1. Introduction To Internetworking Flashcards
definition of internetwork
You create an internetwork when you connect two or more networks via a router and configure a logical network addressing scheme with protocols like IP or IPv6
SOHO
Small Office Home Office
Collision domain
Broadcast domain
List some of the things that commonly cause LAN traffic congestion
• Too many hosts in a collision or broadcast domain
• Broadcast storms.
• Too much multicast traffic
• Low bandwidth
• Adding hubs for connectivity to the network
• A bunch of ARP broadcasts
What is a hub?
What is a switch?
What is a router?
What serial connection on a router could be used to access a WAN?
V.35 physical interface
What are two advantages of using routers in your network?
- They don’t forward broadcasts by default.
- They can filter the network based on layer three (network layer) information such as an IP address
Definition of latency?
Latency is the time measured from when a frame enters a port to when it exits a port
What does a filter table do in a switch?
When a layer 2 switch receives a frame, it will store the source hardware address and receiving port in a filter table to track specific sending devices
True or false, each port on a switch has its own collision domain?
True
What’s the difference between layer two and layer three devices?
Layer 3 machines like routers need to locate specific networks.
Layer 2 machines like switches and bridges need to eventually locate specific devices.
Networks are to routers as individual devices are to switches and bridges. Rooting tables that map the network are for routers as filter tables that map individual devices are for switches and bridges.
What is transparent bridging?
What will a switch do if it receives a frame with a destination hardware address that isn’t found in its filter table?
It will forward the frame to all connected segments. If the unknown device that was sent the frame replies, the switch updates its filter table regarding that devices location.
(In the event that the destination address of the transmitting frame is a broadcast address the switch will forward all broadcast to every connected segment by default)
How can you stop a broadcast at storm from propagating through an internetwork?
Use a layer 3 device (router) All devices that a broadcast is forwarded to are considered to be in the same broadcast domain, this can be a problem because layer 2 devices propagate layer 2 broadcast storms which can seriously choke performance. The only way to stop a broadcast storm from propagating through an internetwork is with a layer three device (a router)
What is Cisco‘s NGFW called?
Who did they acquire it from?
Firepower
Acquired from Sourcefire in 2013
IPS
Intrusion Prevention System
NGFW
Next Generation Firewall
NGFW is considered third generation firewall technology that provides a full packet reassembly and deep packet inspection up to and through layer 7.
NGFW’s are popular because they permit AVC as well as offer IPS policies, which help us look for attacks on unknown client vulnerabilities
AVC
Application Visibility and Control
Why are NGFW’s so expensive?
To provide features like SSL decryption at close to wire speed, you’ve got to have hardware encryption acceleration capabilities which are not cheap
What features would you expect in a NGFW?
• Be router and switch compatible (L2/L3)
• Include packet filtering with IPS and malware inspection capability
• Provide network address translation (NAT)
• Permit stateful inspection
• Permit virtual private networks (VPNs)
• Provide URL and application filtering
• Implement QoS
• Support third-party integration
• Support REST API
FTD
Firepower Threat Defence
Cisco’s new line of NGFW devices