ARP issues with 3750X & 2960X Stack

[dean.anderson]

Unable to consistently ping a device from the 3750x that is connected to a vlan on the 2960x stack (po1 between 3750x and 2960x).  ARP statements appear normally in 3750x, where the interface vlan resides.  The device is pingable from through the 3750x, but not from the 3750x, even when specifying the Vlan Interface as the source.

Thanks for the help.

[Sarbjit-2014]

Hi Dean,

What if you dis-connect the device from 2960x stack and connect directly to the 3750x stack, in the same VLAN and try to ping.

What results do you get ?

Kind Regards...

[dean.anderson]

Connected device, then power cycled, then pinged:

lrs3750x-admin#ping 172.18.3.17             
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.18.3.17, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/7/34 ms
lrs3750x-admin#

Then, spiked the interface, because dot1x was lacking logs and not behaving properly:

lrs3750x-admin#      show arp | in 172.18.3.17          
Internet  172.18.3.17             0   Incomplete      ARPA

lrs3750x-admin#ping 172.18.3.17
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.18.3.17, timeout is 2 seconds:
.....

Clear arp no longer fixes the issue for the device.

Thanks!

[dean.anderson]

Update:

Added:

lrs3750x-admin(config)#Authentication mac-move permit

lrs3750x-admin(config)#aaa authentication enable default enable

Power cycled the device.  dot1x failed over to mab and successfully selected the correct vlan.

lrs3750x-admin#      show arp | in 172.18.3.17
Internet  172.18.3.17             0   0021.5a91.bd8a  ARPA   Vlan300

lrs3750x-admin#ping 172.18.3.17
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.18.3.17, timeout is 2 seconds:
!!!!!

15 minutes have past, still pingable.

We are going to look at the 2960x-Stack, next.

Thanks!

[dean.anderson]

Solution: We rebooted the 3750x and that cleared the problem.

Is this a documented bug?

Switch Ports Model                     SW Version            SW Image                
------ ----- -----                     ----------            ----------              
*    1 30    WS-C3750X-24S             15.2(2)E              C3750E-UNIVERSALK9-M    
 

Thanks!