multiple Powerline networks attached to same router...this should work right?

[Steve Sybesma]

I'm not finding a clear answer on this but it seems like this is very possible and doesn't break the rules on how PL should work in any way I can conceive of.

I have SIX ZyXEL PLA5456 Powerline adapters which adhere to the HomePlug AV standard.

I know that multiple PL networks are allowed with these devices so that you can isolate the traffic on the separate networks. This is good if you have two separate subnets and don't want the devices on different PL networks talking to each other (bypassing the border between the subnets established by the upstream device) which could happen if all the adapters were on the same PL network.

HOWEVER, I want to have separate PL networks which are connected to the same router and all would be on the same subnet.

The purpose of doing this is that I want to spread the load between the ports on my router so all PL traffic doesn't have to go through only one router port, which in my mind could damage it.

I should add, I have over 30 devices attached to my home network which pull an IP address and most are not wifi. At each PL node, I have a smart switch to which about 4 devices are attached. To me, that is too much traffic to share one router port.

Is this permitted under the standard?

It seems like it would be because the traffic from each PL network is all connected together at the router so it doesn't matter if the PL networks cannot talk directly to each other. I intentionally want the three PL networks to talk to each other through the central router.

Thanks!

 

[L&LD]

You are worried for no real reason. 30 devices is not an excessive load on a router's 'ports'. Even through a single port. Even if they were all maxing out the throughput possible by the very inefficient PLA adaptor(s) you're using.

Stop worrying and don't fix what isn't broken.

 

[Steve Sybesma]

You are worried for no real reason. 30 devices is not an excessive load on a router's 'ports'. Even through a single port. Even if they were all maxing out the throughput possible by the very inefficient PLA adaptor(s) you're using.

Stop worrying and don't fix what isn't broken.

Well, technically the ZyXEL VSG1432-B101 that I have which cannot handle that many connections is broken. The router is completely fried and cannot find most devices on my network connected to Ethernet. Most of what works on it anymore on my home network is through wifi.

I don't have enough control over that device to (for instance) edit the configuration file directly, so I don't know if there's junk hidden in the configuration or what.

It does lose its configuration and gets so bad I have to reflash the firmware and restore the config to get it working again. Doing this about twice a month now just to keep it limping along.

The problem really started once I put enough devices onto my home network. Somewhere after 25 devices I think.

Regardless of what you say, very few people have 30+ devices on their home network. That is a lot for a home user.

I'm going to try my experiment to load balance and see if this works once I get my new modem, which at this point is probably going to be DrayTek 2860ac. This seems to have a more robust router built into it than any of the consumer-grade stuff. Has a two-year warranty which is better than any consumer grade stuff except ZyXEL.

I'm into learning how to maximize performance on my home network...I'm not a new user.

The PLAs I have work a lot better than the old school 80mbps or 200mbps ones you might be familiar with.

When my Ethernet network was functioning before the router started to die, the speeds were much better than wifi, which I really don't like anyway.

They're rated at 2000, which means in practice they're probably running about 1/3 of that speed. Again, still much better than wifi, especially considering all the walls and floors in my multi-level townhome that mess with the signal.

 

[sfx2000]

HOWEVER, I want to have separate PL networks which are connected to the same router and all would be on the same subnet.

This is entirely possible - one can have multiple PLC networks on a single LAN, as PLC is all lower layer traffic...

the challenge is that PLC, like wifi, is a shared medium, and having multiple PLC's on the same grid will impact overall bandwidth...

Likely better to keep all the PLC's together as one group...

 

[Steve Sybesma]

I'll try the experiment and let you know how it goes. My theory is that there would be no appreciable change by dividing up the traffic on each PLC network. Three PLC networks carrying 1/3 of the traffic each versus one carrying all the traffic. Approximately the same amount of data on the powerline. I'm not expecting any gain there or doing it for that reason. The main benefit would be not burning out the Ethernet port by forcing everything to go through only one of them. I'm trying to spread the load. Honestly think that's what happened with my VSG1432 from ZyXEL. Just ordered a DrayTek Vigor 2860ac today (which is overkill for most households, except mine because I have a lot of devices divided up on four 8-port smart switches).

 

[thiggins]

How are you separating the Powerline networks? The only way I know is to set different encryption keys.

