Show IP address of specific port

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I had a switch "dissapear" from our network but it is still plugged in to the appropriate port. In short, the switch on that port has an IP, internet connectivity and packets can move between our vlans but I cannot ping the switch or the devices it's connected to. If I know the port and MAC, how do I look up it's IP from inside the extreme switch?
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Ben Kessell

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Posted 3 years ago

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Colatuno, Joe, Escalation Support Engineer

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Hey Ben,

You would want to run "show fdb <mac address>"  or "show fdb <port #>.

If this is an extreme switch on the other side, you can run "show edp"
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Ben Kessell

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"show fdb <port #>" gives me the mac addresses on that port but no IPs. "show fdb <MAC>" also only returns the mac address as well as "show fdb <vlan name>".

Is there another way?
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Colatuno, Joe, Escalation Support Engineer

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try "show iparp <mac address>"  if there is an IP address on the vlan
(Edited)
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EtherMan

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If the other switch is an Extreme and they have common layer 3  management vlan between them then a show edp port (connecting port ) detail will show you the ip address of connected Extreme switch.  If you know the mac address of that switch then you can also go to another switch/router and use that mac to find the arp entry.  

One thing we have seen happen on some of the older XOS switches is they will loose their management and stop replying to polls but continue to pass traffic... This usually is the beginning of the end... If that is the case a reboot may bring it back but you need to look at code rev and upgrade if it is out of date... good luck ! 
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Ben Kessell

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The other switch is an Enterasys 800 series so they do not share L3 management so show edp port returns nothing.

When you say "go to another switch and check the arp table" what do you mean? The main switch is a stack and this is an independent switch at a testing station. I've tried arp -a on the machine it's on and I only get the gateway address of the entire vlan and not the switch it's on.
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EtherMan

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Sorry for all that then... I have 18 years being a purple user but zero on the E-800 series... If the switch that is not responding has to share a common subnet with something you can get to to see if there is an arp entry in the table for that mac address.  If not it sounds like serial cable and console session time 
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Brian Anderson

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Might try 'show neighbors' or 'show arp'
Also if you have console running you can search in compass on that switch on and perhaps pick out the ip address there. 
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Roberto F.

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You can try to enable cdp (on enterasys i think is enabled by deafult) and lldp and if it is enabled on the remote device you can see some information about it.
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Alice Grandi

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I have a little experience with 800-Series, I can confirm that you won't be able to see their ip address from the other switches on the same network unless you enable LLDP on the 800-Series. You can do it through webview, under "L2 Features" you should find "LLDP Global Settings" or something similar, then set LLDP state to "enabled" and Apply. This applies to 08H20G4 but I think it's similar on all 800-Series switches.