T

TCP port 179

The well-known port number used by BGP to establish a peering session with a neighbor.

tcpdump

A Unix packet monitoring utility used by the JUNOS software to view information about packets sent or received by the Routing Engine.

Terminal Access Controller Access Control System Plus (TACACS+)

Authentication method for validating users who attempt to access the router.

terminating action

An action in a routing policy or firewall filter that halts the logical software processing of the policy or filter.

terms

Used in a routing policy or firewall filter to segment the policy or filter into smaller match and action pairs.

through

JUNOS software routing policy match type representing all routes that fall between the two supplied prefixes in the route filter.

Timeout timer

Used in a distance-vector protocol to ensure the current route is still usable for forwarding traffic. The JUNOS software uses a default value of 120 seconds.

token-bucket algorithm

Used in a rate-policing application to enforce an average bandwidth while allowing bursts of traffic up to a configured maximum value.

totally stubby area

An OSPF area type that prevents Type 3, 4, and 5 LSAs from entering the non-backbone area.

traffic engineering

Process of selecting the paths chosen by data traffic in order to balance the traffic load on the various links, routers, and switches in the network. (Definition from http:// www.ietf.org/internet-drafts/draft-ietf-mpls-framework-04.txt.) See also Multi- protocol Label Switching (MPLS).

transient interfaces

Interfaces that can be moved from one location in the router to another. All customer-facing interfaces are considered transient in nature.

transit area

In OSPF, an area used to pass traffic from one adjacent area to the backbone or to another area if the backbone is more than two hops away from an area.

transit router

In MPLS, any intermediate router in the LSP between the ingress router and the egress router.

Transmission Control Protocol (TCP)

Works in conjunction with Internet Protocol (IP) to send data over the Internet. Divides a message into packets and tracks the packets from the point of origin.

transport mode

An IPSec mode of operation in which the data payload is encrypted but the original IP header is left untouched. The IP addresses of the source or destination can be modified if the packet is intercepted. Because of its construction, transport mode can be used only when the communication endpoint and cryptographic endpoint are the same. VPN gateways that provide encryption and decryption services for protected hosts cannot use transport mode for protected VPN communications. See also tunnel mode.

triggered updates

Used in a distance-vector protocol to reduce the time for the network to converge. When a router has a topology change, it immediately sends the information to its neighbors instead of waiting for a timer to expire.

Triple-DES

A 168-bit encryption algorithm that encrypts data blocks with three different keys in succession, thus achieving a higher level of encryption. Triple-DES is one of the strongest encryption algorithms available for use in VPNs.

Tspec Object

RSVP message object that contains information such as the bandwidth request of the LSP as well as the minimum and maximum packets supported.

tunnel

Private, secure path through an otherwise public network.

tunnel mode

An IPSec mode of operation in which the entire IP packet, including the header, is encrypted and authenticated and a new VPN header is added, protecting the entire original packet. This mode can be used by both VPN clients and VPN gateways, and protects communications that come from or go to non-IPSec systems. See also transport mode.

Tunnel PIC

A physical interface card that allows the router to perform the encapsulation and decapsulation of IP datagrams. The Tunnel PIC supports IP-IP, GRE, and PIM register encapsulation and decapsulation. When the Tunnel PIC is installed, the router can be a PIM rendezvous point (RP) or a PIM first-hop router for a source that is directly connected to the router.

type of service (ToS)

The method of handling traffic using information extracted from the fields in the ToS byte to differentiate packet flows.




JNCIP. Juniper Networks Certified Internet Professional Study Guide Exam CERT-JNCIP-M
JNCIP: Juniper Networks Certified Internet Professional Study Guide
ISBN: 0782140734
EAN: 2147483647
Year: 2003
Pages: 132

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