ping 命令详解 - DSCP
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2022-06-30 20:48:50
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https://www.jianshu.com/p/0cb93b7b4f64
Linux命令参数详细解析-ping
-
概要
ping [-aAbBdDfhLnOqrRUvV] [-c count] [-F flowlabel] [-i interval] [-I inter‐
face] [-l preload] [-m mark] [-M pmtudisc_option] [-N nodeinfo_option] [-w
deadline] [-W timeout] [-p pattern] [-Q tos] [-s packetsize] [-S sndbuf] [-t
ttl] [-T timestamp option] [hop ...] destination -
描述
ping uses the ICMP protocol's mandatory ECHO_REQUEST datagram to elicit an
ICMP ECHO_RESPONSE from a host or gateway. ECHO_REQUEST datagrams (''pings'') have an IP and ICMP header, followed by a struct timeval and then
an arbitrary number of ``pad'' bytes used to fill out the packet.
ping6 is IPv6 version of ping, and can also send Node Information Queries
(RFC4620). Intermediate hops may not be allowed, because IPv6 source routing
was deprecated (RFC5095). -
操作
-a Audible ping.
-A Adaptive ping. Interpacket interval adapts to round-trip time, so that
effectively not more than one (or more, if preload is set) unanswered
probe is present in the network. Minimal interval is 200msec for not
super-user. On networks with low rtt this mode is essentially equiva‐
lent to flood mode.
-b Allow pinging a broadcast address.
-B Do not allow ping to change source address of probes. The address is
bound to one selected when ping starts.
-c count
Stop after sending count ECHO_REQUEST packets. With deadline option,
ping waits for count ECHO_REPLY packets, until the timeout expires.
-d Set the SO_DEBUG option on the socket being used. Essentially, this
socket option is not used by Linux kernel.
-D Print timestamp (unix time + microseconds as in gettimeofday) before
each line.
-f Flood ping. For every ECHO_REQUEST sent a period ``.'' is printed,
while for ever ECHO_REPLY received a backspace is printed. This pro‐
vides a rapid display of how many packets are being dropped. If
interval is not given, it sets interval to zero and outputs packets as
fast as they come back or one hundred times per second, whichever is
more. Only the super-user may use this option with zero interval.
-F flow label
ping6 only. Allocate and set 20 bit flow label (in hex) on echo
request packets. If value is zero, kernel allocates random flow
label.
-h Show help.
-i interval
Wait interval seconds between sending each packet. The default is to
wait for one second between each packet normally, or not to wait in
flood mode. Only super-user may set interval to values less 0.2 sec‐
onds.
-I interface
interface is either an address, or an interface name. If interface is
an address, it sets source address to specified interface address. If
interface in an interface name, it sets source interface to specified
interface. For ping6, when doing ping to a link-local scope address,
link specification (by the '%'-notation in destination, or by this
option) is required.
-l preload
If preload is specified, ping sends that many packets not waiting for
reply. Only the super-user may select preload more than 3.
-L Suppress loopback of multicast packets. This flag only applies if the
ping destination is a multicast address.
-m mark
use mark to tag the packets going out. This is useful for variety of
reasons within the kernel such as using policy routing to select spe‐
cific outbound processing.
-n Numeric output only. No attempt will be made to lookup symbolic names
for host addresses.
-O Report outstanding ICMP ECHO reply before sending next packet. This
is useful together with the timestamp -D to log output to a diagnostic
file and search for missing answers.
-p pattern
You may specify up to 16 ``pad'' bytes to fill out the packet you
send. This is useful for diagnosing data-dependent problems in a net‐
work. For example, -p ff will cause the sent packet to be filled with
all ones.
-q Quiet output. Nothing is displayed except the summary lines at
startup time and when finished.
-Q tos Set Quality of Service -related bits in ICMP datagrams. tos can be
decimal (ping only) or hex number.
-r Bypass the normal routing tables and send directly to a host on an
attached interface. If the host is not on a directly-attached net‐
work, an error is returned. This option can be used to ping a local
host through an interface that has no route through it provided the
option -I is also used.
-R ping only. Record route. Includes the RECORD_ROUTE option in the
ECHO_REQUEST packet and displays the route buffer on returned packets.
Note that the IP header is only large enough for nine such routes.
Many hosts ignore or discard this option.
-s packetsize
Specifies the number of data bytes to be sent. The default is 56,
which translates into 64 ICMP data bytes when combined with the 8
bytes of ICMP header data.
-S sndbuf
Set socket sndbuf. If not specified, it is selected to buffer not more
than one packet.
-t ttl ping only. Set the IP Time to Live.
-T timestamp option
Set special IP timestamp options. timestamp option may be either
tsonly (only timestamps), tsandaddr (timestamps and addresses) or
tsprespec host1 [host2 [host3 [host4]]] (timestamp prespecified hops).
-U Print full user-to-user latency (the old behaviour). Normally ping
prints network round trip time, which can be different f.e. due to DNS
failures.
-v Verbose output.
-V Show version and exit.
-w deadline
Specify a timeout, in seconds, before ping exits regardless of how
many packets have been sent or received. In this case ping does not
stop after count packet are sent, it waits either for deadline expire
or until count probes are answered or for some error notification from
network.
-W timeout
Time to wait for a response, in seconds. The option affects only time‐
out in absence of any responses, otherwise ping waits for two RTTs.
http://help.sonicwall.com/help/sw/eng/7110/26/2/4/content/Firewall_Managing_QoS.088.3.html
Figure 43. DSCP marking: IP packet
Table 123. DSCP marking: Commonly used code points
5 (CRITIC/ECP1 – 101)