onsider the network shown below. Suppose AS3 and AS2 are running OSPF for their intra-AS routing protocol. Suppose AS1 and AS4 are running RIP for their intra-AS routing protocol. Suppose eBGP and iBGP are used for the inter-AS routing protocol. Initially suppose there is no physical link between AS2 and AS4.

Router 2c learns about prefix x from which routing protocol: OSPF, RIP, eBGP, or iBGP?

Router 2a learns about x from which routing protocol?

Router 1c learns about x from which routing protocol?

eBGP

Router 1d learns about x from which routing protocol?

iBGP

Repeat the above four questions but with the assumption that there is a physical link between AS2 and AS4 (the dotted line).