T316/THE-Final5of112020-2021/FallQuestion 4: (5 marks)Consider the network shownin Figure 2. Suppose AS3 and AS2 are running OSPF for theirintra-AS routing protocol. Suppose AS1 and AS4 are running RIP for their intra-AS routingprotocol. Suppose eBGP and iBGP are used for the inter-AS routing protocol. Initially supposethere isnophysical link between AS2 and AS4.a.Router 3c learns about prefixxfrom which routing protocol: OSPF, RIP, eBGP, or iBGP?b.Router 3a learns aboutxfrom which routing protocol?c.Router 1c learns aboutxfrom which routing protocol?d.Router 1d learns aboutxfrom whichrouting protocol?e.Once router 1d learns aboutxit will put an entry (x,I) in its forwarding table. WillIbe equaltoI1 orI2 for this entry? Explain why in one sentence.f.Now suppose that there is a physical link between AS2 and AS4, shown by the dotted line.Suppose router 1d learns thatxis accessible via AS2 as well as via AS3. WillIbe set toI1 orI2? Explain why in one sentence.g.Now suppose there is another AS, called AS5, which lies on the path between AS2 andAS4 (not shown in diagram). Suppose router 1d learns thatxis accessible via AS2 AS5AS4 as well as via AS3 AS4. WillIbe set toI1 orI2? Explain why in one sentence.