Q 4. See the network shown below. The figure consists of four automatous systems (ASs) each running RIP as an internal routing protocol. Moreover, iBGP and eBGP are used as border gateway protocols. AS4 is connected to an external network called x. By carefully examining the figure below, answer the following questions:

1- Which protocol is used to tell router 1b about network x? iBGP, eBGP, RIP or OSPF?

2- Which protocol is used to tell router 2b about network x?

3- Which protocol is used to tell router 3b about network x?

4- Which protocol is used to tell router 1c about network x?

3b 3c AS3 3a 1a 4C 4b AS4 1C 1d AS1 4a 1b 2a 2c AS2 2b