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Router Security Configuration Guide
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Version 1.0g
DNS
Domain Name System – hierarchical naming scheme used
for host and network names on most IP networks, including
the Internet. DNS is also the name for the protocol used to
transmit and relay domain name information. DNS is
standardized in RFCs 1034 and 1035.
DoS
Denial of Service – this abbreviation is often used for
network attacks that prevent a network component from
providing its operational functions, or that crash it.
DDoS
Distributed Denial of Service – This abbreviation is used for
DoS attacks that use mult iple (usually hundreds or more)
coordinated network data sources to attack a single victim.
EIGRP
Extended Interior Gateway Routing Protocol – A Cisco
proprietary routing protocol, not commonly used (see also
OSPF).
Enable mode
A slang expression for a privileged EXEC session on a
Cisco router, derived from the command used to request
privileged EXEC mode: enable.
ESP
Encapulated Security Payload – a part of IPSec, the packet
format and protocol for IP confidentiality services (see also
IPSec, IKE, AH)
FTP
File Transfer Protocol – widely-used TCP-based file transfer
and file management protocol. Typically, FTP control
messages are passed on TCP port 21. FTP is standardized in
RFC 959.
ICMP
Internet Control Message Protocol – a support protocol used
along with IP for control and status message. ICMP is a
network layer protocol that provides error messages and
management capabilities in IP networks. ICMP is
standardized in RFC 792.
IETF
Internet Engineering Task Force – the technical and
consultative body that defines standards for the Internet.
IETF standards are published by RFC number, the list of
current standards is RFC 2400.
IKE
Internet Key Exchange – the standard security negotiation
and key management protocol used with IPSec. IKE is
standardized in RFC 2409.
IOS
Internet Operating System – Cisco’s name for the modular
software system that runs on their routers and some other
network devices.