Ping is a mechanism to see if a remote host is reachable via an IP network

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324
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18answers
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Ping a Specific Port

Just a quick sanity check here. Can you ping a specific port of a machine, and if so, can you provide an example? I'm looking for something like ping ip address portNum.
78
votes
13answers
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Is Ping a reliable way to check if a server is available?

In my application I am pinging a server and waiting for a response. I am using this to determine whether the server is available and responsive or not. Is this a reliable way of determining ...
45
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8answers
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What does “TTL expired in transit” mean on a ping attempt?

We get the message “TTL expired in transit” when we try to ping to a server in a different network segment. When we run tracert, 4 ip addresses repeat themselves indefinitely: 14 60 ms 59 ms ...
34
votes
5answers
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Why do we ping the IP 4.2.2.2 to test connectivity?

For as long as I can remember, I've always used the IP 4.2.2.2 when testing network connectivity using ping. What is significant about this IP, and when did this practice start?
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9answers
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How to ping in linux until host is known?

How can I ping a certain address and when found, stop pinging. I want to use it in a bash script, so when the host is starting up, the script keeps on pinging and from the moment the host is ...
20
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2answers
2k views

Pinging an IP address responds with different IP

When I try to ping the IP address 10.10.208.57 I have no response since nothing exist in the network with that IP address. However if I try to ping 10.10.208.057 instead another IP address responds: ...
19
votes
3answers
18k views

What does mdev mean in ping(8)?

What does mdev mean in ping output (last row below)? me@callisto ~ % ping -c 1 example.org PING example.org (192.0.43.10) 56(84) bytes of data. 64 bytes from 43-10.any.icann.org (192.0.43.10): ...
18
votes
7answers
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Enable Ping in Windows Server Firewall?

I've just installed Windows Server 2008 on a server and I'm able to connect through Remote Desktop but can't ping. Do I need to open an special port on the firewall to be able to ping a server?
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11answers
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Is there any way to ARP ping on Windows?

On Linux and other systems, there is an utility called arping which can be used to send ARP requests ("pings") and show the answers, much like the "ping" utility but using ARP instead of ICMP. Is ...
16
votes
10answers
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How can I set a short timeout with the ping command?

I am trying to write a script that lists all the hosts on my LAN (there a about 20 of them) and writes the ping status next to each host. I have the DHCP leases file, so I have all the IPs (say, 10.0....
15
votes
1answer
69k views

How to stop ping output?

I run ping <hostname> command in console and it now outputs hundreds of those rows now (icmp_seq=526 ttl=64 time=0.026 ms), icmp_seq is like 500 or more now. How to stop it? (linux debian) ...
14
votes
12answers
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Will a higher bandwidth Internet connection lower ping response time?

It sounds obvious that a faster connection lowers latency... But I wonder: I am working remotely on a host the other side of the world - light can only travel so fast (1 foot in a nano second) and we ...
12
votes
3answers
12k views

Why can't I ssh into (or even ping) my Ubuntu VM from the Mac OS X host?

I'm running Ubuntu 8.04 as a virtual machine using VMware Fusion 3.0 on Mac OS X 10.5.8. I want to be able to ssh into my VM from the Mac OS X host (so I can use MacFUSE and SSHFS to mount the VM's ...
12
votes
2answers
4k views

Strange: why does linux respond to ping with ARP request after last ping reply?

I (and a colleague) have just noticed, and tested, that when a Linux machine is pinged, after the last ping it initiates a unicast ARP request to the machine that initiated the ICMP ping. When pinging ...
11
votes
6answers
29k views

How does ping know that my packets are filtered?

I'm customer of an Irish ISP, eircom, which has started censoring the pirate bay. When I try to ping 194.71.107.15 which is the IP address of thepiratebay.com, I get this output: PING 194.71.107.15 (...
11
votes
6answers
8k views

Why does traceroute take much longer than ping?

