134
C
HAPTER
6: C
ONFIGURING
AND
M
ANAGING
IP I
NTERFACES
AND
S
ERVICES
To identify the next hop, traceroute again sends a UDP packet, but this
time with a TTL value of 2. The first router decrements the TTL field by 1
and sends the datagram to the next router. The second router sees a TTL
value of 1, discards the datagram, and returns the
Time Exceeded
message to the source. This process continues until the TTL is
incremented to a value large enough for the datagram to reach the
destination host (or until the maximum TTL is reached).
To determine when a datagram has reached its destination, traceroute
sets the UDP destination port in the datagram to a very large value, one
that the destination host is unlikely to be using. In addition, when a host
receives a datagram with an unrecognized port number, it sends an ICMP
Port Unreachable
error to the source. This message indicates to the
traceroute facility that it has reached the destination.
To trace a route to a destination subnet, use the following command:
traceroute host
[
dnf
] [
no-dns
] [
port
port-num
] [
queries
num
]
[
size
size
] [
ttl
hops
] [
wait
ms
]
To trace the route to host
server1
, type the following command:
WX1200#
traceroute server1
traceroute to server1.example.com (192.168.22.7), 30 hops max, 38 byte packets
1 engineering-1.example.com (192.168.192.206) 2 ms 1 ms 1 ms
2 engineering-2.example.com (192.168.196.204) 2 ms 3 ms 2 ms
3 gateway_a.example.com (192.168.1.201) 6 ms 3 ms 3 ms
4 server1.example.com (192.168.22.7) 3 ms * 2 ms
In this example,
server1
is four hops away. The hops are listed in order,
beginning with the hop that is closest to the WX switch and ending with
the route’s destination. (For information about the command options, see
the
Wireless LAN Switch and Controller Command Reference
.)
Summary of Contents for 3CRWX120695A
Page 138: ...138 CHAPTER 6 CONFIGURING AND MANAGING IP INTERFACES AND SERVICES ...
Page 272: ...272 CHAPTER 11 CONFIGURING RF LOAD BALANCING FOR MAPS ...
Page 310: ...310 CHAPTER 13 CONFIGURING USER ENCRYPTION ...
Page 322: ...322 CHAPTER 14 CONFIGURING RF AUTO TUNING ...
Page 350: ...350 CHAPTER 16 CONFIGURING QUALITY OF SERVICE ...
Page 368: ...368 CHAPTER 17 CONFIGURING AND MANAGING SPANNING TREE PROTOCOL ...
Page 412: ...412 CHAPTER 19 CONFIGURING AND MANAGING SECURITY ACLS ...
Page 518: ...518 CHAPTER 21 CONFIGURING AAA FOR NETWORK USERS ...
Page 530: ...530 CHAPTER 22 CONFIGURING COMMUNICATION WITH RADIUS ...
Page 542: ...542 CHAPTER 23 MANAGING 802 1X ON THE WX SWITCH ...
Page 598: ...598 CHAPTER 26 ROGUE DETECTION AND COUNTERMEASURES ...
Page 706: ...706 GLOSSARY ...