Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

These are not Cisco switches or switches with serial cables. They are also on a live 24/7 business network. I was tasked with doing some network work but I don't know the switches IP address and neither do they.

Doing a tracert does not show the switches since they sit in the same subnet IP space. Doing a tracert is just jumps to the gateway's IP.

How do I find the IP of the switches on the same subnet?

share|improve this question
1  
These are managed switches correct? –  phoebus Nov 16 '13 at 18:59
1  
The reason I ask is that if these are unmanaged switches they won't have an IP address. On managed, non-multilayer switches, IP addresses exist solely for management purposes. They will never appear in your tracert output, whether or not they are on the same subnet as your host, because the switches do not operate on your traffic at layer three. I just want to make sure we're on the same page as your tracert comment indicates you may be misunderstanding the nature of host-to-host communication. –  phoebus Nov 16 '13 at 19:54
    
Not sure why kind of switches they are atm. So I take it unmanaged means plug-n-go, right? Thus no IP and no configuring. –  Frank Thornton Nov 16 '13 at 20:12
    
Yup, unmanaged means no management interface, just a flat layer 2 domain. –  phoebus Nov 16 '13 at 20:15
1  
A switch will only show up in tracert if it's a Layer 3 switch and it's actually routing, regardless of what "subnet space" it's in. –  joeqwerty Nov 16 '13 at 21:59
add comment

1 Answer 1

up vote 2 down vote accepted

Scan the whole subnet and look for the MAC address of the switch. (If this is a 24/7 network, I assume you know the MAC addresses...)

share|improve this answer
    
Like use nmap to scan the entire subnet? –  Frank Thornton Nov 16 '13 at 18:40
    
Nmap or some network discovery tool. –  Ward Nov 16 '13 at 18:46
    
E.g. ManageEngine is one I haven't heard of before: manageengine.com/products/oputils/free-network-tools.html –  Ward Nov 16 '13 at 18:53
    
Any MAC address scanner should do. If you know what vendor these switches are from they should be readily identifiable from the OUI. A MAC address scanner works by ARP'ing for every ip address in the subnet and recording the responses. It should then list every device that responded to the ARP request with the MAC address, ip address, vendor and host name. Here's one I use quite often - colasoft.com/mac_scanner –  joeqwerty Nov 16 '13 at 21:49
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.