Juniper NETWORK AND SECURITY MANAGER 2010.3, Administration Manual

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Authentication Header
(AH)
See ESP/AH.
Authentication Server
Objects
An authentication server provides authentication for NSM administrators and RAS users on
your network. Use authentication servers objects to set a default authentication server for the
global domain and each subdomain, or access an external RADIUS or SecurID system to
provide authentication.
Autonomous System
(AS)
An AS is a set of routers set off from the rest of the network and governed by a single technical
administration. This router group uses an interior gateway protocol (IGP) or several IGPs and
common metrics to route packets within the group. The group also uses an exterior gateway
protocol (EGP) to route packets to other ASs. Each AS has a routing plan that indicates what
destinations are reachable through it. This plan is called the Network Layer Reachability
Information (NLRI) object. BGP routers generate and receive NLRI updates periodically.
Autonomous System
Boundary Router
A router that connects an AS running one routing protocol to another AS running a different
protocol.
Autonomous System
Path
A list of all the autonomous systems that a router update has traveled through in the current
transmission.
B
Bastion Host A bastion host is a hardened system that is configured with the minimal software to support
a single network service.
BGP Neighbor (Also known as a BGP Peer). BGP is a the Border Gateway Patrol dynamic routing protocol. A
BGP neighbor is another device on the network that is running BGP. There are two types of
BGP neighbors: internal neighbors, which are in the same autonomous system, and external
neighbors, which are in different autonomous systems. A reliable connection is required between
neighbors and is achieved by creating a TCP connection between the two. The handshake
that occurs between the two prospect neighbors evolves through a series of phases or states
before a true connection can be made. See Connection States.
Border Gateway
Protocol (BGP)
An inter-autonomous system routing protocol. BGP routers and autonomous systems exchange
routing information for the Internet.
Broadcast Network A network that connects many routers together and can send, or broadcast, a single physical
message to all the attached routers. Pairs of routers on a broadcast network are assumed to
be able to communicate with each other. Ethernet is an example of a broadcast network. On
broadcast networks, the OSPF router dynamically detects its neighbor routers by sending Hello
packets to the multicast address 224.0.0.5. For broadcast networks, the Hello protocol elects
a Designated Router and Backup Designated Router for the network.
Copyright © 2010, Juniper Networks, Inc. 826
Network and Security Manager Administration Guide