Showing results for 
Search instead for 
Did you mean: 

MAC string updated Error on 12406 IOS.


I'm observing following error message on 12k router.

%TFIB-7-SCANSABORTED: TFIB scan not completing.  MAC string updated.

i've confirmed that there is no arp changes occurs but cef events trigger frequenty due to high number of BGP peers ( IX /  200+)

only think i could notice is arp age time on most of the arp entries is 0 ( suspect gratious arp )

Please advice me on following cef events because "show ip cef events within 1 " shows mostly ADJ update .

does it mean some arp changes occurs ?

+00:00:00.220:           *.*.*.230/32     ADJ (Gi2/0/0) update   [OK]

Anyone encountered following error.

This is the explation from cisco but couldn't find any interface adjacency  change , in the current enviroment.

If the TFIB scanner did not complete the first scan and the CEF scanner receives more than 60 requests to update TFIB0, then the %TFIB-7- SCANSABORTED: TFIB scan not completing messages are displayed. If the message ends with MAC string updated, such as %TFIB-7-SCANSABORTED: TFIB scan not completing. MAC string updated, then the message means that the adjacency string for an interface keeps changing. This is mostly due to a wrong setup or configuration

1 Reply 1


what I've found is when the MAC age time reset to 0 cef event trigger update ADJ.  But if anyone doing proxy arp / routing to interface we could see broadcast arp request which will update the MAC timer to 0 . is it a desired behavior ?

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: