Traceroute command is a network diagnostic tool for displaying the route packets take to network host or destination. It shows how long each hop will takes and how many hops that the packet requires to reach the specify destination. In linux, traceroute command is used while in windows and dos environment, they used tracert command. In this post i will show you how to install and how to use traceroute command to diagnose your IP network related issues. This steps has been tested on RHEL 6/7, CentOS 6/7 and Oracle Linux 6/7.
1. If your linux VPS or dedicated server does not installed with traceroute, it will return this warning :
# traceroute www.google.com -bash: traceroute: command not found
Or you can verify the traceroute install or not by issue which command :
# which traceroute /usr/bin/which: no traceroute in (/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin)
2. To install traceroute, run the following command :
# yum install traceroute -y
3. Verify the command install or not :
# which traceroute /bin/traceroute
4. How to use traceroute command :
a. Find the network path from my centos6 server to google.com :
# traceroute [options]
Example :
# traceroute www.google.com traceroute to www.google.com (58.27.108.153), 30 hops max, 60 byte packets 1 192.168.2.1 (192.168.2.1) 9.233 ms 9.020 ms 8.857 ms 2 219.93.218.177 (219.93.218.177) 20.717 ms 20.529 ms 27.526 ms 3 60.49.55.93 (60.49.55.93) 57.368 ms 57.446 ms 57.187 ms 4 10.55.32.58 (10.55.32.58) 76.846 ms 10.55.32.56 (10.55.32.56) 66.418 ms 66.906 ms 5 58.27.105.125 (58.27.105.125) 75.779 ms 65.556 ms 65.592 ms 6 * * * 7 * * * 8 * * * 9 * * * 10 * * * 11 * * * 12 * * * 13 * * * 14 * * * 15 * * * 16 * * * 17 * * * 18 * * * 19 * * * 20 * * * 21 * * * 22 * * * 23 * * * 24 * * * 25 * * * 26 * * * 27 * * * 28 * * * 29 * * * 30 * * *
1 is the internet gateway on the network this traceroute was done (ADSL modem local IP)
2 is the ISP the origin computer is connected to.
My PPPoE modem WAN IP details :
b. Find the network path from my centos6 server to google.com and do not resolve IP addresses to their domain names :
# traceroute www.google.com -n
c. Find the network path from my centos6 server to google.com and set the number of seconds to wait for response to a probe to 0.1 seconds (Default is 5.0) :
# traceroute www.google.com -w 0.1
d. Find the network path from my centos6 server to google.com and set the number of probes per each hop to 5 (Default is 3) :
# traceroute www.google.com -q 5
5. Display basic command line options help for more usage :
# traceroute --help
Usage:
traceroute [ -46dFITnreAUV ] [ -f first_ttl ] [ -g gate,... ] [ -i device ] [ -m max_ttl ] [ -N squeries ] [ -p port ] [ -t tos ] [ -l flow_label ] [ -w waittime ] [ -q nqueries ] [ -s src_addr ] [ -z sendwait ] host [ packetlen ]
Options:
-4 Use IPv4
-6 Use IPv6
-d --debug Enable socket level debugging
-F --dont-fragment Do not fragment packets
-f first_ttl --first=first_ttl
Start from the first_ttl hop (instead from 1)
-g gate,... --gateway=gate,...
Route packets through the specified gateway
(maximum 8 for IPv4 and 127 for IPv6)
-I --icmp Use ICMP ECHO for tracerouting
-T --tcp Use TCP SYN for tracerouting
-i device --interface=device
Specify a network interface to operate with
-m max_ttl --max-hops=max_ttl
Set the max number of hops (max TTL to be
reached). Default is 30
-N squeries --sim-queries=squeries
Set the number of probes to be tried
simultaneously (default is 16)
-n Do not resolve IP addresses to their domain names
-p port --port=port Set the destination port to use. It is either
initial udp port value for "default" method
(incremented by each probe, default is 33434), or
initial seq for "icmp" (incremented as well,
default from 1), or some constant destination
port for other methods (with default of 80 for
"tcp", 53 for "udp", etc.)
-t tos --tos=tos Set the TOS (IPv4 type of service) or TC (IPv6
traffic class) value for outgoing packets
-l flow_label --flowlabel=flow_label
Use specified flow_label for IPv6 packets
-w waittime --wait=waittime
Set the number of seconds to wait for response to
a probe (default is 5.0). Non-integer (float
point) values allowed too
-q nqueries --queries=nqueries
Set the number of probes per each hop. Default is
3
-r Bypass the normal routing and send directly to a
host on an attached network
-s src_addr --source=src_addr
Use source src_addr for outgoing packets
-z sendwait --sendwait=sendwait
Minimal time interval between probes (default 0).
If the value is more than 10, then it specifies a
number in milliseconds, else it is a number of
seconds (float point values allowed too)
-e --extensions Show ICMP extensions (if present), including MPLS
-A --as-path-lookups Perform AS path lookups in routing registries and
print results directly after the corresponding
addresses
-M name --module=name Use specified module (either builtin or external)
for traceroute operations. Most methods have
their shortcuts (`-I' means `-M icmp' etc.)
-O OPTS,... --options=OPTS,...
Use module-specific option OPTS for the
traceroute module. Several OPTS allowed,
separated by comma. If OPTS is "help", print info
about available options
--sport=num Use source port num for outgoing packets. Implies
`-N 1'
-U --udp Use UDP to particular port for tracerouting
(instead of increasing the port per each probe),
default port is 53
-UL Use UDPLITE for tracerouting (default dest port
is 53)
-P prot --protocol=prot Use raw packet of protocol prot for tracerouting
--mtu Discover MTU along the path being traced. Implies
`-F -N 1'
--back Guess the number of hops in the backward path and
print if it differs
-V --version Print version info and exit
--help Read this help and exit
Arguments:
+ host The host to traceroute to
packetlen The full packet length (default is the length of an IP
header plus 40). Can be ignored or increased to a minimal
allowed value