But as SFX points out, all powerline adapters share the same bandwidth. Unlike Wi-Fi, you can't set it to specific channels to gain more bandwidth.

 

[Steve Sybesma]

I never said I was trying to gain bandwidth. I don't care about bandwidth. I expect it will be a wash and be approximately the same as before. All I care about is spreading the load between the Ethernet ports on my router (which at this point will be a new one because the old one's routing ability is damaged).

 

[Samir]

You are not understanding some fundamental concepts behind the technology you're using. And hence you're attempting to find a non-existent solution for your problem.

I have over 40 items on our home network. Our home network connects to our business networks via site-to-site vpn tunnels. An steady amount of traffic is on our lans and wans at all times. It's not common, but it exists a lot more than people think.

You really shouldn't be having issues like that with the Zyxel unless you're constantly utilizing all of your Internet bandwidth--then the router may be getting taxed. Zyxel has excellent tech support--I'd call them about the issue with the router and see what they can determine.

As far as the powerlines, plugging in one to your router will be enough. There is no way to 'overload' a network port. It always operates at the same speed--it's just busier or less busy. Plug in a single powerline to the router--that will be fine (even if you had 48-port switches attached to each of your powerlines on the other side).

You could have a particular device on your network causing problems. Luckily, this is easy to diagnose. Unplug one device at a time for a few days and see if the Zyxel stays okay for a longer time. If it does, then whatever device you unplugged might have been the source of the problem.

 

[Steve Sybesma]

I wouldn't say I don't understand fundamental concepts unless you understand what I'm trying to do.

(BTW, what equipment are you using that's not blowing up after less than 2 years with all the devices you have? Guarantee you're not using consumer-grade stuff with that much of a network unless you just happen to be very lucky!)

Now, my all-in-one DSL router is definitely fried and out of warranty. I cannot see other Ethernet-connected devices anymore unless they're on the same switch. There's no question about that. So that has to be replaced no matter what.

The NVRAM in it is so bad that it loses its configuration and even the firmware is lost so I have to reflash it and restore the configuration about once every other week. That's not something you can fix with a tech support call and I don't need tech support to tell me that. It's been that way since about July and I made no errant changes to the configuration so I would expect that. I'm very particular about how things get changed and how accurate the information is that goes into each one. Incidentally, I don't allow all the IPs to be assigned via DHCP. I reserve all the IPs on my home network and make them static in whatever devices allow that. The thing about the configuration file I don't like is that I cannot directly edit it (I think it's LZW compressed/encoded XML).

I feel the quality of router in the ZyXEL was the issue (obviously it didn't last very long).

One other point. The ports on that old router are only 100Mbps. My new one coming later this week has 1Gbps ports.

What I simply want to do as an experiment is to see if I can divide the load up between 3 PL networks on three Ethernet ports. Since I have the extra ports to spare, and I'm not expecting improvement in bandwidth (that's not the reason I'm doing it), I think it's a smart idea to make use of more of the ports that are otherwise wasted and have more ports share the work rather than only one port carry the entire load.

All I care about is whether the Powerline standard allows that to take place. I'm not expecting performance gains. What I expect to gain is reliability and a longer-lasting piece of equipment.

Aside from the real issue with the malfunctioning DSL router, there could be malfunctioning device. However, if there is, that's not the reason why I'm having the serious issues with the router...that is separate.

I don't know of a piece of software that is easy to use that can tell me what device is misbehaving on the network (throwing out garbage to the router and confusing it, for instance).

 

[Steve Sybesma]

I have learned that very often I put out an idea and it's slammed but sometimes it's interesting to find out if something does what I think it should be able to do (in this case multiple PL networks attached to the same router). If it works because someone like me was brave enough to test it and find out, perhaps someone finds a better use for it.

Maybe you're right and the combined traffic on my home network feeding into one port won't ever damage it. However, why push it and not spread the load? I hate buying new equipment every two years.

 

[Samir]

Actually, we ran a very outdated netgear fvs114 for over a year. It isn't consumer gear, but the line between consumer and small business gear is a bit blurred at the $100 mark these days. Currently we run a very outdated watchguard as well as some netgear fvs318ns. Not cutting edge by any means. The watchguard's download tops out at 30Mbps.

I get what you're trying to do. I've done this same thing on gear that's failing just to see what works.

