17 www-uka.rz.uni-karlsruhe.de (129.13.64.69) 160 ms 159 ms 160 ms
Diese Zeile habe ich aus einem Beitrag von dir. Was bedeutet
„ms“
Millisekunden. Also Tausendstel.
und für was stehen die drei Zahlen (160, 159, 160).
Es wurden drei Testpakete an den Server gesendet und die Zeit (in ms) gemessen, bis sie wieder da waren.
Und
was bedeutet das hier:
www-uka.rz.uni-karlsruhe.de (129.13.64.69)
www.uni-karlsruhe.de ergibt - im „Internet-Telefonbuch“ (DNS)nachgefragt, die Nummer 129.13.64.69. Wenn man fragt, welcher Name zur nummer gehört, bekommt man www-uka.rz.uni-karlsruhe.de als Antwort. Widerspruch? Nein. Wenn jemand Dienen Sohn fragt, welche Nummer er hat, wird er die Nummer von zuhause nenne. Die Telekom sagt jedoch, es sei Dein Anschluss…
Ist das der Provider, über den der Benutzer mit der IP
129.13.64.69 ins Internet geht.
Umm. Naja. So etwa. Obwohl: die Unir-Karlsruge ist gewissermassen ihr eigener Provider. Du kannst vielleicht erahnen, daß das andere Ende der Beispielsverbindung, das war ichg - zu dem Teitpunkt mit Arcor im Netzwar.
Wenn ja, was bringt mir das,
wenn ich das weiß?
Gute Frage. traceroute ist ein Netzwerkdiagnoseprogramm, was man auch zum Spielen oder Providerraten nutzen kann. Sieh es so…
Doku?
TRACEROUTE(8) System Manager's Manual TRACEROUTE(8)
NAME
traceroute - print the route packets take to network host
SYNOPSIS
traceroute [-l] [-m max\_ttl] [-n] [-p port] [-q nqueries] [-r]
[-s src\_addr] [-t tos] [-w waittime] host [packetsize]
DESCRIPTION
The Internet is a large and complex aggregation of network hardware, con
nected together by gateways. Tracking the route one's packets follow (or
finding the miscreant gateway that's discarding your packets) can be dif
ficult. Traceroute utilizes the IP protocol `time to live' field and at
tempts to elicit an ICMP TIME\_EXCEEDED response from each gateway along
the path to some host.
The only mandatory parameter is the destination host name or IP number.
The default probe datagram length is 38 bytes, but this may be increased
by specifying a packet size (in bytes) after the destination host name.
Other options are:
-l Display the ttl value of the returned packet. This is useful for
checking for assymetric routing.
-m max\_ttl
Set the max time-to-live (max number of hops) used in outgoing
probe packets. The default is 30 hops (the same default used for
TCP connections).
-n Print hop addresses numerically rather than symbolically and nu
merically (saves a nameserver address-to-name lookup for each
gateway found on the path).
-p port
Set the base UDP port number used in probes (default is 33434).
Traceroute hopes that nothing is listening on UDP ports base to
base+nhops-1 at the destination host (so an ICMP PORT\_UNREACHABLE
message will be returned to terminate the route tracing). If
something is listening on a port in the default range, this op
tion can be used to pick an unused port range.
-q nqueries
Set the number of probes per ``ttl'' to nqueries (default is
three probes).
-r Bypass the normal routing tables and send directly to a host on
an attached network. If the host is not on a directly-attached
network, an error is returned. This option can be used to ping a
local host through an interface that has no route through it
(e.g., after the interface was dropped by routed(8)).
-s src\_addr
Use the following IP address (which must be given as an IP num
ber, not a hostname) as the source address in outgoing probe
packets. On hosts with more than one IP address, this option can
be used to force the source address to be something other than
the IP address of the interface the probe packet is sent on. If
the IP address is not one of this machine's interface addresses,
an error is returned and nothing is sent.
-t tos Set the type-of-service in probe packets to the following value
(default zero). The value must be a decimal integer in the range
0 to 255. This option can be used to see if different types-of-
service result in different paths. (If you are not running a
4.3BSD-Tahoe or later system, this may be academic since the nor
mal network services like telnet and ftp don't let you control
the TOS). Not all values of TOS are legal or meaningful - see the
IP spec for definitions. Useful values are probably `-t 16' (low
delay) and `-t 8' (high throughput).
