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

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148
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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.
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12answers
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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 ...
28
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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 ...
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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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6answers
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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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8answers
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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 ...
12
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2answers
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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
11answers
17k views

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 ...
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3answers
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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): ...
9
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4answers
958 views

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
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3answers
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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 ...
8
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9answers
15k views

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 ...
8
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6answers
6k 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
6answers
12k views

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, ...
8
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2answers
3k 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
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4answers
4k 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 ...
8
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2answers
1k 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
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9answers
4k views

How To Disable Responses To PING

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 ping, how do I do that?
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8answers
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OS X: Can't Resolve Windows Machine Names

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 ...
7
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5answers
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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: ...
7
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4answers
7k 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 ...
6
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6answers
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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 ...
6
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14answers
9k 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 ...
6
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1answer
344 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): ...
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6answers
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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 ...
5
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3answers
1k 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
1answer
14k 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) ...
5
votes
2answers
439 views

Why do I get search.com instead of “host not found”?

On my VPSs with LeaseWeb, whenever I reach an non-existent host, I get search.com domain name, and if I ping a non-existent domain from SSH, I don't get "host not found" but replies from IPs like ...
5
votes
2answers
120 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 ...
5
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2answers
2k 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 ...
5
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2answers
6k views

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
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1answer
5k 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 ...
5
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2answers
724 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) ...
4
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2answers
2k 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 ...
4
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3answers
3k 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 ...
4
votes
1answer
1k views

What do the RTT numbers mean in a TraceRoute result?

I have this traceroute result, and I am wondering what EXACTLY do the 3 numbers mean at the end of each line? I assume they are ping times, but what exactly is the difference between each number? 1 ...
4
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2answers
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Why do tracert latencies not add up to ping latency?

One might expect the sum of the tracert latencies to equal 267ms:
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2answers
3k 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!
4
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1answer
201 views

tcpdump on interface when pinging nonexistent hosts on local network

I've statically configured the IP address of an interface on a server: ip addr add 10.40.0.6/16 broadcast 10.40.255.255 dev eth1 If I try to ping a machine on the network (e.g., 10.40.0.1), it ...
4
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1answer
411 views

How can I use ping with a large packet size to troubleshoot network issues?

What types of network problems can be identified with ping of a large packet size?
4
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2answers
3k 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 ...
4
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3answers
6k 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 ...
4
votes
7answers
754 views

Scan for connected, powered on computers on a network?

I want to scan for powered on computers on my LAN and gather logs about that. I tried nmap but it didn't work very well (a lot of switched on computers are not getting detected). nmap -sP ...
4
votes
1answer
4k 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 ...
4
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2answers
3k 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 ...
4
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1answer
179 views

negative time for a ping echo reply

I was happily pinging in the net when suddenly: Pinging X with 32 bytes of data: Reply from .235: bytes=32 time=1444ms TTL=41 Reply from .235: bytes=32 time=1767ms TTL=41 Reply from .235: bytes=32 ...
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2answers
3k views

openvpn: connection established, can't ping server tun interface (debian server, windows & os x clients)

My goal: I want to set up openVPN on a vServer from the company netcup, running Debian squeeze. I only want a VPN connection from client to server; clients should not be able to see each other, also ...
3
votes
9answers
4k views

Why am I Unable to ping port 443 on Ubuntu?

I have opened port 443 through iptables: pkts bytes target prot opt in out source destination 45 2428 ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0 6 1009 ACCEPT tcp -- * * 0.0.0.0/0 ...
3
votes
2answers
860 views

How network devices affect TTL

When I do a ping, I can see the TTL value for each packet. For every router that I insert in between my computer and the router that connects to the internet, the TTL value goes down by one. However, ...
3
votes
3answers
313 views

Ping hostname returns another hostname in output : what does it mean?

When I ping the server sip3.voip-centrex.net, I get this output: PING sip3.voip-centrex.net (194.98.81.144) 56(84) bytes of data. 64 bytes from mpfrrelay.michaelpage.fr (194.98.81.144): icmp_req=1 ...