Second IP address on single NIC will not work.

Posted on 2008-01-31
Medium Priority
Last Modified: 2013-12-23
I'm trying to make some second IP address work on a network. I've added the IP addresses of and on a couple of machines by using the advanced tab on the TCP/IP properties of the network connection in windows. However when I try to ping from one to the other it doesn't work. I've included the "ipconfig /all" and "ping" results from one of the machines. The wierd thing is that when I try to ping one of these new addresses, I get a reply on the first try followed by three "Request timed out." (please see attached code snippet).
Subsequent ping attempts will result in 100% loss, but if I try again after awhile or after a restart, then I get the 75% loss all over again followed by 100% loss on subsequent tries.
Any help would be appreciated.
Ethernet adapter Local Area Connection:
        Connection-specific DNS Suffix  . :
        Description . . . . . . . . . . . : Broadcom NetXtreme 57xx Gigabit Controller
        Physical Address. . . . . . . . . : 00-1D-09-13-58-B9
        Dhcp Enabled. . . . . . . . . . . : No
        IP Address. . . . . . . . . . . . :
        Subnet Mask . . . . . . . . . . . :
        IP Address. . . . . . . . . . . . :
        Subnet Mask . . . . . . . . . . . :
        Default Gateway . . . . . . . . . :
        DNS Servers . . . . . . . . . . . :
C:\Documents and Settings\cad>ping
Pinging with 32 bytes of data:
Reply from bytes=32 time<1ms TTL=128
Request timed out.
Request timed out.
Request timed out.
Ping statistics for
    Packets: Sent = 4, Received = 1, Lost = 3 (75% loss),
Approximate round trip times in milli-seconds:
    Minimum = 0ms, Maximum = 0ms, Average = 0ms

Open in new window

Question by:Spelurker
LVL 21

Expert Comment

ID: 20792238
I am not quite clear on your first statement if you are assigning the same IP address to two different computers you will have an IP address conflict. Even if it is the alternate configuration I would not recommend this.

The alternate configuration only works if DHCP is not available it is a fallback configuration
LVL 12

Expert Comment

ID: 20792259
Why are you having 2 gateways?

Assisted Solution

steezy earned 2000 total points
ID: 20792266
I think you should decide on what you are trying to accomplish and ask that question instead.
Will You Be GDPR Compliant by 5/28/2018?

GDPR? That's a regulation for the European Union. But, if you collect data from customers or employees within the EU, then you need to know about GDPR and make sure your organization is compliant by May 2018. Check out our preparation checklist to make sure you're on track today!


Author Comment

ID: 20792370
-They are all static IP's. I'm assigning second IP's to individual machines, not the same IP addresses. (example and
-I threw the second gateway in there just to see if that would resolve the problem; it didn't. is the original working gateway. I'll remove that.
-What I'm trying to accomplish is this: We have to add a network device (It will act somewhat like a specialized gateway that attaches to a PES/satellite) that is in the 10.42.x.x range and the other machines need to be able communicate with it. All of the machines are in the same subnet (10.4.3.x). I was told by the vendor that all I would need to do is add a second IP address to the individual machines in the range of 10.42.x.x.

Accepted Solution

steezy earned 2000 total points
ID: 20792449
well if you are using the network with a subnet mask of, the IP's those computers already had are in the same subnet as the addresses. In this configuration, anything starting with "10." would be in the same network.

Author Comment

ID: 20854809
Fixed it. The problem was that the VLAN on the Cisco switch needed to have a secondary network added to it (10.42.x.x). Still doesn't explain why the first ping went through, but not any of the subsequent ones; but, alls well that ends well.

Expert Comment

ID: 21460166
We hate to see questions like this left opened. In network engineering the alls well that ends well scenario doesn't really work. Everything happens for a reason, usually user error. In your scenario theres too many variables that you provided no information on.  A prime example is the VLANS, which you failed to mention up front. How those VLANS are configured is anyones guess, so why your ping went through is likewise anyones guess, but its most likely related to a cross connection somewhere on your VLANs. What you want to do in the future is approach these sorts of errors from a pragmatic approach. That means first and foremost, utilizing a "Sniffer" whenever possible. A network engineer is blind without a protocol analyzer, and given that they are free, see "WireShark" (formerly Ethereal) theres no excuse for troubleshooting a network issue without one, particularly if you have a cisco switch capable of Port Spanning, which yours most likely is given it is VLAN capable.  Simply span the associated ports and examine the packet captures. The answers always there.

Also you might try examining the ARP cache next time. This is a simple process of simply typing "arp -a" from a DOS command prompt on the involved system. This will show you whether or not the computers are communicating at Layer 2 (where VLANS operate) which in turn will show you where the problem likely lies. In your case, the two systems being on seperate VLANS means that your ARP cache would have been empty, at least on one machine. This would have alerted you to Layer 2 blocking, hence VLANS.  

Also, one final note, you mentioned you once tried setting the gateway. Obviously you learned that didn't work. Just FYI, you're fine with the secondary addressing for certain applications like NAT applications but you can only have one gateway. If you're troubleshooting this stuff in the future do your IPCONFIG, and then do an arp -a. Lots of answers lie in the arp cache.


Featured Post

[Webinar] Improve your customer journey

A positive customer journey is important in attracting and retaining business. To improve this experience, you can use Google Maps APIs to increase checkout conversions, boost user engagement, and optimize order fulfillment. Learn how in this webinar presented by Dito.

Question has a verified solution.

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

This article offers some helpful and general tips for safe browsing and online shopping. It offers simple and manageable procedures that help to ensure the safety of one's personal information and the security of any devices.
Resolve DNS query failed errors for Exchange
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…
This video tutorial shows you the steps to go through to set up what I believe to be the best email app on the android platform to read Exchange mail.  Get the app on your phone: The first step is to make sure you have the Samsung Email app on your …
Suggested Courses

588 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