TOPEX Bytton (HSPA+ / LTE)
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5.4.3 Dynamic routes
The last configuration page in “Routing” is for dynamic routing. As an alternative to defining static routes
for the connection of your network to the Internet using Bytton, you may choose Dynamic Routing.
Figure 5-118: ROUTING page – section Dynamic Routes.
You may select to leave the Dynamic Routing Disabled (the default
setting) or to use either RIP, OSPF or BGP algorithm for dynamic
routing.
In the Dynamic mode of routing, you need not specify fixed routes. Instead, the router adjusts
automatically to physical changes in the layout of the network and it exchanges routing tables with other
routers.
The available options for dynamic routes are:
RIP
- Routing Information Protocol.
It was the first routing protocol implemented for dynamic routing and hence it is widely used. RIP is a
distance-vector routing protocol.
The route of the data packets is determined in such way as to have the fewest possible number of hops
between the source and the destination.
OSPF
- Open Shortest Path First.
This is a link state routing protocol, as opposed to distance vector protocol (RIP). It is an Internet standard
IGP defined in RFCs 1583 1793 and RFC 2328.
OSPF Runs directly over IP and interfaces with SNMP for configuration and control purposes.
As a link-state routing protocol, OSPF contrasts with RIP and IGRP, which are distance -vector routing
protocols
The SPF (shortest path first) algorithm used by OSPF has the advantage is that it results in smaller more
frequent updates everywhere, thus it makes for a stable network.
Its disadvantage is that it is intensive, it requires for processing more CPU power and memory.
BGP
- Border Gateway Protocol).
It is a protocol for exchanging routing information between gateway hosts (each has its own router) in a
network of “autonomous systems” (AS). For this, it maintains a table of IP networks or 'prefixes' which
designate network reach-ability among autonomous systems.
BGP does not use traditional Interior Gateway Protocol (IGP) metrics like RIP or OSPF, but instead makes
routing decisions based on path, network policies and/or rule-sets.
BGP has been created to replace the Exterior Gateway Protocol (EGP) protocol to allow fully
decentralized routing in order to transition from the core network model to a decentralized system that is
more like the present day Internet.
Since 1994, version four of the BGP has been in use on the Internet. All previous versions are now
obsolete. And since January 2006, version 4 is codified in RFC 4271, which went through more than 20
drafts based on the earlier RFC 1771 version 4.
