paul-d-ray/Cable_Modems_Routers.md

## Cable_Modems_Routers.md

      
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              Cable_Modems_Routers.md
            
          
Cable Modems

Motorola SB6120

This was in use from 2011/02 to 2019/10,
Default IP address = 192.168.100.1
Motorola MB8600

This was in use from 2019/10 to 2025/06.
Default IP address = 192.168.100.1
Arris S34

This was in use from 2025/06.
This supports Comcast split upload sppeds.  This allows 1 gig down and 300 meg up.
Default IP address = 192.168.100.1

Routers

Linksys WRT54GL

This was in used until 2014/10.
Was running Tomato.
Gateway IP = 192.168.1.1
Asus RT-AC68U

This router  in use starting with 2014/10, being retired in 2023/11 (9 years).
Last version of Asuswrt-Merlin installed was 386.12 (2023/09).
Added to the RT-AX88U Pro as a mesh client. This is in opposite side of the house from the RT-AX88U Pro.
Gateway IP = 192.168.1.1
Asus RT-AX88U Pro

This was installed on 2023/11/10 and updated to Asuswrt-Merlin
version 3004.388.4_0.
Gateway IP = 192.168.50.1


      ---
config:
  theme: 'dark'
---

graph TD

CA["SB6120 <br> 2011 - 2019"]
CB["MB6800 <br> 2019 - 2025"]
CC["S34 <br> 2025 - "]

RA(["WRT-54GL <br> Running Tomato <br> 2005? - 2014"])
RB(["RT-AC68U <br> Running Asuswrt-Merlin <br> 2014-2023"])
RC(["RT-AX88U Pro <br> Running Asuswrt-Merlin <br> 2023- "])

subgraph Cable Modem
CA --> CB --> CC
end

subgraph Router
RA --> RB
RB --> RC
end

CA -.-> RA & RB
CB -.-> RB & RC
CC -.-> RC


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This is for Asus WiFI routers.
Using asuswrt-merlin firmware
Router NVRAM

This is the code to check the free NVRAM memory.

The 386.10 firmware caused the NVRAM memory to be 90% to 95% full in the RT-AC68U.
This caused issues.
The 386.11  solved some of the issue by reducing max OpenVPN clients to 2 for RT-AC68U  due to lack of NVRAM on these models.
Router SSH

Open a SSH connction to the router.
The normal address is:
192.168.1.1
or
192.168.50.1
Show memory values

nvram show | awk '{print length(), $0 | "sort -n -r"}' | cut -d"=" -f 1 | head -n 20
Clear unused items from memory

for line in `nvram show | grep ^[^=]*=$ `; do var=${line%*=}; nvram unset $var; done; nvram commit
No results found