dropwatch(1) General Commands Manual dropwatch(1)NAME
dropwatch - kernel dropped packet monitoring utility
dropwatch [-l <method> | list]
dropwatch dropwatch is an interactive utility for monitoring and recording packets that are dropped by the kernel
OPTIONS -l <method> | list
Select the translation method to use when a drop alert arrives. By default the raw instruction pointer of a drop location is out-
put, but by the use of the -l option, we can assign a translation method so that the instruction pointer can be translated into
function names. Currently supported lookup methods are:
kas - use /proc/kallsyms to lookup instruction pointers to function mappings
start Tells the kernel to start reporting dropped packets
stop Tells the kernel to discontinue reporting dropped packets
exit Exits the dropmonitor program
help Displays summary of all commands
set alertlimit <value>
Sets a triggerpoint to stop monitoring for dropped packets after <value> alerts have been received
Neil Horman Mar 2009 dropwatch(1)
Check Out this Related Man Page
PCAP_STATS(3) Library Functions Manual PCAP_STATS(3)NAME
pcap_stats - get capture statistics
int pcap_stats(pcap_t *p, struct pcap_stat *ps);
pcap_stats() fills in the struct pcap_stat pointed to by its second argument. The values represent packet statistics from the start of the
run to the time of the call.
pcap_stats() is supported only on live captures, not on ``savefiles''; no statistics are stored in ``savefiles'', so no statistics are
available when reading from a ``savefile''.
A struct pcap_stat has the following members:
number of packets received;
number of packets dropped because there was no room in the operating system's buffer when they arrived, because packets
weren't being read fast enough;
number of packets dropped by the network interface or its driver.
The statistics do not behave the same way on all platforms. ps_recv might count packets whether they passed any filter set with pcap_set-
filter(3) or not, or it might count only packets that pass the filter. It also might, or might not, count packets dropped because there
was no room in the operating system's buffer when they arrived. ps_drop is not available on all platforms; it is zero on platforms where
it's not available. If packet filtering is done in libpcap, rather than in the operating system, it would count packets that don't pass
the filter. Both ps_recv and ps_drop might, or might not, count packets not yet read from the operating system and thus not yet seen by
the application. ps_ifdrop might, or might not, be implemented; if it's zero, that might mean that no packets were dropped by the inter-
face, or it might mean that the statistic is unavailable, so it should not be treated as an indication that the interface did not drop any
pcap_stats() returns 0 on success and returns -1 if there is an error or if p doesn't support packet statistics. If -1 is returned,
pcap_geterr() or pcap_perror() may be called with p as an argument to fetch or display the error text.
SEE ALSO pcap(3), pcap_geterr(3)
7 September 2009 PCAP_STATS(3)
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