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Questions tagged [ping]

For questions about Packet INternet Groper [PING].

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50
votes
4answers
263k views

PING port number?

Yesterday interviewer ask me what is port number for ping and which protocol ping use TCP/UDP. After interview I search on internet and found different different results someone says ICMP uses Port 7,...
21
votes
7answers
7k views

Why can I traceroute to this IP address, but not ping?

I have an IP address and can traceroute to it, but I can not ping. You see, I can traceroute 43.224.226.50: dele-MBP:~ ll$ traceroute 43.224.226.50 traceroute to 43.224.226.50 (43.224.226.50), 64 ...
12
votes
2answers
14k 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 ...
11
votes
4answers
33k views

Interpreting TTL in ping results

I work for a VoIP service provider and I am working an issue with a customer who has a cable internet connection that's throwing me for a loop. He has a single block, which we'll pretend is 70.141.15....
10
votes
2answers
2k views

Why can't I ping from one computer to another using L3 cisco 3550 switch?

I have configured my 3550 L3 switch to redirect HTTP traffic to a significant Machine: This is my scenario ( PCs instead of Routers): This is the switch configuration: CAT3550# show running-config ...
9
votes
2answers
2k views

Where is Ping's “round-trip time” stored in the IP header?

If we use ICMP's ping, we know the TTL and round-trip time are stored in the IP header. In the below IP header map we know TTL's location, but where is the round-trip time? Is it stored in Options?
8
votes
2answers
8k 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 ...
6
votes
2answers
4k views

What would happen to Ping if two PCs have same IP address with same Subnet Mask on same network?

If there are two PCs with same IP address on a LAN, what would happen if I ping that IP address from another PC on the same network and why?
6
votes
1answer
1k views

Why can I ping IP addresses from 127.0.0.1 to 127.255.255.254?

I thought that the loopback IP address of my machine is 127.0.0.1. I do not understand why am I able to ping IP addresses until 127.255.255.254.
5
votes
3answers
685 views

Understanding hubs and switches

Newbie here. I'm trying to understand how hubs and switches work. I read that hubs only forwards to all ports but a switch only forwards to the port it needs to. So, If I connect 3 computers to the ...
5
votes
5answers
2k views

Why can't two hosts (in two different logical networks) connected to each other through cross-over cable communicate?

Let us say, i have two computers (hosts) A and B. Where A has been assigned an IP address of 192.168.1.10/24 and host B has been assigned an IP address of 192.168.2.11/24. And both of them has been ...
5
votes
1answer
360 views

which host will reply to the ping?

suppose having a LAN which contains : FTP server (10.0.0.1) HTTP server (10.0.0.2) SSH server (10.0.0.3) the LAN use NAT overloading and it has a single public IP (1.2.3.4), now if I ping on 1.2.3.4 ...
5
votes
1answer
433 views

Pinging across different subnets? This shouldn't work but it does

I have two computers: PC1 and PC2. PC1 has an IP address of 10.0.0.1/30, and PC2 has an IP address of 10.0.0.6/30. They are connected directly to each other with a crossover cable. My understanding is ...
5
votes
1answer
197 views

How are ping times computed

I have been graphing ping (IPV4) responses times/vs packet size. I was expecting to see a discontinuity of around 2*MTU/BandWidth in response time around the MTU boundary (actually, around 1464 byte, ...
4
votes
2answers
39k views

Difference between ping timed out and destination host unreachable

I'm pinging from a Windows Box to a device that I rebooted. PS C:\Users\administrador> ping 192.168.2.10 Pinging 192.168.2.10 with 32 bytes of data: Control-C PS C:\Users\administrador> ping -...
4
votes
1answer
13k views

