I have one doubt from many days. In case IGRP, EIGRP, BGP we will specify autonomous system number.
But coming to RIP and OSPF we don't specify autonomous system number.
If this is the case, either RIP or OSPF belongs to which autonomous system how to know?
There is absolutely no concept of AS number with RIP or OSPF. The only way to enfore AS boundaries in OSPF and RIP is by the careful use of the 'network' statement so that you only enable the protocols on links which belong to your 'autonomous system'. If you make a mistake and enable RIP on an external-facing interface, and the router at the end is also configured for RIP, RIP will happily exchange routes with this neighbor. As you know, that will not happen with EIGRP or BGP since the AS numbers have to match up.
So, in a nutshell, the answer is that there is no way to enforce the boundary within the protocol itself - you have to set up the boundaries manually.
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