Humminbird Interlink Caution
I have had a 997C for a while now and put it on my new boat last fall. Just added an 858C to the bow and Interlinked the two. 997 has firmware version 4.95 and 858 had version 4.88 out of the box. Everything worked.
I went to update the 858 to version 4.97 only to find only version 5.21 available for download. After loading 5.21 to the 858, the two units will no longer communicate. The new firmware does appear to activate the ethernet port.
Be careful with your firmware versions to keep all of the equipment happy especially if you have new and older units. I guess I'll be contacting Humminbird to see if I can get either updated firmware for the 997 or more likely revert to a previous version for the 858 to get the Interlink working again.