Computer post institutions exam papers network - routing table

Knowledge points:

0.0.0.0: this is a collection that represents: All clear of hosts and the destination network

255.255.255.255: restriction broadcast address, the address can not be forwarded router

 

                                                                       ↓↓↓↓↓↓↓↓↓ Well, we see a direct question ↓↓↓↓↓↓↓↓↓

 

 

 

1. Set the IP address space into two subnets 202.118.1.0/24 assigned to two subnets need to solve at least one from the host bits;

   The number of addresses assigned to each LAN is not less than 120, so at least seven host bits left (2 ^{. 7} > 120, 2 ⁶ <120)

   So borrow one. So subnet mask is 1111 1111 1111 1111 1111 1111 1000 0000 →→ 255.255.255.128, per subnet 128

   Therefore, IP addresses, the two LANs were 202.118.1.0/25,202.118.1.128/25

 2. R1 routing table (IP address of the picture there is an error, to answer questions in IP-based)

The purpose network	Subnet Mask	The next hop IP	interface
LAN 1: 202.118.1.0	255.255.255.128	direct	E1
LAN 2: 202.118.1.128	255.255.255.128	direct	E2
Server: 228.118.3.2	255.255.255.255	202.118.2.2	L0
Internet: 0.0.0.0	0.0.0.0	202.118.12.2	L0

 

3. LAN 1 and LAN 2 may be aggregated into 202.118.1.0/24

        R2 and path leading to the LAN 2 LAN 1 is the same, so long as the routing table to fill in 202.118.1.0/24 on the line.

The purpose network	Subnet Mask	Next hop	interface
202.118.1.0	255.255.255.0	202.118.2.1	L0