What is first? ARP vs ICMP

I want to know what is first after STP. There are just three devices, switch and two hosts. A switch is not configurated and two hosts have each IP by static. Of course, two hosts are connected to ...
4
votes
2answers
743 views

does the DSL distance really add more latency

I've been using dsl internet for quite a while and having a ping from Algeria to France of about 90 ms , after trying to ping some locations in Algeria , i am getting about 50 ms, ping to my gateway ...
4
votes
4answers
2k views

ARP table does not store devices responding to a broadcasted ping request

I have got a simple question, I am doing a broadcasted ping request on my local network, using a Mac with the latest Yosemite 10.10.4. So I ping 255.255.255.255, I get responses from a bunch of ...
4
votes
3answers
612 views

Why I cant Ping An Address across my a routed link

I have two layer 3 switches (Main And back up) and a palo alto firewall main switch connects to the firewall with a routed link port(gi1/1 ip add 10.1.70.2)- firewall (10.1.70.1). All connectivity is ...
4
votes
3answers
506 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 ...
4
votes
1answer
197 views

Strange ping over frame-relay network

Buffing up on Frame-Relay for testing EIGRP nuances over FR for CCNP - topology and relevant show command output here: http://imgur.com/a/Ch6Sh#0 Relevant PVC is between DLCI 103/301 (R1/R4) Why ...
4
votes
1answer
692 views

Cisco Router Setup 1841

I need some help. I am new to using Cisco routers (as far as setting them up my self), so forgive me if this is something simple that I am over looking or not understanding. I have a cable internet ...
4
votes
1answer
5k views

Why we can not ping to multicast address 224.0.0.9 of RIP

We know that RIP v2 uses multicast address 224.0.0.9 for periodic broadcast of routing table. So it means that every router configured with RIP V2 is monitoring for any packet with destination address ...
4
votes
1answer
3k views

Cisco 3725 - ping encapsulation failed

I am unable to ping from R1 to R2. debug ip packet detail returns IP: s=172.16.12.1 (local), d=172.16.12.2 (FastEthernet0/0.12), len 100, encapsulation failed. I understand this means it can't resolve ...
4
votes
1answer
277 views

Latency in P2P Circuit

I have one P2P Circuit from our HQ to a secondary office. the distance between them is approx 2kms. Earlier when the Circuit was delivered at that time we were having an RTT of 3-4ms. It is a 10Mbps ...
3
votes
4answers
5k views

When a ping is lost, what happens?

Suppose that the message you are sending does not reach the destination, such as a ping. Is the content of that message protected? How is a retransmission accomplished?
3
votes
3answers
22k views

Ping a private IP address in another network

We all know that PCs on a LAN use private IP addresses such as 192.168.2.3, etc. Now my question is, how can a PC say mine having a private address of 192.168.2.3 communicate with other LAN PC ...
3
votes
2answers
52k views

dont fragment bit PING TOOL

Actually my machine wwan0 MTU is 1500 ashokkrishna@ashokkrishna-Lenovo-B560:~$ ping -s 1490 example.com PING example.com (93.184.216.119) 1490(1518) bytes of data. 1498 bytes from 93.184.216.119: ...
3
votes
2answers
2k views

Strange router's MAC address from ICMP Echo Reply?

Using Wireshark to capture ICMP packets (Windows) using ping to google.com, I can see the source-MACAddr of the ICMP Echo replies is not the same as the MAC address of my direct router (which is the ...
3
votes
2answers
832 views

Why I have higher ping to the VLAN interface than to other local interfaces

I wouldn't call it an issue, but I'm curious. On our Quanta switch we have a couple of VLANs and vlan interfaces accordingly. Let's say I'm on a computer in VLAN 10, if I do: ping 192.168.10.1 ...
3
votes
4answers
19k views

Cant ping across router?

