Juniper J2300 User Manual page 287

Term Definition
handshake Process of exchanging signaling information between two communications devices to establish
the method and transmission speed of a connection.
hello packet In OSPF, a packet sent periodically by a router to first establish and then maintain network
adjacency, and to discover neighbor routers.
hold time Maximum number of seconds allowed to elapse between the time a BGP system receives
successive keepalive or update messages from a peer.
hop Trip a data packet takes from one router to another in the network. The number of routers
through which a packet passes to get from its source to its destination is known as the hop
count. In general, the best route is the one with the shortest hop count.
Intermediate Link-state, interior gateway routing protocol for IP networks that also uses the shortest-path-first
System-to-Intermediate (SPF) algorithm to determine routes.
System (IS-IS)
interior gateway protocol Protocol that exchanges routing information within autonomous systems (ASs). IS-IS, OSPF,
(IGP) and RIP are IGPs. Compare exterior gateway protocol (EGP) .
Internal BGP (IBGP) BGP configuration in which sessions are established between routers in the same autonomous
systems (ASs).
internal peer In BGP, a peer that resides in the same autonomous system (AS) as the Services Router.
keepalive message Periodic message sent by one BGP peer to another to verify that the session between them is
still active.
latency Delay.
link-state advertisement Messages that announce the presence of OSPF-enabled interfaces to adjacent OSPF interfaces
(LSA) (neighbors). The exchange of LSAs establishes bidirectional connectivity between neighbors.
local preference Optional BGP path attribute carried in internal BGP update packets that indicates the degree of
preference for an external route.
mesh Network topology in which devices are organized in a manageable, segmented manner with
many, often redundant, interconnections between network nodes. See also full mesh .
metric Numerical value that determines how quickly a packet can reach its destination. See also cost .
multiple exit Optional BGP path attribute consisting of a metric value that is used to determine the exit point
discriminator (MED) to a destination when all other factors in determining the exit point are equal.
neighbor Adjacent router interface. A node can directly route packets to its neighbors only. See also peer .
network Series of nodes interconnected by communication paths.
network diameter Maximum hop count in a network.
network topology Arrangement of nodes and connections in a network.
node Connection point that operates as a redistribution point or an end point in a network,
recognizing data transmissions and either forwarding or processing them.
notification message Message sent between BGP peers to inform the receiving peer that the sending peer is
terminating the session because an error occurred, and explaining the error.
not-so-stubby area (NSSA) In OSPF, a type of stub area in which external route advertisements can be flooded.
open message
Message sent between BGP peers to establish communication.
Open Shortest Path First A link-state interior gateway protocol (IGP) that makes routing decisions based on the
protocol (OSPF) shortest-path-first (SPF) algorithm (also referred to as the Dijkstra algorithm).
origin Value assigned to a BGP route to indicate whether the first router to advertise the route learned
it from an external, internal, or unknown source.
Routing Overview
257
Routing Terms