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Questions tagged [traceroute]

For questions about trace routing where, for instance, you are troubleshooting routing issues or have problems using the traceroute command via CLI on a network device.

17
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1answer
2k views

Why do some common traceroute implementations default to using UDP probes?

I was recently troubleshooting a network connectivity meta-problem, in that I knew a given destination was reachable, but I was not able to demonstrate that with traceroute because the path went cold ...
15
votes
2answers
23k views

Traceroute - every packet has TTL == 1

I'm working on Wireshark lab-IP in Computer networking - A top down approach and I don't understand why every packet that normally expired has a TTL of 1. Here is my Wireshark capture file. https://...
11
votes
2answers
48k views

Difference between unresponsive (*) and unreachable (!H) hosts in traceroute output

When running traceroutes some hops return * which as far as I know means that the host is not responding to ICMP echo request, and some other hops (mainly the last) return !H which according to the ...
11
votes
2answers
13k views

traceroute many hops with the same ip

I'm a software developer that sometimes has to do some easy network tasks but knows almost nothing about it. I'm having some problems with a vps I rent ( ENJOY VPS: Unmanaged VPS - Medium VPS) and ...
6
votes
5answers
2k views

traceroute doesn't print entire route sometimes

Monitoring my network I realized some time ago that traceroute used to print routes more complete than it is doing right now... and, right now, sometimes traceroute omits some devices. For example, ...
6
votes
3answers
6k views

Tips on analyzing traceroute readings

I'm pretty new to networking and I'm currently playing about with the traceroute command on the Windows command line. Do you happen to have any tips/know any resources that are helpful in learning how ...
5
votes
3answers
14k views

Traceroute Over TCP vs UDP

For what purpose would one wish to send traceroute over TCP rather than UDP? What advantages/disadvantages are there in doing so? I know that traceroute normally uses UDP ICMP "echo" packets while ...
5
votes
2answers
358 views

Why there are ip(ip) and domain(ip) 's difference and multi rows records in the traceroute?

In the traceroute command: $ traceroute 104.43.54.2 traceroute to 104.43.54.2 (104.43.54.2), 64 hops max, 52 byte packets 1 10.10.10.1 (10.10.10.1) 4.852 ms 4.623 ms 1.588 ms 2 100.64.0.1 (100....
5
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2answers
839 views

IP Traceroute RFC 1393

Is RFC 1393 implemented by real routers in practice? Are there any tools that generate traceroutes using it?
5
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2answers
7k views

How to trace outgoing interfaces?

The Unix command traceroute traces the IP addresses of the nodes from a source node to a destination node. Every node in between has an incoming and an outgoing interface. Executing traceroute -n dst ...
5
votes
2answers
2k views

Route does not work / LAN port not reachable

Current Network I have the following network situation: Internet | 81.x.x.x (WAN) Modem / DSL Router 1 192.168.1.1 (LAN) | +-----------------------------+ | ...
4
votes
1answer
1k views

difference between reverse, forwarding and return path on traceroute

As described on the title, I can't make difference between reverse, forwarding and return path, especially between reverse and return path. Also, how the RTT is affected by the reverse, forwarding ...
4
votes
1answer
503 views

Does traceroute show the IP address of the entry port? or exit port?

Does traceroute show the IP address of the entry port? or exit port? For example, if there is an intermediary router in the path with 198.28.56.18 facing the source (entry port), and 65.86.24.136 ...
4
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2answers
1k views

traceroute -A - how does the lookup work?

How does the traceroute -A command work? How does the program look up the ASN? On which protocols or databases does the query depend? Can I recreate the -A option? I am using this version: Modern ...
3
votes
1answer
246 views

Slower hops in traceroute

What are the main reasons why some routers that appear in the traceroute output have a greater round trip time?
3
votes
3answers
127 views

Is it possible to perform a Layer 2 (MAC address) traceroute?

