Cable Modem Ethernet Cable Bonding



  • Has anybody made use of their "bondable" ethernet ports on their so equipped cable modem to a LAGG'd pair on their pfSense box?

    What flavor a LAGG did you use?    My Motorola MB8600 is supposed to arrive tomorrow and Im just getting ready.

    http://motorolacable.com/documents/MB8600-DataSheet-09517.pdf

    http://www.arris.com/surfboard/products/cable-modems/sb8200/


  • Rebel Alliance Global Moderator

    So your internet connection is over a gig?  You have multiple devices to use this 1 and 1 pipe to your more than 1 connection?

    Or are you worried about port/cable failure and need a redundant connection?



  • I believe that, like the Arris SB8200, the link aggregation functionality will need to be enabled by the ISP. In Arris' case, I don't even think the functionality exists in their firmware yet. But like johnpoz mentioned, there's no real need for it yet since most cable ISPs using DOCSIS 3.1 are only offering 1 Gbps down (about 940-960 Mbps down after overhead).

    If from a redundancy standpoint, that's something else that would need to be enabled by the ISP… two different MAC Addresses connected to the modem (most ISPs only limit the modem to allowing one connected device, by MAC address). Of course, that would also allow two different IP addresses (or IP address blocks in the case of IPv6).

    So either way here, you're at the mercy of your ISP and when they decide to roll out such features, if they ever do.



  • Thanks for the replies!  :)

    Truthfully its more about testing the modem and reporting how well things go.  Im not quite up to the GIG club yet but much closer than in 2001 when I first signed up.  ;D


  • Rebel Alliance Global Moderator

    I really do not see the point of lagg on a cable modem.. If your over 1gig then the local side should be 10ge, or the up coming 802.3bz (2.5 and 5ge)

    Lagg would just be kind of pointless..  Its not 1+1=2, its 1 and 1 for a total of 2 combined across all sessions.  No single client would ever go above 1 gig.  And there is no real promise that even 2 clients would load share.. You need lots of clients talking to lots of different devices to spread the load across the lagged connections.

    With a cable "modem" and not a router even - means for example your pfense is going to be behind it.  So now you have a different layer 2 between the router and the clients so really only mac being seen is the pfsense mac - so when would you leverage the lagg?