Posted: Wed Sep 19, 2018 20:05 Post subject: Setup Bonding for Link aggregation
Hi!
a few days ago I installed the r36808 on my WRT3200ACM but I'm not more familiar with DD-WRT.
I'm having difficulty in being able to understand how to setup a Link aggregation between the WRT3200 and my NAS.
The indications on how to configure the Link aggregation on the NAS are clear, QNAP provides a guide.
While what settings to enter on the router aren't clear, I think I must to set something in: Setup -> Networking -> Bonding where to select 802.3ad.
If this is correct, what else should I enter?
eth0 and eth1 to which Lan ports of the 4 available match?
Currently the NAS is connected to the Lan1 port of the router which in turn is connected via WAN port to the modem.
Can someone give me some more precise indication please? _________________ WRT3200acm - r41491
Link aggregation as used for something like a NAS with dual LAN ports is more of a function of the switch ASIC than it is of the routing. Seeing as most of the routers have pretty basic switch ASICs in them, you're probably not going to have a whole lot of luck with this. You're probably better off to get a separate managed switch that supports link aggregation, put all your devices on that managed switch and just use the router to do routing.
If I understand well, Link aggregation is implemented at the hardware level through ASIC technology.
So if originally the router isn't equipped with this function can't be activated via FW DD-WRT or other type of software? Or would you need a specific update that is not currently implemented by DD-WRT? _________________ WRT3200acm - r41491
Are we sure none of the routers have a slightly upgraded switch ASIC? For instance the old Netgear GS108E switch supports a single LACP link - maybe 2 port only. (Nope not tearing its welded metal case to find the chip number.) That chip is probably cheap now. In general reduction in total ports and in number of supported aggregated ports will greatly reduce the number of gates. The basic equation for switch networks is NxN where N= number of ports.
On ordinary dumb layer 2 switch as in the cheapest wireless routers...
Failover link aggregation (no bandwidth gain just spare links) should be something possible by manipulating STP and port disable at worst.
Layer 2 switch to switch bandwidth aggregation is either impossible with basic ASIC due to network loops or not cost effective. Because the only avenue I can see is a device at the other end that is smart enough to convince dumb ASIC in home wireless router that reverse path on second port is not viable (too costly, etc) alternative path so loop does not form. That means $$$ technical (skill x time) and/or $$$ equipment which suggests buying a commercial router with excellent OEM link aggregation as a cheaper path than DD-WRT and home wireless router.
Layer 3 IP bandwidth aggregation might not be completely impossible but it would involve some tricky ARP deception and faking link negotiation for any dynamic aggregation.
I note that the only DD-WRT documentation we have on that bonding feature seems to be an example for failover.
Not encouraging as there is a significant need for a single bandwidth aggregation link on home/SOHO wireless routers to feed NAS/local server data to 802.11ac and faster wireless clients. At least until 10Gbps ports on home/SOHO wireless AP/routers becomes reasonably priced.
Also note that if I remember right none of the common link aggregation standards support single connection speeds faster than a single port in the aggregate. Its more about feeding multiple high speed connections to the same resource.
FYI the switch chip my old ASUS RT-AC66U is a BCM53125
The Roboswitch line of products does support Link-Aggregation per 802.3ad according to ROBOSwitch Selection Guide on Broadcom site.
BCM53125 was released in 2010 and still active as are many of its chip family. So the hardware support has been out for a long time.
It more a question of if DD-WRT software running on main CPU programs the ASIC command registers to support that.
HOWEVER... the bandwidth going to wireless from wired ports is limited to 1Gbps since the internal port which connects from the switch chip to CPU/wireless bridge are only 1Gbps. To see full speed gain the load from link aggregation would need to be split more or less evenly between switching ports (direct switch action) and routed/bridged wireless traffic going through CPU/bridge.
Truly there is not much point in running bandwidth aggregation to a wireless router with the internal 1Gbps bottle neck going to wireless. All that non-wireless traffic would better be sent to an exterior switch for extra speed, greater reliability and far less complexity (especially when you take into account actual HP documentation vs DD-WRT scattered ad hoc wiki and forum fare).
FYI A used HP ProCurve 2810-24G can be obtained on eBay for $40 bucks. The only issue being a few extra watts and moderate noise (due to rack mount design). At least 8 LCAP links possible and far more than 2 port aggregates possible. Fully loaded I think it is 80W off top of my head. Latest firmware greatly reduces noise. But put it in a ventilated foam lined box would probably make noise acceptable regardless.
Truly there is not much point in running bandwidth aggregation to a wireless router with the internal 1Gbps bottle neck going to wireless. All that non-wireless traffic would better be sent to an exterior switch for extra speed, greater reliability and far less complexity (especially when you take into account actual HP documentation vs DD-WRT scattered ad hoc wiki and forum fare).