I understand the difference between layer2 & layer3 and MAC & IP. I understand address resolution protocol, etc. But is there any way to do a traceroute that will show Layer 2 information? For ...
3
votes
1answer
1k views

Traceroute UDP port question

I know, that traceroute uses UDP, and for destination port it starts with 33434. Then, with each next hop it increments the destination port number by 1. The questions is: why does traceroute need to ...
3
votes
3answers
170 views

Basic (probably) question on traceroute

I was trying to do tracert, and instead of getting ip addresses like I'm used to, all I see is this (below). Can anyone tell me what is going on? There are no spaces in the command, I just can't post ...
3
votes
2answers
64 views

Why does ip routing not take an even remotely direct route?

I ran a traceroute on a url to a server we own in New York. I'm in central Florida. Traceroute showed the request being directed to west Florida and then far south Florida before finally being ...
3
votes
1answer
204 views

how to implement traceroute without using TTL?

how to implement traceroute without using TTL? This is an interview question. We all knew Traceroute uses TTL to get the routing path. The question is how to implement traceroute without using TTL. ...
3
votes
4answers
4k views

Are ping-times directly related to location/distance?

Suppose I want to determine if an IP is located in my country, without a third-party servvice. Could I estimate that to a certain degree by measuring ping times? Or is it better to look at the number ...
3
votes
1answer
79 views

Same hop appears 4 times on a traceroute [closed]

When I traceroute bbc.co.uk in my home Network the first hop appears 4 times. What could be causing this ? @Latitude-7480 ~ $ tracepath bbc.co.uk 1?: [LOCALHOST] ...
3
votes
3answers
450 views

Cannot access certain web page. Ping succeded traceroute didn't

This is my first question on forums at all. I work as a network support engineer and I have a little issue at work and I would really appreciate advice from you. Cannot access the url www.reach2.org ...
3
votes
2answers
608 views

ping, traceroute not working [closed]

I was going through a Networking course online and they instructed me to try ping and traceroute commands on Linux for network checking. I have Fedora OS v22 and am using WLAN Dlink Router for ...
2
votes
2answers
216 views

Why traceroute is still Used?

currenty I'm reading an article about 'Paris traceroute' , as i understood The Classical Traceroute give inexact information about the path that a packet traverse , 'incorrect links , missed nodes '....
2
votes
3answers
772 views

Private IP inside internet?

Firstly sorry if this question has already been asked. While playing with traceroute, I came across something really strange... traceroute to 185.75.143.25 gives: - 10.214.255.254 - 10.255.255.254 ...
2
votes
1answer
326 views

If traceroute fails why does ping still work?

If I can ping a router successfully, why is it that when I do traceroute, it stops at a particular interface and says "ICMP type:3, code:3, Destination port unreachable". Doesn't that mean that it can'...
2
votes
1answer
167 views

Traceroute of Router's own serial port

I got two routers on my network and I am pinging one router's serial port ip address from that router itself. by checking traceroute I found ping is going outside to neighbor router which is directly ...
2
votes
2answers
400 views

different between “show ip bgp” command and traceroute

base on following results from route-views ------------------------------------------------------------------------------------------------------------------------------------------------------------...
2
votes
1answer
389 views

What is the significance of number or probes in traceroute?

I am aware that -p sets the number of probes in a traceroute. I recently did the following traceroute with different values of -p i.e 1 and 3 (the default value). Can you explain the increase in the ...
2
votes
1answer
378 views

TCP Traceroute with actual TCP session [closed]

Has anyone ever found a tool that performs a TCP traceroute with an actual established TCP session? I can launch a server/client on each end, if required. tcptraceroute & mtr aren't candidates ...
2
votes
2answers
2k views

Difference in number of hops in Traceroute

I was experimenting with some of the network monitoring commands in cmd and I noticed that there's a significant difference in the number of hops in the output of tracert for different hosts. For ...
2
votes
2answers
2k views

trace route result same hop but different destination ip

I do traceroute in my router and I found result like this traceroute to 114.0.36.130, 30 hops max, 40 byte packets 1 114.0.17.30 (114.0.17.30) 3.49 ms 14.2 ms 2.65 ms 2 114.0.27.1 (...
2
votes
1answer
174 views

Traceroute for http sites endless loop

I used following command - traceroute -m 255 www.bbc.com and result is an endless loop. I also tried on some other http sites, same result. I also used online traceroute service like monitis which ...
2
votes
2answers
733 views

Trace Route RTO in one hop but next hop works

Today when I was doing tracert, in the 6th Hop I get RTO but my next hop seems to be reachable. How come it works? 6 * * * Request Timed Out 7 58ms 58ms ...
2
votes
2answers
89 views

Why do the same websites get routed in two widely different paths?

