Here we go... simply replace the extension and you are good to go. 
http://asa.max1zzz.co.uk/English-North_American/Macintosh/System/CPU_Specific_Updates/Power_Mac_G3/G3_Ethernet_2.0.4.smi.bin
This is to my knowlege an issue and a fix specific to the beige G3 series... The pre-G3 Powermac's had an issue under certain circumstances where transferring large files across the inbuilt ethernet would hang the system, however this was covered by a seperate fix. This off memory affected the 75xx/85xx/95xx series and their related x6xx counterparts (also likely the 7300 and maybe WGS7350 as they use the same board architecture as the 7500 except with the AV subsystem componentry deleted.
http://asa.max1zzz.co.uk/English-North_American/Macintosh/System/CPU_Specific_Updates/Power_Mac_G3/G3_Ethernet_2.0.4.smi.bin
This is to my knowlege an issue and a fix specific to the beige G3 series... The pre-G3 Powermac's had an issue under certain circumstances where transferring large files across the inbuilt ethernet would hang the system, however this was covered by a seperate fix. This off memory affected the 75xx/85xx/95xx series and their related x6xx counterparts (also likely the 7300 and maybe WGS7350 as they use the same board architecture as the 7500 except with the AV subsystem componentry deleted.