How to explain this? C:\Documents and Settings\Administrator>tracert google.com Tracing route to google.com [64.233.189.104] over a maximum of 30 hops: 1 <1 ms <1 ms <1 ms ...
10
votes
4answers
11k views

Linux router: ping doesn't route back

I have a Debian box which I'm trying to set up as a router and an Ubuntu box which I'm using as a client. My problem is that when the Ubuntu client tries to ping a server on the Internet, all the ...
9
votes
7answers
7k views

How to disable responses to PING [closed]

I feel like this should be a really simple thing to do, but googling and checking SF I didn't see anything. I'm trying to make my Fedora server not respond to pings, how do I do that?
9
votes
4answers
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Ping replacement that shows real time

Is there a ping replacement that will display the system's date/time in addition to the round trip time and sequence number? I would prefer a tool that runs on Linux, but if there is a cli tool I can ...
9
votes
6answers
15k views

Network latency: 100Mbit vs. 1Gbit

I have a webserver with a current connection of 100Mbit and my provider offers an upgrade to 1Gbit. I understand that this refers to throughput but the larger the packets, the faster they can be ...
8
votes
14answers
23k views

How can I determine if a machine is online without using ping?

I used to use an application that could ping or maybe run a port scan on a machine even if the machine was configured to not allow it. I am currently trying to ping a remote machine on our WAN, but I ...
8
votes
9answers
16k views

OS X: Can't Resolve Windows Machine Names [closed]

I'm running a mixed environment at home and at work. My server machines are Win Vista, and I have a Unibody Macbook Pro running 10.5.7 On my mac, I can ping some home windows by name (If I use the ...
8
votes
3answers
9k views

Find information for local IP address?

We have had a BT engineer visit recently, trying to solve a problem with our IP phone system. One point they made was that we had four DHCP servers running on the network. I have disabled two of them ...
8
votes
2answers
12k views

Data obtained from ping: is it round trip or one way?

I have 2 servers, each in two separate locations. I need to host an application on one, and the database server on the other. From the app server, if I ping the database server, on average I get ...
8
votes
2answers
15k views

DNS can't resolve hostname; nslookup can

I have a user on Windows 7 that is trying to access a local server with a DNS name of windows.cs. We have two internal DNS servers. The DHCP server assigns users the two internal DNS servers as ...
8
votes
4answers
9k views

How does TCP Ping or Traceroute Work?

How does the tcp ping or traceroute work? Does it take in account just the time it takes to establis the TCP handshake? Also in ICMP ping you can specify the packet size, can this be achieved in TCP ...
8
votes
2answers
2k views

Public hosts for ping

For my firewall scripts to determine whether my ISP is up I need a few reliable, geographically distributed addresses to ping. I could just use some major sites like Google, Akamai, etc. But that ...
7
votes
5answers
42k views

Ping “replies” from same computer with 'Destination host unreachable' (no route to other computer)

I've got two computers in a LAN behind a wireless router. One has XP with ip 192.168.1.2 This one has W7 with ip 192.168.1.7 If I try to ping the other one from this computer, I get this: C:\Users\...
7
votes
1answer
20k views

My server is working fine, but I can't ping it

I noticed earlier, one (of many) of our EC2 instances doesn't respond to ping requests. Everything else runs fine, SSH, HTTP, FTP, Database all working perfectly, but ping fails. This instance is ...
7
votes
3answers
10k views

Why can't I ssh or ping my brand new Amazon EC2 instance?

I just created a free EC2 instance with all the defaults. It says it's running in the AWS Management Console. On the "Instance Actions" menu, I click "Connect". I copy the DNS name provided (looks ...
7
votes
2answers
650 views

Why nslookup doesn't use mdns while ping do?

In dnsmasq.conf: address=/local/127.0.0.1 In resolv.conf: # Generated by NetworkManager domain example.com search example.com nameserver 127.0.0.1 nameserver 10.66.127.17 nameserver 10.68.5.26 I ...
6
votes
1answer
415 views

ping with line numbers

Simple question: how to make ping on Linux to show line numbers in output? I mean: 1 64 bytes from www.site.com (2.7.1.1): icmp_req=1 ttl=247 time=17.9 ms 2 64 bytes from www.site.com (2.7.1.1): ...
6
votes
2answers
6k views

Nagios bizare ping behaviour

I have nagios setup as I want it, but last night it started alerting me of a problem pinging the internet. (I have a check that pings www.google.com to test that the internet is still working) Now ...
6
votes
1answer
8k views

IPv6: Can't ping anything - “Operation not permitted”

I've been working on getting IPv6 support into my network, and had everything working properly for a short while. The server is running Ubuntu Server 8.10. Now however whenever I attempt to do ...
6
votes
4answers
22k views

Graphical Ping utility with logging

I need to continuously test the quality of the connection between hosts, and I would like to use ping for that, in order to see WHEN the problem occurs. It should provide LOG of the pinging, with ...
6
votes
3answers
2k views

Why would ping give me fast rtt values, but take a long time for each response to come back?