Depending on the time, when I open a website and do a traceroute, I notice that website goes to a different path than the usual, and some websites just never open. Why the same network alternate ...
1
vote
3answers
72 views

Whether the traceroute command only can check “to” path, can not check “back” path?

How to detect the router path of traffic? I use the ipip.net for ICMP traffic: I want to check the out path and back path. such as I have A address 60.248.41.135 and B address 103.248.41.135. ...
1
vote
2answers
298 views

Why there is only one hop in the tracert?

I use the tracert to a remote server IP address: C:\Users\lll>tracert 103.224.19.11 Track by up to 30 hops The route to f1.FF-SALE.COM [103.224.19.11]:    1 44 ms 44 ms 44 ms f1.FF-SALE.COM [103....
1
vote
1answer
26 views

how does Trace route packet work

I am fining difficulties understanding trace route command how does trace route works from source to a destination? how the routers reply to the source with their IP? thank you
1
vote
1answer
63 views

Why there still need a parenthesis contains it again in traceroute logs?

I traceroute to 104.210.32.76: Traceroute Starting… traceroute to 104.210.32.76 (104.210.32.76), 64 hops max, 72 byte packets 1 10.10.10.1 (10.10.10.1) 25.326 ms 1.344 ms 1.135 ms 2 100.64.0....
1
vote
1answer
48 views

Are traceroute hop latency measurements relative to the previous hop or to the origin?

With traceroute output of this: traceroute to google.com (216.58.223.14), 64 hops max, 52 byte packets 1 192.168.119.1 (192.168.119.1) 1.321 ms 0.980 ms 0.936 ms 2 rtr3-c16-dc1.macrolan.co.za (...
1
vote
3answers
272 views

Traceroute inside a per packet load balancing based infrastructure

Could you confirm that in an infrastructure configured with "per packet" load balancing on the Routers (same route same metric), the usage of traceroute become unusable ? In this case the ...
1
vote
2answers
633 views

Traceroute only showing private layer3 hops and then direct end destination

I am doing a traceroute to salesforce.com, google.com and I see all the layer hops to my Firewall and then one hop to final destination- which is incorrect. I am not seeing any of the intermediate ...
1
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3answers
422 views

Windows implementation of traceroute (tracert)

Unlike it's Unix/Linux counterpart, the Windows tracert software doesn't seem to have flags to switch between ICMP and UDP. Does anyone know for certain which it uses? I am having trouble with two ...
1
vote
2answers
3k views

Preventing a Cisco router from appearing in a traceroute

I am trying to prevent a Cisco 2911 router's IP address from appearing in an inbound traceroute. I have configured the line: no ip unreachables on the Internet-facing interface, and while this ...
1
vote
1answer
129 views

Does the TTL decrease over a crossover cable?

I have a little embedded device directly connected to a laptop via a crossover cable. I'm monitoring the traffic between the two using Wireshark and I witness a TTL of 30 for TCP packets coming from ...
1
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2answers
64 views

Explanation of traceroute

Can anyone help me to explain the results of this traceroute. Why on hop 2 will latency suddenly increase? and decreases at hop 3 and will rise significantly to hop to 8.
1
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1answer
192 views

How would you map a network at layer 2 without CDP or LLDP?

I'm on an ASA right now and can path my directly connected next hop devices via IP address, but I want to make sure there isn't a switch in between. Another related question, when I "show arp" it ...
1
vote
1answer
60 views

cisco network meanings and traceroute

I have a small network here. The connection from router 1 to router 3 is relevant. I have two questions in one. On the one hand I would be interested, why at Cisco between the routers always this red ...
1
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2answers
422 views

Traceroute to another interface of a router

When I try to traceroute to a remote server, I found that most likely the first router interface where the packet arrives responds to traceroute. Is it possible to ask another interface of the router ...