Internet Control Message Protocol (ICMP)
On systems without the BSD routing socket, Advanced Routing Suite listens to ICMP messages received by the system. Advanced Routing Suite supports redirect with the router redirect command.
Enter ICMP Router Configuration mode to trace the ICMP messages that Advanced Routing Suite receives. These messages can be traced to a separate log file, as is allowed by any Advanced Routing Suite trace file command. This allows for easy separation of non-redirect ICMP messages from redirect messages in the trace file.
router icmp
Name
router icmp - allows the user to enter ICMP Router Configuration Mode
Syntax
router icmp
Mode
Global Configuration
Parameters
none
Description
The router icmp command allows you to enter ICMP Router Configuration mode, where, currently only tracing options are supported.
Note: Because ICMP is always on, a negative form of this command is not available. Type exit at the (config-icmp)# prompt to leave ICMP Router Configuration mode.
Default
none
Command History
NGC 2.2 - This command was introduced.
Examples
The following example shows how to enter and exit ICMP Router Configuration mode on this router.
(config)# router icmp
(config-icmp)# exit
(config)#
trace file
Name
trace file - specifies file options during tracing for the ICMP protocol
Syntax
trace file file_name [|| no-timestamp || overwrite]?
no trace file file_name [ no-timestamp || overwrite]?
Mode
ICMP Router Configuration Mode
Parameters
file_name - specifies the name of the file to receive the tracing information. Note that the file name is not specified in quotes.
no-timestamp - specifies that a timestamp should not be prepended to all trace lines
overwrite - specifies to begin tracing by appending or truncating an existing file
Description
The trace file command is associated with each protocol, so that information pertaining to a single protocol can be written to its own file. For ICMP, the trace file command in ICMP Router Configuration Mode specifies a file for tracing of all ICMP events. The negative form of this command disables this tracing. The specific events that are traced are controlled by the trace flag command.
The no-timestamp option disables the pre-pending of a timestamp to all lines written to the trace file. The default is to prepend a timestamp to all lines written to a trace file.
The overwrite option specifies whether to start tracing by truncating or appending to an existing file.
Note: These options are not cumulative across multiple commands. Consider the following example:
(config-icmp)# trace file /var/log/icmp.log no-timestamp
(config-icmp)# trace file /var/log/icmp.log
The option given in the second command completely replaces that given in the first.
Default
ICMP tracing is turned off by default.
Command History
NGC 2.2 - This command was introduced.
Examples
In the following example, ICMP tracing is written to the file "/var/tmp/icmp.log". No timestamp will display at the beginning of the trace lines.
(config)# router icmp
(config-icmp)# trace file /var/tmp/icmp.log no-timestamp
trace flag
Name
trace flag - specifies additional tracing flags for ICMP tracing
Syntax
trace flag ( [ route | normal | state | policy | task |
timer | all ] ) | ( [ packet | redirect |
router-discovery | info | error ] [ send | receive |
send-receive ]? [detail?] )
no trace flag ( [ route | normal | state | policy | task |
timer | all ] ) | ( [ packet | redirect |
router-discovery | info | error ] [ send | receive |
send-receive ]? [detail?] )
Mode
ICMP Router Configuration
Parameters
Flags common to all protocols:
[ route | normal | state | policy | task | timer | all ] - These tracing flags are common to all protocols. They cannot be associated with a send, receive, or send-receive action item. Similarly, you cannot specify to show detailed information when tracing these flags. These flags are defined as follows:
route - trace routing table changes for routes installed by this protocol or peernormal - trace normal protocol occurrences. Note: Abnormal protocol occurrences are always traced.state - trace state machine transition in the protocolpolicy - trace the application of protocol and user-specified policy to routes being imported or exportedtask - trace system interface and processing associated with this protocoltimer - trace timer usage by this protocolall - turns on all trace flags
ICMP-specific flags:
[ packet | redirect | router-discovery | info | error ] - These ICMP-specific flags can be associated with the send, receive, or send-receive action items. These flags are defined as follows:packets - trace all ICMP packet typesredirect - trace only ICMP redirect packetsrouter-discovery - trace only ICMP router discovery packetsinfo - trace only ICMP informational packets, which include mask request/response, info request/response, echo request/response, and time stamp request/responseerror - trace only ICMP error packets, which include time exceeded, parameter problem, unreachable, and source quench[ send | receive | send-receive ]? - optionally specify whether to limit the tracing to packets sent, received, or both[detail?] - optionally specify to use a more verbose format when displaying information about the contents of packets instead of one or two lines
Description
Use the trace flag command to specify tracing flags for ICMP tracing. Each flag must reside on its own configuration line. For example, you cannot specify to trace both redirect and info packets in the same command.
Default
The default is for no flags to be explicitly configured.
Command History
NGC 2.2 - This command was introduced.
Examples
In the following example, trace flags specify that both the sent and received request and response messages are traced in detail. This tracing information will be written to the file /var/tmp/icmp.log.
(config)# router icmp
(config-icmp)# trace file /var/tmp/icmp.log
(config-icmp)# trace flag request send-receive detail
(config-icmp)# trace flag response send-receive detail
See Also
Trace Options
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