I agree with arthurwinslo
Which version of the cisco Linksys e4200 router do you own?
if its version 1 then its got the Broadcom chipset and is from my experience the better performer.
if its version 2 then its got the Marvel chipset and its performance is erratic.
The CISCO DPC3825 in bridge mode is the preferred configuration IMO.
When doing tests with the DPC3825 and the E4200 v1 always start from a power down point for both devices;
This means  power down the DPC3825 and wait 2 minutes then power up the DPC3825
This means  power down the E4200 and after the 2 minute wait from step  power up the E4200 ONLY after you see the DPC3825 have 4 solid green LED's
When doing tests with the DPC3825 and the E4200 v2 always start from a power down point for both devices as described above but your results will probably be very mixed.
Regardless of which version make sure that your E4200 has the most updated firmware.
If your E4200 is version 1 and you are still getting mixed results after running your tests then I would suspect the DPC3825 is having issues on the Internet port.--
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