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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 14:18:53 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 14:18:53 +0000 |
commit | a0e0018c9a7ef5ce7f6d2c3ae16aecbbd16a8f67 (patch) | |
tree | 8feaf1a1932871b139b3b30be4c09c66489918be /man/man8/ip-tcp_metrics.8 | |
parent | Initial commit. (diff) | |
download | iproute2-upstream.tar.xz iproute2-upstream.zip |
Adding upstream version 6.1.0.upstream/6.1.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'man/man8/ip-tcp_metrics.8')
-rw-r--r-- | man/man8/ip-tcp_metrics.8 | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/man/man8/ip-tcp_metrics.8 b/man/man8/ip-tcp_metrics.8 new file mode 100644 index 0000000..5d2dac8 --- /dev/null +++ b/man/man8/ip-tcp_metrics.8 @@ -0,0 +1,143 @@ +.TH "IP\-TCP_METRICS" 8 "23 Aug 2012" "iproute2" "Linux" +.SH "NAME" +ip-tcp_metrics \- management for TCP Metrics +.SH "SYNOPSIS" +.sp +.ad l +.in +8 +.ti -8 +.B ip +.RI "[ " OPTIONS " ]" +.B tcp_metrics +.RI "{ " COMMAND " | " +.BR help " }" +.sp + +.ti -8 +.BR "ip tcp_metrics" " { " show " | " flush " } +.IR SELECTOR + +.ti -8 +.BR "ip tcp_metrics delete " [ " address " ] +.IR ADDRESS + +.ti -8 +.IR SELECTOR " := " +.RB "[ [ " address " ] " +.IR PREFIX " ]" + +.SH "DESCRIPTION" +.B ip tcp_metrics +is used to manipulate entries in the kernel that keep TCP information +for IPv4 and IPv6 destinations. The entries are created when +TCP sockets want to share information for destinations and are +stored in a cache keyed by the destination address. The saved +information may include values for metrics (initially obtained from +routes), recent TSVAL for TIME-WAIT recycling purposes, state for the +Fast Open feature, etc. +For performance reasons the cache can not grow above configured limit +and the older entries are replaced with fresh information, sometimes +reclaimed and used for new destinations. The kernel never removes +entries, they can be flushed only with this tool. + +.SS ip tcp_metrics show - show cached entries + +.TP +.BI address " PREFIX " (default) +IPv4/IPv6 prefix or address. If no prefix is provided all entries are shown. + +.LP +The output may contain the following information: + +.BI age " <S.MMM>" sec +- time after the entry was created, reset or updated with metrics +from sockets. The entry is reset and refreshed on use with metrics from +route if the metrics are not updated in last hour. Not all cached values +reset the age on update. + +.BI cwnd " <N>" +- CWND metric value + +.BI fo_cookie " <HEX-STRING>" +- Cookie value received in SYN-ACK to be used by Fast Open for next SYNs + +.BI fo_mss " <N>" +- MSS value received in SYN-ACK to be used by Fast Open for next SYNs + +.BI fo_syn_drops " <N>/<S.MMM>" "sec ago" +- Number of drops of initial outgoing Fast Open SYNs with data +detected by monitoring the received SYN-ACK after SYN retransmission. +The seconds show the time after last SYN drop and together with +the drop count can be used to disable Fast Open for some time. + +.BI reordering " <N>" +- Reordering metric value + +.BI rtt " <N>" us +- RTT metric value + +.BI rttvar " <N>" us +- RTTVAR metric value + +.BI ssthresh " <SSTHRESH>" +- SSTHRESH metric value + +.BI tw_ts " <TSVAL>/<SEC>" "sec ago" +- recent TSVAL and the seconds after saving it into TIME-WAIT socket + +.SS ip tcp_metrics delete - delete single entry + +.TP +.BI address " ADDRESS " (default) +IPv4/IPv6 address. The address is a required argument. + +.SS ip tcp_metrics flush - flush entries +This command flushes the entries selected by some criteria. + +.PP +This command has the same arguments as +.B show. + +.SH "EXAMPLES" +.PP +ip tcp_metrics show address 192.168.0.0/24 +.RS 4 +Shows the entries for destinations from subnet +.RE +.PP +ip tcp_metrics show 192.168.0.0/24 +.RS 4 +The same but address keyword is optional +.RE +.PP +ip tcp_metrics +.RS 4 +Show all is the default action +.RE +.PP +ip tcp_metrics delete 192.168.0.1 +.RS 4 +Removes the entry for 192.168.0.1 from cache. +.RE +.PP +ip tcp_metrics flush 192.168.0.0/24 +.RS 4 +Removes entries for destinations from subnet +.RE +.PP +ip tcp_metrics flush all +.RS 4 +Removes all entries from cache +.RE +.PP +ip -6 tcp_metrics flush all +.RS 4 +Removes all IPv6 entries from cache keeping the IPv4 entries. +.RE + +.SH SEE ALSO +.br +.BR ip (8) + +.SH AUTHOR +Original Manpage by Julian Anastasov <ja@ssi.bg> |