SBG8300 - Firewall attempts and 1% packet loss

  • 24 November 2023
  • 1 reply


I noticed that in my firewall logs there are a lot of attempts.  Not sure if this is normal or not but I have also been having issues with upload packet loss where I usually have 1% or less than 1% upload packet loss.  Sometimes it can be worse, however I thought maybe if there is a lot of resources used on the firewall, then some packets may be getting dropped.  Been having this issue for a while now.  I use ethernet and also got a new line going to my house.  I saw online that the SBG8300 has a puma 7 chipset which is defective, however I’m not sure if this is linked to my 1% packet loss at all.  


Here is an example of my firewall log: (this is just from a few hours after i hard reset the modem from the button on the back)

FW.IPv6 INPUT drop 522 attempts 11/24/2023 05:11:23 Firewall Blocked
FW.IPv6 FORWARD drop 273 attempts 11/24/2023 05:05:47 Firewall Blocked
FW.IPv6 INPUT drop 9 attempts 11/24/2023 04:58:01 Firewall Blocked


My upstream power levels are around 40 which I saw some stuff about arris saying it should be 45-51 so not sure if that is a potential issue as well or not 

Upstream QAM

Index Frequency (Hz) Power Level (dBmV) Channel Type Symbol Rate (KSym/sec) Modulation Lock Status
7 16400000 40.770599 US_TYPE_STDMA 5120 KSym/sec 64QAM ACTIVE
12 40400000 41.260300 US_TYPE_STDMA 2560 KSym/sec 64QAM ACTIVE
10 35600000 41.520599 US_TYPE_STDMA 5120 KSym/sec 64QAM ACTIVE
9 29200000 41.270599 US_TYPE_STDMA 5120 KSym/sec 64QAM ACTIVE
8 22800000 41.020599 US_TYPE_STDMA 5120 KSym/sec 64QAM ACTIVE
6 10400000 40.260300 US_TYPE_STDMA 2560 KSym/sec 16QAM ACTIVE



Under CM Error Codewords I also notice there are a lot of “correctable codewords” and occasionally like 1 or 2 in the uncorrectable column.  I think this means that the packets are somewhat damaged or something so maybe my modem is just bad but I’m not entirely sure.

If you got any ideas lmk it would be appreciated thanks 👍


Best answer by SURFboard Moderator 30 November 2023, 01:09

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The logs are Values read by technicians from the internet provider end, since the logs are what the coaxial cable transmits and the log screen on the router is the translator so can be easily read by them, the coaxial cable is owned by the Internet service provider. If your Event Log is reporting a high volume of errors, this would indicate a potential CMTS signal issue. To troubleshoot these errors, we would like to note the current signal levels being used by your (sbg8300).

 There are some important things that should be within a specific range in order for the internet to work properly.

First, the SNR should be above 33 on all of them. The downstream power should always be between -15 and +15. The closer to 0 the better connection. Finally, your upstream power should always be between +45 and +51

On all of those values you should not have more than 3 decibels (or dB) between the lowest and the highest

By having the values in less than that, your device will have interrupted connection, slow or no connection at all.

The upstream values are not in accepted level so this needs to be checked again after reconfiguring the modem . so please do hard reset on the modem then check again the signal levels.
Even after resetting the modem if the values are same then it needs to be corrected and that can be done by the service provider or inform the ISP to re provision your modem.  Then monitor the connection for 24hrs and check the internet.