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Unformatted text preview: ptions. Check your system's manual for these details. 3.9 netstat Command
The netstat(l) command also provides information about the interfaces on a system. The -i
flag prints the interface information, and the -n flag prints IP addresses instead of hostnames.
sun % netstat -in
Name Mtu Net/Dest
lpkts lerrs Opkts Oerrs Collis Queue
leO 1500 126.96.36.199 188.8.131.52 67719 0
slO 552 184.108.40.206 220.127.116.11 48035 0
loO 1536 127.0.0.0
This command prints the MTU of each interface, the number of input packets, input errors, output
packets, output errors, collisions, and the current size of the output queue.
We'll return to the netstat command in Chapter 9 when we use it to examine the routing table,
and in Chapter 13 when we use a modified version to see active multicast groups. 3.10 IP Futures
There are three problems with IP. They are a result of the phenomenal growth of the Internet over
the past few years. (See Exercise 1.2 also.)
1. Over half of all class B addresses have already been allocated. Current estimates predict
exhaustion of the class B address space around 1995, if they continue to be allocated as they
have been in the past.
2. 32-bit IP addresses in general are inadequate for the predicted long-term growth of the
3. The current routing structure is not hierarchical, but flat, requiring one routing table entry
per network. As the number of networks grows, amplified by the allocation of multiple class
C addresses to a site with multiple networks, instead of a single class B address, the size of
the routing tables grows.
CIDR (Classless Interdomain Routing) proposes a fix to the third problem that will extend the
usefulness of the current version of IP (IP version 4) into the next century. We discuss it in more file:///D|/Documents%20and%20Settings/bigini/Docu...homenet2run/tcpip/tcp-ip-illustrated/ip_inter.htm (17 of 19) [12/09/2001 14.46.37] Chapter 3. IP: Internet Protocol detail in Section 10.8.
Four proposals have been...
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This test prep was uploaded on 04/04/2014 for the course ECE EL5373 taught by Professor Guoyang during the Spring '12 term at NYU Poly.
- Spring '12