with this new network infrastructure and internet protocol.

Ip addresses, both IPv4 and IPv6, are currently part of the same space allocation, where identities of devices are not distinguished from how these devices are connected to the net. Together with the so-called multihoming (or the use of more than one service provider), and some computer network practices for deaggregating IP prefixes, such a fact has increased internet routing tables to levels that are difficult to assume for many routers.

LISP is a network architecture and set of protocols that implements a new semantic for IP addressing. It is based on the separation of the current IP addresses in two namespace: the relatively static Endpoint Identifiers (EID), used end-to-end for communications, and Routing Locators (RLOC), which are more dynamic and used for routing and forwarding through the internet infrastructure. To make it clear, it could be said that LISP separates the 'where' (RLOC) from the 'who' (EID). LISP follows a network-based map-and-encapsulate scheme, so no changes to hosts are needed, everything happens in the network.

LISP DDT is a distributed and hierarchic database which embodies the delegation of authority to provide mappings from LISP Endpoint Identifiers (EIDs) to Routing Locators (RLOCs), in a quite similar way in how DNS servers work. It provides delegation information to map-resolvers, which use the information to locate EID-to-RLOC mappings. A map resolver which needs to locate a given mapping will follow a path through the tree-structured database, contacting, one after another, the DDT nodes along that path until it reaches the leaf DDT node authoritative for the mapping it is seeking. LISP DDT root nodes, such as the one installed at CSUC, are on the top of the hierarchy, as DNS root servers are as well.