We still use NetDB as a troubleshooting tool. It can quickly identify what switch and vlan a MAC address is on. I also heavily use it for checking the last time a MAC address was seen on the network and for cleaning up old DNS entries.

Anyway, I recently migrated NetDB to RHEL8 and discovered a new error while testing.

Database Transaction Error (MAC): Update Failure in mac for d49e.3bxx.xxxx: Data too long for column 'vendor' at row 1

NetDB has a cronjob setup that downloads an updated MAC Vendor Database every month. You can grep that file for failing MAC address.

$ cat /opt/netdb/data/oui.txt | grep D4-9E-3B
D4-9E-3B   (hex)   Guangzhou Shiyuan Electronic Technology Company Limited

NetDB could update that table to support more characters. However, the program is not really supported anymore and has not seen updates in a long time. A simple work around for this error is to just shorten this company name when the file is downloaded.

This is my new cronjob that does just that. I think this is a pretty basic, but cool example of what sed can do.

0 5 15 * * wget -q -O - http://standards-oui.ieee.org/oui.txt | sed 's/Guangzhou Shiyuan Electronic Technology Company Limited/Guangzhou Shiyuan Electronic Technology/' > /opt/netdb/data/oui.txt

Now when the new oui.txt is downloaded the MAC address vendor can be properly added to the table.

$ cat /opt/netdb/data/oui.txt | grep D4-9E-3B
D4-9E-3B   (hex)   Guangzhou Shiyuan Electronic Technology

It is not perfect and can break again if we run into another long vendor name.

I am happy with it for now.