Glossary of Interconnection and Networking Terms
A comprehensive reference of key terms used in Internet interconnection, BGP routing, and IX operations.
A
AS (Autonomous System) A collection of IP networks and routers under the control of one organization that presents a common routing policy to the Internet. Each AS is identified by a unique ASN.
ASN (Autonomous System Number) A unique number assigned to an Autonomous System for use in BGP routing. Example: Google is AS15169.
AMS-IX Amsterdam Internet Exchange, one of the world's largest Internet Exchange Points, founded in 1994.
B
BGP (Border Gateway Protocol) The routing protocol that enables data to flow between different autonomous systems across the Internet. Often called the "postal system" of the Internet.
Bogon An IP address that is invalid, unallocated, or reserved and should not appear in Internet routing tables.
C
CIDR (Classless Inter-Domain Routing) A method for allocating IP addresses and routing that replaced the old "classful" system, allowing more efficient use of IPv4 address space.
CDN (Content Delivery Network) A geographically distributed network of servers that delivers content to users from locations close to them, reducing latency and bandwidth costs.
Cloud Interconnection Direct connections between networks and cloud service providers (AWS, Azure, Google Cloud, etc.), often facilitated through Internet Exchanges.
Cross-Connect A physical cable connection between two pieces of equipment in a data center, often used to establish private peering connections.
D
DE-CIX Deutscher Commercial Internet Exchange, one of the world's largest Internet Exchange Points, based in Frankfurt, Germany.
E
ECMP (Equal-Cost Multi-Path) A routing strategy that allows traffic to be distributed across multiple paths of equal cost, enabling load balancing.
I
IX (Internet Exchange or Internet Exchange Point) A physical infrastructure where multiple networks interconnect to exchange traffic. Also known as IXP.
IXP (Internet Exchange Point) See IX.
L
LINX (London Internet Exchange) One of the world's largest Internet Exchanges, based in London, UK.
Local Preference A BGP attribute used to influence outbound traffic routing decisions within an autonomous system.
M
MANRS (Mutually Agreed Norms for Routing Security) A global initiative to improve routing security through implementation of filtering, anti-spoofing, coordination, and validation.
MED (Multi-Exit Discriminator) A BGP attribute used to suggest to neighboring ASes which of multiple entry points into your network they should prefer.
MPLS (Multiprotocol Label Switching) A routing technique that directs data along predetermined paths using short path labels rather than long network addresses.
N
NOG (Network Operators Group) Community organizations where network operators share knowledge and discuss technical issues. Examples: NANOG, APRICOT, RIPE.
P
Peering An agreement between two networks to directly exchange traffic, typically settlement-free (no payment exchanged).
PeeringDB A community-maintained database of networks, Internet Exchanges, and facilities, used to coordinate peering relationships.
Prefix A block of IP addresses represented in CIDR notation (e.g., 203.0.113.0/24).
Private Peering A direct, dedicated connection between two networks, typically established via cross-connects in a data center.
Public Peering Peering that occurs at a shared Internet Exchange, where one connection can reach multiple peers.
Q
QoS (Quality of Service) Techniques for managing network resources to prioritize certain types of traffic over others.
R
Remote Peering Connecting to an Internet Exchange without physical presence at the IX location, typically through a carrier's extended services.
Route Hijacking When an AS incorrectly announces IP prefixes it doesn't own, potentially redirecting traffic intended for another network.
Route Leak When routes are announced beyond their intended scope, often due to misconfiguration, potentially causing traffic to flow through unintended paths.
Route Server A service at Internet Exchanges that simplifies peering by allowing members to establish one BGP session and reach many peers.
RPKI (Resource Public Key Infrastructure) A cryptographic framework that validates that an AS is authorized to announce specific IP prefixes, helping prevent route hijacking.
S
SDN (Software-Defined Networking) An approach to networking that uses software-based controllers to manage network behavior, enabling more dynamic traffic engineering.
SLA (Service Level Agreement) A commitment between a service provider and customer that defines expected service levels, often including performance metrics.
SNMP (Simple Network Management Protocol) A protocol used for collecting information from and configuring network devices.
T
Transit A service where one network (the customer) pays another network (the provider) to carry its traffic to the entire Internet.
Tier-1 Network A network that can reach every other network on the Internet without paying for transit, relying solely on peering and its own infrastructure.
V
VLAN (Virtual Local Area Network) A logical network segment that allows separation of traffic on shared physical infrastructure, commonly used at Internet Exchanges.
Additional Resources
For more detailed explanations, see: