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Enhanced Functionalities

6 important questions on Enhanced Functionalities

How does Link State Multicast work?

Is also called MOSPF --> Multi OSPF

A host announce group memmbership through IGMP. Router checks suchs announcements. The router knows the entire toplogy because of link state routing.

Problems
- it is hard to scale: one tree for each sender to each group
- dependent on link state routing, isnt used everywhere
- not efficient in sparse mode.

Everytime theres a new sender, a new tree structure needs to be made. This becomes a problem when its a difficult network with continues influx of new senders.

How can PIM be optimized?

Optimization
- if a host sends a ton of packages through the system. The the tree structure can be reshaped for this specific source to improve the tunnel length/speed.

What are the advantages of MPLS?

Its a way to make a better performing switch. MPLS isnt bound to IP, not even to packet switching. It makes exact paths and can optimise the spread amongst those paths. And can create easier backup routes. It is similar to Virtual Circuit Switching and therefore also ideal to set up VPNs

What is Explicit Routing?

Sometimes there are two paths. When from one source there is very heavy load of influx packets, lets say video. We then need to label different packets from that source also, so we can reroute those, whilst from the same host. This is done through RSVP. This way the network can be optimally used through: traffic engineering.

How does routing to mobile devices work?

When a mobile host arrives in a wireless spot it can get a new ip address via DHCP. When it moves through this network it can change between APs but keep its original IP. This position change will be handled in layer 2. When it changes network it has to get a new IP address through DHCP.

IP address serves two tasks: identifier and locator

How does Mobile IPv6 work?

Advantages
- no foreign agent needed
- no tunneling required--> more addresses
- multiple mobility options
- security is inherent part of it

Extension for mobile networks (NEMO)
- entire network moves
- nested mobility

Problem: Poor OS support
- Cisco IOS supports it
- only partial by Windows and Linux