-v Verbose output. Received ICMP packets other than TIME\_EXCEEDED
and UNREACHABLEs are listed.
-w Set the time (in seconds) to wait for a response to a probe (de
fault 3 sec.).
This program attempts to trace the route an IP packet would follow to
some internet host by launching UDP probe packets with a small ttl (time
to live) then listening for an ICMP "time exceeded" reply from a gateway.
We start our probes with a ttl of one and increase by one until we get an
ICMP "port unreachable" (which means we got to "host") or hit a max
(which defaults to 30 hops & can be changed with the -m flag). Three
probes (changed with -q flag) are sent at each ttl setting and a line is
printed showing the ttl, address of the gateway and round trip time of
each probe. If the probe answers come from different gateways, the ad
dress of each responding system will be printed. If there is no response
within a 3 sec. timeout interval (changed with the -w flag), a "\*" is
printed for that probe.
We don't want the destination host to process the UDP probe packets so
the destination port is set to an unlikely value (if some clod on the
destination is using that value, it can be changed with the -p flag).
A sample use and output might be:
[yak 71]% traceroute nis.nsf.net.
traceroute to nis.nsf.net (35.1.1.48), 30 hops max, 56 byte packet
1 helios.ee.lbl.gov (128.3.112.1) 19 ms 19 ms 0 ms
2 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms
3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 39 ms 19 ms
4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 39 ms 40 ms 39 ms
5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 39 ms 39 ms 39 ms
6 128.32.197.4 (128.32.197.4) 40 ms 59 ms 59 ms
7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 59 ms
8 129.140.70.13 (129.140.70.13) 99 ms 99 ms 80 ms
9 129.140.71.6 (129.140.71.6) 139 ms 239 ms 319 ms
10 129.140.81.7 (129.140.81.7) 220 ms 199 ms 199 ms
11 nic.merit.edu (35.1.1.48) 239 ms 239 ms 239 ms
Note that lines 2 & 3 are the same. This is due to a buggy kernel on the
2nd hop system - lbl-csam.arpa - that forwards packets with a zero ttl (a
bug in the distributed version of 4.3 BSD). Note that you have to guess
what path the packets are taking cross-country since the NSFNet (129.140)
doesn't supply address-to-name translations for its NSSes.
A more interesting example is:
[yak 72]% traceroute allspice.lcs.mit.edu.
traceroute to allspice.lcs.mit.edu (18.26.0.115), 30 hops max
1 helios.ee.lbl.gov (128.3.112.1) 0 ms 0 ms 0 ms
2 lilac-dmc.Berkeley.EDU (128.32.216.1) 19 ms 19 ms 19 ms
3 lilac-dmc.Berkeley.EDU (128.32.216.1) 39 ms 19 ms 19 ms
4 ccngw-ner-cc.Berkeley.EDU (128.32.136.23) 19 ms 39 ms 39 ms
5 ccn-nerif22.Berkeley.EDU (128.32.168.22) 20 ms 39 ms 39 ms
6 128.32.197.4 (128.32.197.4) 59 ms 119 ms 39 ms
7 131.119.2.5 (131.119.2.5) 59 ms 59 ms 39 ms
8 129.140.70.13 (129.140.70.13) 80 ms 79 ms 99 ms
9 129.140.71.6 (129.140.71.6) 139 ms 139 ms 159 ms
10 129.140.81.7 (129.140.81.7) 199 ms 180 ms 300 ms
11 129.140.72.17 (129.140.72.17) 300 ms 239 ms 239 ms
12 \* \* \*
13 128.121.54.72 (128.121.54.72) 259 ms 499 ms 279 ms
14 \* \* \*
15 \* \* \*
16 \* \* \*
17 \* \* \*
18 ALLSPICE.LCS.MIT.EDU (18.26.0.115) 339 ms 279 ms 279 ms
Note that the gateways 12, 14, 15, 16 & 17 hops away either don't send
ICMP "time exceeded" messages or send them with a ttl too small to reach
us. 14 - 17 are running the MIT C Gateway code that doesn't send "time
exceeded"s. God only knows what's going on with 12.
The silent gateway 12 in the above may be the result of a bug in the
4.[23] BSD network code (and its derivatives): 4.x (x