Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Ping gets 2 addresses

Posted on 2014-02-14
40
Medium Priority
?
350 Views
Last Modified: 2014-02-17
When  I ping an address in my local network, I get responses from 2 different IP addresses. What would cause this?
0
Comment
Question by:tenchulyo
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 16
  • 15
  • 7
  • +2
40 Comments
 
LVL 14

Expert Comment

by:Justin Yeung
ID: 39859538
do you have multiple names under your DNS on the same ip address?

or it is a domain root?
0
 

Author Comment

by:tenchulyo
ID: 39859578
Sorry, I'm just a dumb programmer...LOL...can you elaborate on that...Thanks Again!
0
 
LVL 26

Expert Comment

by:Fred Marshall
ID: 39859579
Is it possible that one device has two IP addresses assigned to the same NIC?
I've not tried pinging one set up that way it but it seems possible for this to happen if you did.
0
Turn your laptop into a mobile console!

The CV211 Laptop USB Console Adapter provides a direct Laptop-to-Computer connection for fast and easy remote desktop access with no software to install.

 

Author Comment

by:tenchulyo
ID: 39859589
So you're saying it is possible to add multiple IP's to a MAC on a DHCP, wouldn't that cause IP conflict?
0
 
LVL 14

Expert Comment

by:Justin Yeung
ID: 39859601
as you said "ping an address", are you ping IP or Name?
0
 

Author Comment

by:tenchulyo
ID: 39859605
an address 192.168.4.113
0
 
LVL 26

Expert Comment

by:Fred Marshall
ID: 39859619
No it doesn't cause a conflict.
Level 2 switches will indeed work using MAC addresses but the MAC addresses have to be translated from the IP addresses.
So, the ARP table should show two IP addresses, each with the same MAC address.
Either IP address will work that way.

Conflicts arise when the same address belongs to two separate devices because then there's an issue of "where to go?"
There's no conflict when the same device has two addresses because there is no question of "where to go?"
0
 
LVL 14

Expert Comment

by:Justin Yeung
ID: 39859628
you can have multiple IP address on a single network adapter without problem.

you can add an alternate ip address on a windows box.
0
 

Author Comment

by:tenchulyo
ID: 39859633
Well, not sure if this helps but when I do a arp -a it says "no ARP entries found"
0
 
LVL 14

Expert Comment

by:Justin Yeung
ID: 39859647
do you have a management layer 2 switch that connected the device?
0
 
LVL 26

Expert Comment

by:Fred Marshall
ID: 39859663
Sometimes one needs to ping in order to refresh the arp cache.
I would ping both addresses and then follow shortly with arp -a
0
 

Author Comment

by:tenchulyo
ID: 39859680
The switch it is connected to directly is Unmanaged (Netgear Prosafe), I can go check the trail to see all switches that are involved in the connection...the PC I'm pinging from is in another site.
0
 
LVL 14

Expert Comment

by:Justin Yeung
ID: 39859694
fmarshall,

you might not able to see that in a windows machine, and he doesn't have a managed switch to troubleshoot.

tenchulyo,

is the target machine a windows box?

if it is, check if you have 2 IP assigned on the machine.
0
 
LVL 6

Expert Comment

by:Sasha Kranjac
ID: 39859717
A high level overview:

A name, for example www on microsoft.com, or www on google.com domains can have multiple entries in DNS. Pinging either www.microsoft.com or www.google.com would return different IP addresses.
Try to run nslookup.exe at a command prompt and type either www.microsoft.com or www.google.com. As the result you will get multiple IP addresses.

It is also possible to set up a single network card in Windows (Server or Client) with multiple IP adresses, even from different subnets. That way you can access computers from different subnets.
0
 
LVL 26

Expert Comment

by:Fred Marshall
ID: 39859721
fmarshall,

you might not able to see that in a windows machine

I'm not sure what was meant by "see" or "that"....???

In Windows XP:
Network Connections
Local Area Connection ... (or?)
Internet Protocol (TCP/IP) Properties
Advanced TCP/IP Settings
IP Address <<< window will show all the IP addresses assigned.

Windows 7 is the same....

So, in this context, one is able to see that in a Windows machine.
0
 
LVL 14

Expert Comment

by:Justin Yeung
ID: 39859724
sorry I meant the arp info even after you ping the ip
0
 
LVL 14

Expert Comment

by:Justin Yeung
ID: 39859730
or there are 2 adapters "wired and wireless", so then you got 2 ip from the dhcp server on the same dns name
0
 

Author Comment

by:tenchulyo
ID: 39859738
fmarshall,

I went into the machine and everything says obtain automatic (IP & DNS)
0
 

Author Comment

by:tenchulyo
ID: 39859743
Also, this machine has no wireless only 1 NIC
0
 
LVL 26

Expert Comment

by:Fred Marshall
ID: 39859823
Well, maybe you could use Wireshark on the pinging computer to see what MAC addresses come back with the pings..... something like that.
0
 
