Gratuitous ARP

We are running IOS 9.14(2.11) on a Dell S4048-ON. We have a network device that sends a Gratuitous ARP at power On. The following is what we see when plug the device directly into a server’s NIC:

ARP, Request who-has 192.168.1.88 tell 192.168.1.88, length 96

 

We do not see this ARP when patched into the Dell switch. I have a monitor setup to mirror that interface on the switch:

Sho monitor session 0

SessID  Source   Destination    Dir   Mode   Source IP   Dest IP DSCP TTL Drop Rate Gre-Protocol FCMonitor Status

0           Te1/2    Te 1/29            both  port     N/A            N/A      N/A   N/A No    N/A  N/A                 No             Enabled

 

 

When the network device is patched into a Dell Switch port the Gratuitous ARP is not seen by port monitor. The switch  is configured  with:

arp learn-enable

protocol spanning-tree 0

disabled

 

int ten 1/2

no ip address

mtu 9216

switchport

speed 1000

no negotiation auto

no shutdown

 

And  when SpanTree was enabled the interface also had:

spanning-tree rstp edge-port

 

When we use HP switches we see the ARP.  I have tried placing a dumb switch between the network device and the Dell switch, but still do not see the ARP reply. Again it is seen reliably when patched through the HP switch and directly to the server.

 

Thank you for any direction that you may be able to provide.