I am trying to set up communication across a network, and I have run into a bit of a problem. In the diagram below, why is it that I cannot ping host 2 from host 1? Router 1 has interfaces on both ...
3
votes
2answers
2k views

Cannot ping subinterfaces on Cisco ASA 5508

I am not able to ping the inside subinterface on my ASA 5508-x. When setup this way, I am able to ping the interface: interface GigabitEthernet1/3 nameif inside security-level 100 ip address X.X....
3
votes
1answer
230 views

Can't ping the management IP of Switch

My topology is: I am logged in to R1. I can ping 10.0.0.2 on R2 and 198.51.100.1 on R2, but can't ping the management IP of sw3 (198.51.100.2). What am I doing wrong? R1#sh ip arp Protocol Address ...
3
votes
2answers
68 views

are the RTTs additive?

By using the ping, I calculate the RTT between A and B. I calculate the RTT between A and C. I calculate the RTT between C and B. Is it possible to compare the RTT of topological link A->B with the ...
3
votes
2answers
252 views

Data-packets, sent to a router, are treated differently based on their origin: clarification needed

On a Cisco Packet Tracer sample e2-232, there is something I don't understand, even after following the step-by-step instructions on the sample project.The logical topology is shown in the following ...
3
votes
2answers
7k views

ping in pure layer 2 LAN [closed]

How can I ping a specific IP on a network which only contain switches while switches as far as I know don't understand IPs but only MAC!
3
votes
1answer
24k views

linux ping mtu and fragmentation

I've been experimenting with the ping utility on Linux. I set a mtu of 500 bytes on my router. Now, when I ping to an external host, I get the following output: ping -c 3 -s 1300 10.0.2.1 ...
3
votes
2answers
365 views

Why R1 is not reachable to R3?

I didn't configure any routing protocol to any of the router and tried to apply static routes in order to get out of the network and I've configured static routing in a manner that if R1 sends a ping ...
3
votes
4answers
5k 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
542 views

ping reply arp table

I have created a simple topology with routers and computers and I ping from computer A to computer B . Firstly, computer A send ARP request to gateway of A and then got reply. Mac and ip of gateway is ...
3
votes
1answer
898 views

What Does ICMP Code 9 Mean For a Type 8 Packet?

I am currently doing an assignment that requires us to generate ICMP packet with various types and codes. I have consulted the RFCs as well as various other place. Many of the types and codes I get ...
3
votes
1answer
98 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
2answers
5k views

Ethernet padding

I'm using Wireshark for my project. I sent a ping over to Google.com and Wireshark said that the length was 57 bytes(when I received the reply it was 60 bytes long and it contained 6 bits of padding. ...
3
votes
3answers
1k views

Configuring ASA: I can browse out, but no incoming traffic?

I can't seem to get this code working. I'm not well versed in ASA setups, but there seems to be an increase in popularity around here for them, and word gets out that if you can work on one, you're ...
3
votes
2answers
4k views

Computer unable to ping another over two routers

I am using Cisco Packet Tracer to simulate a network of two routers each connected to a switch and two hosts per switch. The network is setup as so: I'm using a default subnet mask of 255.255.255.0. ...
3
votes
1answer
576 views

Ping unlocks ipsec vpn

I have a ipsec vpn with a foreign company, this connects my network with their network and they have a different ip subnet. Ipsec is made by a pfsense gateway/firewall. I'm sure it is well configured,...
3
votes
2answers
786 views

OSPF can't ping other network segments

I'm trying to setup a very simple OSPF network with Vyatta. From the best of my knowledge they let all traffic in by default, and I haven't set any firewall rules. The vyatta instances are launched as ...
3
votes
2answers
679 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 ...
3
votes
1answer
4k views

Cisco Switch Can't Ping Attached Device

PC1-VLAN1======Switch : Successful pings from the switch PC1-VLAN2======Switch : *Unsuccessful* pings from the switch I've got a single switch with a static IP directly connected to PC1 with a static ...
3
votes
2answers
957 views

Disable ping replies on brocade switch

What is the command to use to disable ping replies from a brocade switch? Baasically, I am trying to disable any outbound ping messages to inbound ICMP request messages. I stumbled upon brocade-...