You should be able to change the encryption key on each set to make 3 independent PL networks. However, as soon as you plug in all three into the switch, you might have some problems. I'm not sure if you can have multiple wired connections from PL adapters to a core router without creating network loops. You could try it because the worse case scenario will be a packet storm and will effectively crash your network. And once you unplug two, everything would go back to normal.

Best case scenario, you'll actually have what you want--3 PL networks feeding into your main LAN over 3 ports on the Zyxel's switch vs just one port. And this may help your dying Zyxel or it may not. My guess is that it will not, but I've seen stranger stuff work when things have gone defective. Good luck and let us know how it goes.

 

[sfx2000]

I'll try the experiment and let you know how it goes. My theory is that there would be no appreciable change by dividing up the traffic on each PLC network. Three PLC networks carrying 1/3 of the traffic each versus one carrying all the traffic. Approximately the same amount of data on the powerline. I'm not expecting any gain there or doing it for that reason.

PLC is a scheduled protocol - so whether one has six in a single group, or three sets of 2 each... it's easier to keep them all as a single group unless there is a compelling reason not to - and the benefit of the single group is really two fold - easier admin and monitoring, and the PLC nodes will coordinate together.

The main benefit would be not burning out the Ethernet port by forcing everything to go through only one of them. I'm trying to spread the load.

Fair enough - just note that pushing a lot of traffic thru an ethernet port does no harm to that port... could be other factors at play here - ports can die, but generally it's because of an electrical fault somewhere.... could be bad caps as an example...

Honestly think that's what happened with my VSG1432 from ZyXEL. Just ordered a DrayTek Vigor 2860ac today (which is overkill for most households, except mine because I have a lot of devices divided up on four 8-port smart switches).

The vigor is a nice unit - decent quality, good performance - should be a good upgrade to your network...

 

[Steve Sybesma]

Hello Samir,

I became concerned that the amount of devices I kept adding to my home network using the ZyXEL VSG1432 was the problem that caused it to fail. Maybe not...maybe the quality of the router in the all-in one wasn't very good (kind of jack of all trades, master of none on quality). I got the idea when I was in the market for the new unit that I was going to see if I can preserve the new DrayTek's life by not pushing it too hard. That was the motive behind all this.

I know I can change the encryption key so I will have 3 separate PLA networks. I think it will work because changing the keys prevents the PLAs networks from talking to each other before the signals reach the router. Once inside the router, then it's normal packet (level 3) traffic. Keep in mind I'm not plugging the three PLA networks into a switch but a router (not just semantics, right?). Switches are level 2 and so are the PLAs (I definitely understand how combining those three in a switch would be a problem). Plugging into a Router (level 3), I'm not dealing with a level 2 issue anymore. My theory is that there won't be any traffic loops if it's true the PLA networks really are isolated outside the router.

I'm trying to understand this more deeply regarding potential traffic loops:

If a 'frame' from the 1st PLA network enters the 1st router port, gets encapsulated into a packet, then gets spit out the 2nd router port to the 2nd PLA network, the packet encapsulation gets stripped at the 2nd PLA adapter and the frame that used to be 'keyed' to the 1st PLA network is now 'keyed' to the 2nd PLA network. I don't see how that frame can 'leak' back to the 1st PLA network on the powerline (bypassing the router) since it's now supposed to be 'keyed' to 2nd PLA adapter. In theory that same leakage should occur on entirely separate networks where the powerline is still the common medium shared by the two PLA networks, because (as far as I know) the traffic passing the PLA adapters are only identified by how the PLA adapter identifies them, not by any higher level protocol that it would not know about.

Anyhoo...if any of that sounds incorrect let me know. I stretched myself a bit there.

 

[Steve Sybesma]

Hello SFX2000,

I agree with you that it's simpler to keep all the PLAs on the same network.

