Linksys smart router slow download issue fix

If you experience slow download speed with Linksys smart router in Comcast network, you are encountering a bug in some Linksys smart routers. When it happen, ipv4 speed test will be slower than real speed. However, ipv6 is not throttled. Comcast speed test on ipv4 speed is always < 20m.

The cause is that IPv4 packets from the Comcast network are configured with DSCP 8, which Linksys smart routers will treat all package as low priority traffic and throttle their speed. ipv6 have correct DSCP so it is not affected.

If you are facing this issue and using stock firmware, you can use the small fix below:

1. reset Media Prioritization. In case you messed up any setting before.

2. enable Media Prioritization.

3. Add a New Application.


4. Add a name and input port range 1 to 65535.

Linksys Fix Ipv4

5. Drag the new added name to the High Priority box and save.

Linksys Fix Ipv4 Done

6. Test your speed again and you should see the speed back to normal.

One comment

  1. Thanks for posting this up, I had not realized that some of the slowdown may have been a result of ipv4 address space. I never really noticed it with my gaming, but my prior speed packages were only in the 40-60Mb range. Now that I've spiked up to 170+, I definitely want to make sure the LAN is being well fed from the outside.

Leave a Reply

Your email address will not be published. Required fields are marked *