I don't know how much data you have, but your data structure is horrible and should be re-done. You never hardcode data elements (such as manufacturer) as columns in a table. What if they change - you may have to find and retype many, many references to those columns. And what if you want a report of manufacturers? Can't do that easily since they're column names, and not data.
A well-designed database is granular (e.g., many separate tables) and flexible enough to accommodate more data and additional requirements. You NEVER want a narrowly focused database, because requirements may expand down the road, and an overhaul is difficult. If you're dealing only with routers now, great. But that may change.
You may not appreciate this answer, but this is how your database should be constructed, and how your form should work.
Create a table called Hardware Types. Like the above, HWTypeID is the auto-number primary key, and HardwareType is, for example, "Router".
Create a table called Manufacturers, with two columns: MfrID is an auto-number, primary key. Mfr is the manufacturer name.
Create a table called Models, with three columns: ModelID is an auto-number, primary key. Model is the model name/number. MfrID is a lookup field to the Manufacturers table, and includes both the primary key and the manufacturer name.
Finally, create a table called Hardware. HWID primary key. HWTypeID, MfrID and ModelID are lookups to the tables created above.
Populate all tables, except Hardware, with data. Do this in the order they were created because, for example, you can't complete a model record until you can link to a manufacturer record.
Create a form called Hardware, based on the Hardware table. From the Field List (under View on the menu), drag and drop all fields on the form. I usually hide the key column - the user has no need to see that.
All that's left is to synchornize the Mfr and Model drop-downs on the Hardware form. Open the Properties window for MfrID. On the Events tab, select [Event Procedure] for the After Update property. Next click the ellipsis button to the right. This will bring up the event procedure code to be run after the manufacturer is updated. The procedure is currently empty. You'll be adding just one line of code: Me!ModelID.Requery.
Next, look at the Properties window for ModelID. Click the ellipsis to the right of the Row Source property. This will bring up the query used to populate the model drop-down. You'll likely see only two fields (ModelID and Model). Drag down MfrID into the third query column. In the Criteria row under MfrID, type [Forms]![Hardware]![MfrID], and then close the query window and form, saving all the way.
What the two paragraphs above do is make the model drop-down dependent on (synchronized with) the manufacturer drop-down, and force a requery of the model drop-down every time the manufacturer is changed.
That's it. Using the hardware form, you'll populate the Hardware table with all of your routers.
Of course, you can more fields to the Hardware table and form based on whatever your needs are.