3Com 400 Family, Configuration Manual

Page: 242 / 344

240 C
HAPTER
12: F
ILE
S
YSTEM
M
ANAGEMENT
Table 269 Test Periodically if the IP address is Reachable
The Switch can ping an IP address every one minute to test if it is reachable. Three
PING packets can be sent at most for every IP address in every testing with a time
interval of five seconds. If the Switch cannot successfully ping the IP address after
the three PING packets, it assumes that the IP address is unreachable.
You can configure up to 50 IP addresses by using the command repeatedly.
tracert
The
tracert
is used for testing the gateways passed by the packets from the
source host to the destination one. It is mainly used for checking if the network is
connected and analyzing where the fault occurs in the network.
The execution process of
tracert
is described as follows: Send a packet with TTL
value as 1 and the first hop sends back an ICMP error message indicating that the
packet cannot be sent, for the TTL is timeout. Re-send the packet with TTL value
as 2 and the second hop returns the TTL timeout message. The process is carried
over and over until the packet reaches the destination. The purpose to carry out
the process is to record the source address of each ICMP TTL timeout message, so
as to provide the route of an IP packet to the destination.
Perform the following operation in all views.
Figure 67 The tracert Command
Logging Function
Introduction to
Info-center
The Info-center serves as an information center of the system software modules.
The logging system is responsible for most of the information outputs, and it also
makes detailed classification to filter the information efficiently. Coupled with the
debugging program, the info-center provides powerful support for network
administrators and support personnel to monitor the operating state of networks
and diagnose network failures.
When the log information is output to terminal or log buffer, the following parts
will be included:
%Timestamp Sysname Module name/Severity/Digest: Content
For example:
%Jun 7 05:22:03 2003 4500 IFNET/6/UPDOWN:Line protocol on interface
Ethernet1/0/2, changed state to UP
Operation Command
Configure the IP address
requiring periodical testing
end-station polling ip-address
ip-address
Delete the IP address requiring
periodical testing
undo end-station polling ip-address
ip-address
Operation Command
Trace route
tracert [ -a source-IP ] [ -f first-TTL ] [ -m max-TTL ]
[ -p port ] [ -q nqueries ] [ -w timeout ] string