Abstract: A technique efficiently determines acceptable link-based loop free alternates (LFAS) in a computer network. According to the novel technique, a protecting network device configured to protect a link (“protected link”) distinguishes other network devices (e.g., of the same domain as the protecting network device) as either network edge devices (i.e., an end point for external network traffic) or network core devices (i.e., not an end point for external network traffic). The protecting network device may then determine whether a neighboring network device loops toward a network edge device. If not, the protecting network device may determine that the neighboring network device is an acceptable LFA (e.g., for external network traffic). Notably, traffic directed to core devices may still loop, however, this traffic is generally internal (e.g., signaling) traffic, and may not be subject to the same operational constraints (e.g., protection) as external traffic.

Abstract: A technique efficiently avoids transient routing disturbances in link state routing protocols with fragmented link state packets (LSPs) in a computer network. According to the novel technique, a link state router (LSR) specifies which of two or more links are to be advertised in each of two or more corresponding LSP fragments. The LSR advertises the states of the specified links in the corresponding LSP fragments to one or more other LSRs. In other words, each link of the LSR is assigned to a particular LSP fragment, and the state of the link is always to be advertised in that particular LSP fragment (i.e., no fragment wrapping). Upon receiving the LSP fragments, the other LSRs may update the correct link states based on the individual LSP fragments, i.e., without transient routing disturbances caused by fragment wrapping.

Abstract: A technique optimizes routing of application data streams on an Internet Protocol (IP) backbone in a computer network. According to the novel technique, a client router learns of server states (e.g., number of pending requests, etc.) of a plurality of application servers and also determines metrics of intermediate links between the application servers and the client router (intermediate link metrics), e.g., particularly link metrics in a direction from the application servers to the client router. Upon receiving an application request from an application client (“client request”), the client router determines to which of the application servers the client request is to be sent based on the server states and intermediate link metrics, and sends the client request accordingly.