We are no longer in the days of just WRT54Gv1. We have moved on to several revisions and several models. This quick guide will help you find out which one you have. This is important for several reasons. With the expanding versions, some firmware versions only support certain hardware versions.

First, find the Linksys sticker on the bottom of your router. Find the serial number and most importantly the first 4 letters of it.

Secondly, look below to find your hardware version.

CDF0 = WRT54G v1.0
CDF1 = WRT54G v1.0
CDF2 = WRT54G v1.1
CDF3 = WRT54G v1.1
CDF5 = WRT54G v2.0
CDF7 = WRT54G v2.2
CDF8 = WRT54G v3.0
CDF9 = WRT54G v3.1
CDFA = WRT54G v4.0
CDFB = WRT54G v5.0
CDFC = WRT54G v5.1
CDFD = WRT54G v6.0

CL7A = WRT54GL v1.0
CL7B = WRT54GL v1.1

CGN0 = WRT54GS v1.0
CGN1 = WRT54GS v1.0
CGN2 = WRT54GS v1.1
CGN3 = WRT54GS v2.0
CGN4 = WRT54GS v2.1
CGN5 = WRT54GS v3.0
CGN6 = WRT54GS v4.0
CGN7 = WRT54GS v5.0
CGN8 = WRT54GS v5.1

CJK0 = WRTSL54GS v1.0

SJH0 = WTR54GS v1.0