Hybrid Networking Flashcards
the concepts of BGP and IPSec, and the hybrid networking AWS services such as Direct Connect and Site-to-Site VPN.
What standardized exterior gateway protocol is designed to exchange routing and reachability information among autonomous systems on the Internet?
Border Gateway Protocol (BGP)
What is the primary purpose of Border Gateway Protocol (BGP)?
BGP is a path-vector protocol designed to exchange the best path to a destination between peers, this path is referred to as the AS_PATH (Autonomous System Path)
Which TCP port does Border Gateway Protocol (BGP) use?
TCP port 179
Does Border Gateway Protocol (BGP) require manual configuration?
Yes, BGP peering must be configured manually, it is not automatic
What path does Border Gateway Protocol (BGP) prefer by default?
Shortest path to the destination
Using Border Gateway Protocol (BGP) is it possible to artificially make certain paths appear longer, causing other paths to be preferred?
Yes, using AS_PATH Prepending:
- Example 1 appears shorter to BGP:
DES 10.18.0.0/16 | NEXT HOP 10.17.0.1 | AS_PATH 201, 202, i - Example 2 appears longer to BGP:
DES 10.18.0.0/16 | NEXT HOP 10.18.0.1 | AS_PATH 202, 202, 202, i
Which AWS networking services utilize Border Gateway Protocol (BGP)?
- AWS Direct Connect
- AWS Site-to-Site VPN (Dynamic)
What term is used to describe routers controlled by a single network entity?
Autonomous System (AS), each AS is assigned an Autonomous System Number (ASN) by IANA.
What is the difference between Interior Border Gateway Protocol (iBGP) and Exterior Border Gateway Protocol (eBGP)?
- iBGP: Propagates routes within a single Autonomous System (AS)
- eBGP: Propagates routes between different Autonomous Systems (ASs)
What AWS service enables a private, physical connection between customer facilities and AWS?
AWS Direct Connect
AWS Region ↔ DX Location ↔ Customer Premises
What does ordering AWS Direct Connect involve?
Ordering Direct Connect involves requesting a dedicated port at an AWS DX Location, enabling physical connectivity to AWS services
Can AWS Direct Connect be used to access only private resources within a VPC?
No, DX can be used to access both private resources within a VPC and public AWS services
Can AWS Direct Connect be used to access the public internet?
No, DX cannot be used to access the public internet, it is designed for private connections to AWS services
What are the cost components of AWS Direct Connect?
- Hourly Port Allocation Fee: Charged for reserving the DX port
- Outbound Data Transfer Charges: Data sent from AWS to your premises (inbound is free)
What types of connections does AWS Direct Connect offer?
- Dedicated Connection: Provided directly by AWS, using an Ethernet port allocated exclusively for a single customer
- Hosted Connection: Offered by an AWS Direct Connect Partner, utilizing their existing network link to AWS
What network speed options are available for AWS Direct Connect?
- Dedicated Connections: 1 Gbps, 10 Gbps, 100 Gbps, 400 Gbps
- Hosted Connections: 50 Mbps to 25 Gbps in increments (e.g., 50 Mbps, 100 Mbps, 200 Mbps, 300 Mbps, 400 Mbps, 500 Mbps, 1 Gbps, 2 Gbps, 5 Gbps, 10 Gbps, and 25 Gbps)
What factors should be considered when using AWS Direct Connect?
- Establishes a private network connection to AWS
- Offers low latency and high-speed connectivity
- Requires provisioning time (can take weeks or months)
- Does not include built-in redundancy; resilience must be implemented with multiple connections
What AWS Direct Connect component enables access to AWS public or private services?
Virtual Interface (VIF)
Which two types of Virtual Interfaces (VIFs) does AWS Direct Connect provide?
- Public VIF: Provides access to AWS public services (e.g., S3, DynamoDB)
- Private VIF: Provides access to private AWS services within a VPC
Which AWS Direct Connect Virtual Interface (VIF) is used to access AWS Public services like S3?
Public VIF
Path: Customer Router → Customer DX Router → AWS DX Router → AWS Public Space
Which AWS Direct Connect Virtual Interface (VIF) is used to access AWS Private services like an EC2 instance in a VPC?
Private VIF
Path: Customer Router → Customer DX Router → AWS DX Router → VGW → VPC
What are the components of an AWS Direct Connect (DX) connection, and is it inherently resilient?
- DX Location
- DX Router
- Cross Connect
- Customer DX Router
- Extension Cables
- Customer Premises
- Customer Router
Resilience is not built-in and must be planned separately
How is resiliency achieved with AWS Direct Connect (DX)?
- Option 1: Use multiple cross-connects from DX routers to multiple customer DX routers and extend these connections with multiple cables to multiple customer premises routers.
(DX Location, cables, or premises can still fail) - Option 2: Achieve maximum resiliency by combining Option 1 with two geographically separated DX locations and connecting them to two separate customer premises data centers
How can the security of AWS Direct Connect (DX) be enhanced?
- Using a VPN over Public VIF ensures performance and security by providing an encrypted and authenticated tunnel with low and consistent latency, using Public VIF and VGW/TGW public endpoints
Which AWS service provides a central hub to simplify complex peering relationships by connecting VPCs and on-premises networks?
AWS Transit Gateway
Does AWS Transit Gateway support transitive connections?
Yes, it enables a hub-and-spoke topology for VPCs and on-premises networks