topic Getting IP address of connected devices on 4800/4900 ERS switches in ExtremeSwitching (VSP/Fabric Engine)

Getting IP address of connected devices on 4800/4900 ERS switches

Roc156 — Thu, 10 Sep 2020 19:01:16 GMT

I have a few 4800 and 4900 switches. Is it possible to get the IP address of connected devices? The only way I can get any IP address of a device is for Avaya VoIP phones using the command show lldp neighbor med inventory.

Re: Getting IP address of connected devices on 4800/4900 ERS switches

Dilraj_Singh_Kh — Thu, 10 Sep 2020 19:12:45 GMT

Try "show autotopology nmm-table"

Re: Getting IP address of connected devices on 4800/4900 ERS switches

Roc156 — Thu, 10 Sep 2020 19:19:45 GMT

It only shows IPs of connected switches not PCs.

Re: Getting IP address of connected devices on 4800/4900 ERS switches

Dilraj_Singh_Kh — Thu, 10 Sep 2020 21:14:24 GMT

To check the IPs for the end device, i guess "show lldp neighbors" would be the only way to check. You might can check the IPs using ARP table as well if that can help.

Re: Getting IP address of connected devices on 4800/4900 ERS switches

Roc156 — Thu, 10 Sep 2020 22:08:26 GMT

show lldp neighbors and sh mac-address-table only shows me MAC addresses.

sh arp shows me the IP and MAC addresses of our cores which are ERS8810

Re: Getting IP address of connected devices on 4800/4900 ERS switches

Martin_Sebek — Fri, 11 Sep 2020 00:57:10 GMT

It depends on the switch configuration. For example if you are using feature called dhcp-snooping you can get the binding table.

show ip dhcp-snooping binding

But of course only for clients who are using dynamic addresses.

Re: Getting IP address of connected devices on 4800/4900 ERS switches

Roc156 — Fri, 11 Sep 2020 02:48:17 GMT

We normally set the dhc-snooping trusted on the trunk ports and to the PC VLAN.

ip dhcp-snooping vlan 100

interface ethernet 49-50
ip dhcp-snooping trusted

How would it affect if it is set to binding?

Re: Getting IP address of connected devices on 4800/4900 ERS switches

Roc156 — Fri, 25 Sep 2020 22:23:19 GMT

I noticed that in COM 3.0 I can see and search for IP devices under Routing Manager and selecting any one of our Layer 3 core switches.

Routing Manager / IPv4 Networks / IP Routing / ARP

I notice it shows the Interface as a number in the VLAN name. Example 4321 in PC

How can I cross reference that Interface to the switch that is connected to?

Re: Getting IP address of connected devices on 4800/4900 ERS switches

Miguel-Angel_RO — Fri, 25 Sep 2020 22:33:53 GMT

Roc156,

On your core do a “show ip arp”, you’ll get all the known IP’s with the corresponding port (switch connected)

/if they are configured with SPBM, you can run “show vlan remote-mac-table vlanid” but I’m not sur if /the ERS8810 support it.

if you do a “show mac-address-table” on the ERS you’ll get the MAC and the port.

MS Excel will do the rest 😉

Mig

Re: Getting IP address of connected devices on 4800/4900 ERS switches

Roc156 — Fri, 25 Sep 2020 23:31:16 GMT

SPBM is not enabled.

So I will need to do “sh ip arp” on the core and I’ll get the IP and MAC address, along with which switch it is connected to. Then I connect to the switch and run the “show mac-address-table” and search for the MAC address and I’ll be able to see the port to which it is connected.

Is that bout right?

Re: Getting IP address of connected devices on 4800/4900 ERS switches

Miguel-Angel_RO — Sat, 26 Sep 2020 15:56:31 GMT

Almost,

you can also do “show lldp neig” and “show autotop nm” do get additional info on the switches connected to the core.

Mig