Abstract: Methods and apparatus for enabling a provider to perform a tracing procedure to determine the existence forwarding problems within its network are disclosed. According to one aspect of the present invention, a method for detecting a forwarding problem within an autonomous system includes initiating a message from a source node. The message is sent to a message destination that is an external address relative to the autonomous system. The method also includes forwarding the message from the source node along a path to the external address which includes an intermediate node and a destination node. The message is received on the destination node through a first path segment of the path. Finally, the message is removed from the path at the destination node, and a response that indicates that the intermediate node does not have a forwarding problem is sent along the first path segment to the source node.

Abstract: Methods and apparatus for efficiently enabling routing states to be recovered after a failover or during a software upgrade in a system which supports graceful restart and stateful switchover are disclosed. According to one aspect of the present invention, a method for restarting a network device which has a plurality of routers and is in communication with a first peer being arranged to support graceful restart and a second peer includes performing a graceful restart with respect to the first peer. A peer transparent failover is performed with respect to the second peer. The graceful restart and the peer transparent failover are performed in response to a failure associated with the network device.

Abstract: Methods and apparatus for enabling a provider to perform a tracing procedure to determine the existence forwarding problems within its network are disclosed. According to one aspect of the present invention, a method for detecting a forwarding problem within an autonomous system includes initiating a message from a source node. The message is sent to a message destination that is an external address relative to the autonomous system. The method also includes forwarding the message from the source node along a path to the external address which includes an intermediate node and a destination node. The message is received on the destination node through a first path segment of the path. Finally, the message is removed from the path at the destination node, and a response that indicates that the intermediate node does not have a forwarding problem is sent along the first path segment to the source node.

Abstract: Methods and apparatus for enabling a provider to perform a tracing procedure to determine the existence forwarding problems within its network are disclosed. According to one aspect of the present invention, a method for detecting a forwarding problem within an autonomous system includes initiating a message from a source node. The message is sent to a message destination that is an external address relative to the autonomous system. The method also includes forwarding the message from the source node along a path to the external address which includes an intermediate node and a destination node. The message is received on the destination node through a first path segment of the path. Finally, the message is removed from the path at the destination node, and a response that indicates that the intermediate node does not have a forwarding problem is sent along the first path segment to the source node.

Abstract: Methods and apparatus for efficiently enabling routing states to be recovered after a failover or during a software upgrade in a system which supports graceful restart and stateful switchover are disclosed. According to one aspect of the present invention, a method for restarting a network device which has a plurality of routers and is in communication with a first peer being arranged to support graceful restart and a second peer includes performing a graceful restart with respect to the first peer. A peer transparent failover is performed with respect to the second peer. The graceful restart and the peer transparent failover are performed in response to a failure associated with the network device.

Abstract: Methods and apparatus for enabling a provider to perform a tracing procedure to determine the existence forwarding problems within its network are disclosed. According to one aspect of the present invention, a method for detecting a forwarding problem within an autonomous system includes initiating a message from a source node. The message is sent to a message destination that is an external address relative to the autonomous system. The method also includes forwarding the message from the source node along a path to the external address which includes an intermediate node and a destination node. The message is received on the destination node through a first path segment of the path. Finally, the message is removed from the path at the destination node, and a response that indicates that the intermediate node does not have a forwarding problem is sent along the first path segment to the source node.