Question

CIDR. The table below is a routing table using Classless Interdomain Routing (CIDR). Address bytes for the subnet number as well as the subnet mask are h hexadecimal notation. Thus, the subnet number 128.46.101.0 is represented as 80.2E.65.0 and the subnet mask 255.255.255.0 is represented as FF.FF.FF.0 Next Hop Subnet Number C4.5E.40.0 C4.5E.4F.0 C4.50.0.0 C4.5E.0.0 Default Subnet Mask FF FF F0.00 FF FF.FF.00 FF F0.00.00 FF FF.00.00 State to what next hop a packet for the following destination IP addresses will be delivered. No explanation is needed for any part of this problem. [4 x 4 16 points] (a) C4.SE4.I (b) C4.5E.4E.23 (c) C4.5B.4F.2E (d) C4.SE.FF.85

Answer 1

Before we proceed, we must keep this in mind that we should always priotize the longest mask

C4.5E.4.1
   Apply MASK: FF.FF.FF.00, we get subnet number: C4.5E.04.00 (NO MATCH)
   Apply MASK: FF.FF.F0.00, we get subnet number: C4.5E.00.00 (NO MATCH)
   Apply MASK: FF.FF.00.00, we get subnet number: C4.5E.00.00 (MATCH)

   So Next hop is D

C4.5E.4E.23
   Apply MASK: FF.FF.FF.00, we get subnet number: C4.5E.4E.00 (NO MATCH)
   Apply MASK: FF.FF.F0.00, we get subnet number: C4.5E.40.00 (MATCH)

   So Next hop is A

C4.5B.4F.23
   Apply MASK: FF.FF.FF.00, we get subnet number: C4.5B.4F.00 (NO MATCH)
   Apply MASK: FF.FF.F0.00, we get subnet number: C4.5B.40.00 (NO MATCH)
   Apply MASK: FF.FF.00.00, we get subnet number: C4.5B.00.00 (NO MATCH)
   Apply MASK: FF.F0.00.00, we get subnet number: C4.50.00.00 (NO MATCH)

   So Next hop is C

C4.5E.FF.85
   Apply MASK: FF.FF.FF.00, we get subnet number: C4.5E.FF.00 (NO MATCH)
   Apply MASK: FF.FF.F0.00, we get subnet number: C4.5E.F0.00 (NO MATCH)
   Apply MASK: FF.FF.00.00, we get subnet number: C4.5E.00.00 (NO MATCH)

   So Next hop is D