From: https://www.mail-archive.com/compact.macs@mail.maclaunch.com/msg05659.html

the DaynaPORT 7.7.2 driver installs and seems to work on an SE/30 running OS7.5. Trying to update to version 7.5.5 of the OS crashed the mac.
Try this mirror of the mac driver museum: http://www.3rz.org/mirrors/macdrivermuseum/network.shtml

DaynaPORT7.7.2.sea - Drivers for all of Dayna's classic NIC cards. ( http://www.3rz.org/mirrors/macdrivermuseum/nic/DaynaPORT7.7.2.sea )