Dynamic Routing -gated services aix

                In TCP/IP, routing can be one of two types: 

 1.  Static  routing
2.  Dynamic routing

 With static routing, you maintain the routing table manually using the route command. Static routing is practical for a single network communicating with one or two other networks.

* Note -  However, as your network begins to communicate with more networks, the number of gateways increases, and so does the amount of time and effort required to maintain the routing table manually.
With dynamic routing, daemons update the routing table automatically. Routing daemons continuously receive information broadcast by other routing daemons, and so continuously update the routing table.

 In AIX  , TCP/IP  provides two daemons for use in dynamic routing,

1.  routed  deamon

2.  gated daemon

The gated daemon supports  

 a)Routing Information Protocol (RIP) & Routing Information Protocol Next Generation (RIPng)

 b)Exterior Gateway Protocol (EGP), 

 c)Border Gateway Protocol (BGP) and BGP4+, 

 d)Defense Communications Network Local-Network Protocol (HELLO), 

 e)Open Shortest Path First (OSPF), 

 f) Simple Network Management Protocol (SNMP) and some more 

Routing daemons can operate in one of two modes,

1.  passive 

2.  active,  

In active mode, routing daemons both broadcast routing information periodically about their local network to gateways and hosts, and receive routing information from hosts and gateways.

                                                              In passive mode, routing daemons receive routing information from hosts and gateways, but do not attempt to keep remote gateways updated (they do not advertise their own routing information).

                                              Dynamic routing daemons, however, must be run in the passive (quiet) mode when run on a host that is not a gateway.

Recently came across environment where gated services where used with OSPF routing protocol

       This was something new for me ,so started reading the pdf's and blogs to understand the exact concepts. 

               

The most important point is that if you want to understand the complete configuration ,you first need to understand the Routing protocol and it's working and it's network terms  .

Now let us go through the basic concept   of the OSPF routing protocol that will be helpful in configuration 

OSPF 

• Dynamic Routing Protocol 
•  Link State technology 
• Runs over IP, protocol 89 
•  Designed by IETF for TCP/IP 
• Supports VLSM   -- It supports subnetting 
• Multi-vendor   - It is standard protocol  and supported by all the vendor's 
• Fast rerouting - OSPF detects changes in the topology, such as link failures, and converges on a new loop-free routing structure within seconds.
• Minimises routing protocol traffic 

• Low bandwidth requirements 
•  Supports different types of areas 
• Route summarisation and authentication

 Under construction  ....