I've got a bit of a basic networking question here regarding ping. When pinging a particular host on a completely different subnet, I get a response like this: PING myhost.example.com (1.2.3.4) 56(...
6
votes
3answers
6k views

nmap does not find alive hosts with ping scan

I try to ping scan my local network using nmap, but it doesn't seem to find machines that are for sure alive. It responses to ping but on to ping scan. Results for ping: $ ping 192.168.0.2 PING 192....
5
votes
3answers
2k views

Why is ping to Google servers and Google DNS so low?

I noticed that ping to Google DNS and to google.com from Serbia is about 15ms, but google servers are located in California! http://www.geoiptool.com/en/?IP=173.194.39.110 My dedicated server is ...
5
votes
2answers
13k views

how to know who ping my computer ? [duplicate]

Possible Duplicate: How can I know when my computer is pinged? I'm using Linux. I would like to know how to tell who is pinging my computer. I have seen this similar question using Windows, ...
5
votes
3answers
24k views

Ping from specific network adapter on Windows

Hey, I've been troubleshooting network issues on servers with 2 NICs and laptops with wired and wireless cards. How can I force the PING and TELNET to be sent from a specific adapter? I know it's a ...
5
votes
3answers
10k views

Change how Nagios determines if server is offline?

I'm new to nagios and my server is on a network which does not allow the server to be pinged. Is it possible for me to check if the server is up another way? e.g via SSH or HTTP? How would I do this ...
5
votes
2answers
8k views

How can I know when my computer is pinged?

I am trying to find a problem on a local network. I want to be able to know when a specific computer (Windows XP) is pinged. Thanks!
5
votes
2answers
1k views

Faster way to ping URL than curl [closed]

What would be the fastest way to check whether the specified URL is working? (responding in OK http status code)? For now I'm using curl, but I have bunch of URLs to test in a loop, so I'm looking ...
5
votes
2answers
4k views

Cannot ping over LAN until a ping is received

I have two OSX machines on a local subnet. Pings from Machine A to Machine B consistently timeout until Machine B pings Machine A. After B pings A, A can successfully ping B, but this success is ...
5
votes
3answers
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How to Ping explicitly from eth1 instead of eth0

I'm trying to execute a ping with eth1, but the program uses eth0(the default network device). Any tips, tricks, or alternate techniques available?
5
votes
2answers
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Pings from VPN network to VPN client work; pings into from VPN client to VPN network fail - why?

We are in the process of setting up an OpenVPN server for some servers running in a cloud. We are stumped with a connectivity problem whereby the hosts on the VPN server's LAN can ping te VPN client, ...
5
votes
1answer
8k views

Loop redirect when ping my gateway

I have a router with WAN and LAN setup and act as DHCP server/gateway on my local LAN. The IP address is 192.168.1.1. Today, I was hit by an internet failure and I checked the ping and get this ...
5
votes
2answers
6k views

HP Procurve 2920 VLANs with DHCP cannot ping

I have problem setting up working VLANs and DHCP server on HP Procurve 2920. My problem is that I cannot even ping computers between VLANs with static ip addresees. winXP pc on VLAN101 with 192.168.1....
5
votes
1answer
2k views

Ping not working from tap interface attached to bridge interface with ip on same subnet as that of bridge to outside

My requirement is to create a multiple tap interfaces, each with ip address on same subnet. I tried this by creating a bridge br0 (192.168.1.199) ___________|...
4
votes
2answers
5k views

Unable to ping, although can download packages

I've installed Debian Squeeze on a Dell PowerEdge server. However, I'm facing some problem with configuring the network. Although I can ping machines inside my network, I'm unable to d0 so outside the ...