LVL 14

Expert Comment

by:Justin Yeung
ID: 39859881
can you put the ping result on here?
0
 

Author Comment

by:tenchulyo
ID: 39859912
Ping
Sure...Here it is.
0
 
LVL 14

Expert Comment

by:Justin Yeung
ID: 39859922
are you pinging from the machine that has 192.168.4.113?
0
 

Author Comment

by:tenchulyo
ID: 39859927
where should I ping to from 192.168.4.113
0
 
LVL 26

Expert Comment

by:Fred Marshall
ID: 39859931
now, after the ping, will arp -a show the MAC address?
0
 
LVL 14

Expert Comment

by:Justin Yeung
ID: 39859933
it should if you have a management switch..........not sure it will show up on a windows machine.
0
 

Author Comment

by:tenchulyo
ID: 39859938
192.168.0.242 is the machine I'm on locally

192.168.0.126 is the mystery machine
0
 
LVL 14

Expert Comment

by:Justin Yeung
ID: 39859946
if you ping 192.168.0.126 since it is on the same subnet......

then do a arp -a on the machine of 192.168.0.242

if you can see the mac address of the mystery
0
 

Author Comment

by:tenchulyo
ID: 39859977
ARP -a

Here are the ARP results For the sake of security I blacked out the last 2 sections
0
 
LVL 14

Expert Comment

by:Justin Yeung
ID: 39860013
what is your dhcp server? hardware or software?
0
 
LVL 44

Expert Comment

by:Darr247
ID: 39860036
I suspect there's a VPN present that we haven't been told about, and proxy-ARP is making the connection[s] happen for the pings.
0
 

Author Comment

by:tenchulyo
ID: 39860048
Well, it's windows driven, if that is what you are asking...not using the router's software.
0
 
LVL 14

Expert Comment

by:Justin Yeung
ID: 39860058
you have a unmanaged switch. so I believe you only have one subnet on your local network.

the .4.x address is not on the same network. it could be a VPN connection as mentioned by Darr247
0
 

Author Comment

by:tenchulyo
ID: 39860085
Well I do believe there are more than 2 sub nets. .14.x and .9.x also exist. The VPN I know exists is to a vendor we contract, but their IP's begin with 10.1.100.X they host a huge application. Does this clarify things more... We use sonicwalls to connect the sites. Sorry, I'm trying to be as detailed as possible.
0
 
LVL 14

Expert Comment

by:Justin Yeung
ID: 39860111
you have a unmanaged switch but using 2 subnets? how does it route your traffic?

would you please provide more detail on your network diagram.
0
 

Author Comment

by:tenchulyo
ID: 39860115
Like I said, I'm the programmer...the reason I'm here is to try and be proactive because the IT dept can't figure out the problem and it is making my application respond incorrectly. I know the app works perfectly, I've tried it in virtual networks and other sites without any issues.
0
 
LVL 14

Accepted Solution

by:
Justin Yeung earned 1500 total points
ID: 39860117
this is probably your problem, you have a unmanaged switch with multiple network on it....

http://answers.yahoo.com/question/index?qid=20070828235104AA8NYiT
0
 
LVL 26

Expert Comment

by:Fred Marshall
ID: 39860305
what do you get if you do this command:

tracert 192.168.4.113

?
0
 

Author Comment

by:tenchulyo
ID: 39860542
YES Justinyeung!!!

You got it! Now, It says I can setup a vlan to correct the issue. The switch does support vlan,
however, i am not familiar with this technology... how do I set this up on a netgear plus prosafe (GS105E). Any ideas?
0
 

Author Comment

by:tenchulyo
ID: 39865107
Nevermind...just taught myself everything over the weekend and fixed my issue...thanks to all!
0

Featured Post

Put Machine Learning to Work--Protect Your Clients

Machine learning means Smarter Cybersecurity™ Solutions.
As technology continues to advance, managing and analyzing massive data sets just can’t be accomplished by humans alone. It requires huge amounts of memory and storage, as well as high-speed processing of the cloud.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Transparency shows that a company is the kind of business that it wants people to think it is.
Join Greg Farro and Ethan Banks from Packet Pushers (http://packetpushers.net/podcast/podcasts/pq-show-93-smart-network-monitoring-paessler-sponsored/) and Greg Ross from Paessler (https://www.paessler.com/prtg) for a discussion about smart network …
In this video we outline the Physical Segments view of NetCrunch network monitor. By following this brief how-to video, you will be able to learn how NetCrunch visualizes your network, how granular is the information collected, as well as where to f…
Michael from AdRem Software explains how to view the most utilized and worst performing nodes in your network, by accessing the Top Charts view in NetCrunch network monitor (https://www.adremsoft.com/). Top Charts is a view in which you can set seve…

670 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question