Thinking deeply about how this works though...all PLAs on one network (as I still have it now, regardless of the broken router situation):

All the traffic between the PLAs still has to come into/out of the router and be divided/combined at the master PLA to the correct PLA network. So, I don't save any extra movement of traffic as far as avoiding traffic to the router since the nodes cannot directly communicate through the master PLA anyway. What I'm doing is 'widening' the path into the router by giving it three lanes instead of one. There could be a loss inside the router due to the extra overhead of 3 ports working instead of 1, which offsets any gain due to the wider path. I can see that. I honestly don't know how the loss/gain would be skewed one way or another. What I probably still gain is less wear and tear (spreading out the generated heat?). If you consider the fact that the total traffic passing back and forth through the Master PLA (rated 2000Mbps but in reality, the potential is about 1/3 of that) at certain times could be greater than the 100Mbps that was the maximum the old router ports could accept, it's putting a frequent enough strain on it that is often near its capacity and sometimes trying to go over. 40Mbps download/5 Mbps upload internet, plus the combined back and forth traffic from the downstream devices (especially if I'm doing operations between devices to transfer data)...pushing 100Mbps at certain times is conceivable.

With the new router, I have all 1Gbps ports. So, with 10 times the capacity...I concede one port isn't even close to a strain like it was on the old router.

I'll read up on that subject though (Can sustained high traffic through a single port cause damage?), since you got me wondering.

The other thing (as I mentioned earlier)...I have to find a simple to use app that will point to any bad device spitting a lot of junk onto the network.

I've flirted with Wireshark a bit, but it's a learning curve. I have to figure out how to set it up to flag a misbehaving device. That would be very useful.

 

[sfx2000]

Perhaps you're overthinking things... and that's ok...

Use as many ports as you need - PLC's are nice, but a CAT5 cable is always better - ports don't really wear out, trust me, they don't...

At the end of the day - it's your network, and whatever works, that's ok - simply put - and the best advice I can provide is keep it simple/

 

[Steve Sybesma]

Yep, maybe so. I do a lot of thinking and don't claim it always makes perfect sense.

I'm changing my current config where I used to have 1 master PLA in the living room, then node PLAs in the living room, office, bedroom and basement with ZyXEL GS1900-8 managed switches attached to each node PLA. That's 5 ZyXEL PLA5456s (plus I have a spare because I bought three sets of two and wanted a spare). The new configuration would be 3 master PLAs in the living room, then no node in the living room (substituting CAT7 because the switch is only 10' away and most of the higher bandwidth stuff is in the living room anyway), then node PLAs in the office, bedroom and basement of my townhome. It would be expensive in this place ($1,000s) to properly install Ethernet cabling in the walls to get to the other three areas (why I chose PLA to start with). I'll run the CAT7 in the living room where the wall meets the ceiling to get it over to the switch.

Once I get that done, I think I'll have a dynamite home network.

Now I just have to learn Wireshark. It's possible I could have a bad device somewhere, but that doesn't change the fact my router is nearly dead.

 

[Samir]

Hello Samir,

I became concerned that the amount of devices I kept adding to my home network using the ZyXEL VSG1432 was the problem that caused it to fail. Maybe not...maybe the quality of the router in the all-in one wasn't very good (kind of jack of all trades, master of none on quality). I got the idea when I was in the market for the new unit that I was going to see if I can preserve the new DrayTek's life by not pushing it too hard. That was the motive behind all this.

I know I can change the encryption key so I will have 3 separate PLA networks. I think it will work because changing the keys prevents the PLAs networks from talking to each other before the signals reach the router. Once inside the router, then it's normal packet (level 3) traffic. Keep in mind I'm not plugging the three PLA networks into a switch but a router (not just semantics, right?). Switches are level 2 and so are the PLAs (I definitely understand how combining those three in a switch would be a problem). Plugging into a Router (level 3), I'm not dealing with a level 2 issue anymore. My theory is that there won't be any traffic loops if it's true the PLA networks really are isolated outside the router.

I'm trying to understand this more deeply regarding potential traffic loops:

If a 'frame' from the 1st PLA network enters the 1st router port, gets encapsulated into a packet, then gets spit out the 2nd router port to the 2nd PLA network, the packet encapsulation gets stripped at the 2nd PLA adapter and the frame that used to be 'keyed' to the 1st PLA network is now 'keyed' to the 2nd PLA network. I don't see how that frame can 'leak' back to the 1st PLA network on the powerline (bypassing the router) since it's now supposed to be 'keyed' to 2nd PLA adapter. In theory that same leakage should occur on entirely separate networks where the powerline is still the common medium shared by the two PLA networks, because (as far as I know) the traffic passing the PLA adapters are only identified by how the PLA adapter identifies them, not by any higher level protocol that it would not know about.

