cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
208
Views
0
Helpful
1
Replies

LAN - ARP Table

peterledwidge
Level 1
Level 1

Hello,

I'm not sure if someone has come across this before. But they might enlighten me.

Under what circumstances would you see ARP enteries on a switch for subnets out side of the local subnet?

Example 2 switches back to back everything in default vlan 1. These uplink to a pair of routers running HSRP.

I would expect to see x.x.x.200 /24

arp enteries for devices on the switches

but not addresses outside of this range.

Any input appreciated.

Thank you.

1 Reply 1

lgijssel
Level 9
Level 9

Suppose you are talking layer2 switches like the 2950 series?

First of all, this has nothing to do with the switching process on the access ports. The arp table on a switch is only used for the IP management interface. ARP entries will appear for anything that you contact from the console.

Typically anything beyond your local subnet is covered by a default gateway but when the switch is using proxy-arp for address resolution you can see anything on your network.

Regards,

Leo

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Innovations in Cisco Full Stack Observability - A new webinar from Cisco