Facing Layer 2 issue in MAC address not learning after certain time.

[D RAVI KUMAR]

 we installed new switch WS-C4500X-16 series switch with cat4500e-universalk9.SPA.03.09.00.E.152-5.E.bin as core switch and many work group switches is connected. received a complaint that user printer is not reachable in LAN. when we check for the printer MAC add in the core switch its shows incomplete. Either we do reboot the printer or when we ping the printer IP address from the core switch then the APR and mac add are learned and after that able to reach the printer IP address in LAN. 

can any one suggest on this issue.

[paul driver]

Hello
Default most switches have a cam timeout of 5 mins and arp is 4 hrs- Sounds like the printer goes to sleep.
Is this just occurring to this one printer?

res
Paul

[D RAVI KUMAR]

hi Paul,

Thanks for the reply.

But we are facing almost for all the printers in that location, when we ping the printer ip address from the core switch and soon after its start working. ( before doing that we are unable to ping the printer in LAN itself.)  

[Mark Malone]

set a static arp and static mac as there printers , if still an issue upgrade the ios versions theres a few buggy 4500x versions

if that doesn't work I would upgrade firmware , nics on printer side

[Paul Chapman]

Hi -

I would tend to agree with the IOS upgrade idea.  I've seen issues in some code versions where the switch will not flood unknown unicast from the CPU when the destination MAC is known via ARP cache but is no longer in the CAM.

The short term fix is to modify the arp timeout for the particular VLAN interface where you are having the issue.

interface vlan x
 arp timeout 240

PSC