Switch – Finding management IP on network

ipv4switch

I am trying to locate the IP address of a managed hirschmann switch in a small network set up in a spare room for the sake of learning about them as they are used at work. The switch in question [1of7] is acting like an unmanaged switch with no trace of any IP address – How do I find its IP address?

To eliminate the other switches that I have addresses into a new range of IPs, I linked the switch between a laptop and the gateway router, traffic passes through [I'm writing this question through the damm thing]
I ran tracert and only the gateway router comes up. It passes through traffic on all ports but no register of it on wireshark that I can see.
As well as wireshark, I tried angry IP, advanced IP, HIdiscovery, industrial HI Vision and found the addresses of 6 out of the 7 switches but can not get anything out of the 7th switch.

The switches were all Ebay purchases some new some 2nd hand unfortunately the seller didn't reset to factory settings with this one.

All the switches have a RJ11 v.24 serial port for management, I have spent the last few days making up serial cables trying different pin outs as the Hirschmann cable is 6 weeks away from Germany. I believe it is the same as the Schneider cable which has a description of pin out there website. I am also using a USB to serial converter which opens up com port 6. On one of the known switchs that I log in through webinterface it has all the telnet/ssh/bootP/v24 enabled but I can not open a telnet session with the switch. Mainly because I have little idea what I am doing, so if the answer to the question is use a serial cable, please be specific!

Best Answer

LLDP is the tool for discovering/visibility into switches on your LAN(s). BTW, if you don't have access to any of them via console, issue LLDP commands from your router, try and web into your default gateway, or load an LLDP client on your laptop. Something like https://www.hanewin.net/lldp-e.htm

Hirschmann Reference Manual

show lldp remote-data <{slot/port|all}> mgmt-addr Display the remote data's management address only.

4.8.13 lldp Enable/disable the LLDP/IEEE802.1AB functionality on this device. If disabled, the LLDP protocol will become inactive, but the LLDP MIBs can still be accessed. This command is a shorthand notation for lldp config chas sis admin-state {off|on} (see “lldp config chassis admin-state” on page 153). The default setting is on.

Related Solutions

Firewall – Finding IP Addresses for Social Network Sites

There are several ways to find the IP ranges of major organizations such as Facebook. The most basic of these, is to open up your terminal/command line of choice and issue the command: nslookup facebook.com.

This gives you the associated IP address to that DNS name; in this case, 173.252.110.27 was the answer from my DNS server.

Then run a "whois" lookup for that IP address (you can go to Whois.net if you don't have a whois tool in your command line): whois 173.252.110.27

The relevant output in this case is:

NetRange:       173.252.64.0 - 173.252.127.255
CIDR:           173.252.64.0/18
OriginAS:       AS32934
NetName:        FACEBOOK-INC

Facebook has been assigned the entire /18 block of 173.252.64.0/18, so simply use that range for your ACL.

Note: With all of that stated, blocking by IP can become cumbersome very quickly, and is highly ineffective in many cases. Organizations the size of Facebook will constantly be adding new IP space, which will be outside of your filtered range.

Some sites might change to using a new CDN, which of course will use a different IP space as well.

If you're having specific issues with your HTTPS and URL blocking, depending on the equipment, you could ask in another question for assistance on those specific problems. The answers might better aid you in blocking access to these sites.

Finding the network and host address, and maximum number of host addresses

A subnet of an IP network has a range of IP host address from 172.19.40.1 to 172.19.47.254.

What is the maximum number of host addresses that can exist on this subnetwork? I'm googling but not found a clear answer. how should we compute maximum number of host addresses?

Method 1

Let's use a simple method to find this...

IP addresses contain four 8-bit integers; 8-bit integers have a maximum value of 255. Think of it like this... if we merely build a sequence of third-octets from 40 to 47 and account for the hosts, we'll find the answer with minimal math...

172.19.40.1 through 172.19.40.255 = 255 hosts
172.19.41.0 through 172.19.41.255 = 256 hosts
172.19.42.0 through 172.19.42.255 = 256 hosts
172.19.43.0 through 172.19.43.255 = 256 hosts
172.19.44.0 through 172.19.44.255 = 256 hosts
172.19.45.0 through 172.19.45.255 = 256 hosts
172.19.46.0 through 172.19.46.255 = 256 hosts
172.19.47.0 through 172.19.47.254 = 255 hosts

Number of hosts = 2*255 + 6*256 = 2046 hosts

Method 2

Use this method to find the number of hosts between two arbitrary IP addresses... convert the two 32-bit IP addresses to integers and subtract...

172.19.40.1 => 2886936577
172.19.47.254 => 2886938622

2886938622 - 2886936577 + 1 = 2046 hosts

Note that I added an extra host in the subtraction, since you're including the first host in the list of available hosts.

As someone mentioned below you can also use the host bits of the netmask, if you're merely calculating the number of hosts in an IP CIDR block.

How to convert an IPv4 addess to decimal:

172*256**3 + 19*256**2 + 40*256**1 + 1*256**0 = 2886936577