Anyhoo...if any of that sounds incorrect let me know. I stretched myself a bit there.

I agree on the jack of all trades devices having tradeoffs, as it may be in the case of your Zyxel. I think the Draytek
will be more than able to handle everything.

It's fascinating what you're trying to do, and it actually does help like how hubs work vs switches.

Back in the early days of Ethernet, you had hubs, which took a packet that was being transmitted by a system and broadcast it out to everyone, with only the receiving system using it. Every system on the network did this which caused a problem during times of high traffic since two systems can't transmit at the same time. When that would happen it would be a 'collision'. Collisions used to be quite common on busy networks.

Then along came the switch. The switch remembers which port what mac addresses are plugged into. So when a system is transmitting, the switch only sends it to the port that has that mac. (In the case of cascaded switches it remembers all the mac addresses in the cascaded switches.) Because of this multiple systems could transmit at the same time without collisions and hence system could run at full speed.

So now let's apply some of that to what you are doing with the PL adapters. Normally the PL have one single network, and hence one collision domain. When you segment the PL network into three networks, you essentially have created a 'switch' of sorts using the PL adapters. The one thing to note that's different than a normal switch which increases the aggregate bandwidth, is that in the PL network, all the different PL networks still share the same bandwidth pool.

So once you have three different powerline networks that cannot communicate with each other, the only way each of those networks can communicate with each other is via the switch on the Zyxel. Essentially, this would take any previous intra-PL network transmissions and force them to go through the Zyxel's switch if they are now between different PL segments. Switching isn't taxing at all, so even a badly performing Zyxel should handle this easily. But routing these (over the Internet or otherwise) may more taxing or less taxing or maybe the same--only a test will tell.

What's interesting about what you're trying to do is that it addresses something that may not even be an issue if it's been addressed in the PL architecture, or may actually be a pretty big issue that's never been considered--collisions on a PL network. If in fact there are collisions on a PL network, segmenting like this can reduce the number of collisions, and while it cannot increase the PL network bandwidth, segmenting can increase the usable bandwidth since collisions would be reduced.

I think your assessment on what happens to the frames is spot-on. And let me apologize for thinking you didn't know this stuff because you sure do grasp it very quickly if you didn't already know it.

 

[Steve Sybesma]

Samir,

The only part of this that is not straight in my mind is that you're saying the ZyXEL has switch ports. I thought they were router ports, no?

I guess the correct definition of a router port would be if each port could be isolated to its own network/subnet rather than all ports being forced to be on the same one? I never bothered to check if multiple networks/subnets are allowed on that (so that each port can be assigned its own dedicated address range). I think not, so maybe that means its not a 'true' router unless the two networks are merely the WAN and the LAN. So, what I have is more like a bridge instead of a router and it merely includes switch ports, I guess. Sorry, I am showing my partial ignorance.

 

[Samir]

So the router as we know it is actually two things--a router and a switch. A router as it was back in the day only had two ports--one for one side and one for the other. You made routes in the routing table and the router routed.

The Internet changed all this as all of a sudden everyone needed a router. Then throw in NAT and a DHCP server and suddenly you could have a lot of systems on one side of the router very easily. But there was a problem--not enough ports. So a cheap 4 port switch became a standard add-on to the router as we know it today. This is why you can simply disable the DHCP serer and change the IP on a router and just use the lan ports as a regular unmanaged switch (in fact I'm using an old router as a switch right now.right now--an old Netopia dsl router left over from some business dsl lines that we disconnected eons ago).

So your Zyxel has a 4 port switch built-into the router.

So taking what you mention about each port having its own network, that's where VLANs come in. VLANs are Virtual LANs, where you can assign each port to act like its own network. Each port can have its own dhcp server, subnet, IPs, etc, and be separated from the other VLANs even though they're on the same physical switch. I haven't checked the specs of the Draytek, but it may support VLANs.

You can also have VLANs that aren't port based, but I don't have any experience with those.

 

[Steve Sybesma]

OK, gotcha...that sounds completely correct to me now. VLANs are basically a 'network' that exists on level 2 (MAC), instead of level 3 (network) so the broadcast traffic from a VLAN is therefore not filtered out by the router from crossing over to another network which would normally be the case.