MoCa issues with switch

[thebiz]

I have a moca network connection issue. I want to add more wired network ports coming from a moca adapter, so I connected a 5 port gigabit switch to my moca adapter. Here is the setup:

1. cable modem --> 2. netgear router --ethernet cable--> 3. yitong technology moca adapter --coax cable--> 4. coax wall jack --> 5. coax --coax cable--> 6. yitong technology moca adapter --ethernet cable--> 7. TP-Link gigabit ethernet switch --ethernet cable--> 8. Windows10 PC.

When I startup all devices, the network connections work fine for up to a random amount of minutes (anything from 5 to 60), then the connection drops on my PC with IP 192.168.1.2 – it cannot ping the router / default gateway with IP 192.168.1.1 anymore. I have tried several attempts at isolating the issue:

- When I reboot the PC, it gets an IP 169.254.40.12 which is not on this subnet. I assume that the PC assumes that the moca adapter is its network interface – but I could be completely mistaken.
- When I remove the switch, reboot the PC and connect it directly to the moca adapter via ethernet (removing the switch), it works again and doesn’t drop.
- When I start again from the beginning but configure a 2nd router as a switch (no DHCP, static IP on same IP range 192.168.1.x) and add it in the chain between 7. and 8., the same happens, i.e. connection drops after up to 5 minutes. Also, when I replace 6. with the access point and restart, same behaviour but I can still access the 2nd router.
- I have switched cables and tried different ports on the router
- I have tried different switches (TP-Link and Netgrear)

What this tells me is that there is something not quite right when connecting a switch to the moca adapter. Also, I don't think its related to the switch as I've read several posts that people generally have no issues adding switches to a moca network.

Is it possible that there are package collisions? Have you experienced this issue before , and if yes, how to resolve this?

 

[tannebil]

If everything works fine without the switch, the switch or the additional cable is the most likely problem. There is nothing wrong with your configuration as described.

Another, less likely, possibility is a duplicate address. DHCP servers and clients have ways to detect and work around the issue but they are not always 100%. Chances of the problem go up if you use any static addresses and are not super careful about static assignments and DHCP ranges.

Another possibility is a network loop although there’s nothing obvious in your description. Have you tested with nothing else connected to either switch?

Your description would seem to imply you have a piece of dedicated coax between your two MoCA units. Is that actually the case? If not, is everything between to two units MoCA compatible?

The 169.254.x.x is the address you get when DHCP fails to get an address.

 

[thebiz]

Hi tannebil,

thanks for your attention to this issue and helpful reply.

I strongly believe that its not the switch; after all, I tried 2 different, brand new switches from different manufacturers and it would be a big coincidence.

I will try your idea about the static IP devices today by removing them temporarily from the network and see what happens. One static IP device is a old router which I reconfigured as a wireless access point (by disabling DHCP), another is a NAS drive; the latter was always on as 192.168.1.10.

Yes, I tested with nothing else connected to the switch.

Regarding dedicated coax: I assume it is, but I cannot tell for sure myself as I'm living in an apartment building with around 10 units.

 

[degrub]

Do they have "green" ethernet ports ?
If so, try disabling that feature.
Assigning a static IP on the downstream devices (PC etc) may help as there will not be a DHCP request.

 

[thebiz]

Hi,
I removed the one device with a static IP which is always on, namely the NAS, from the network. I get slightly longer times without connection issues, but after about an hour, the same happens, i.e. it gets the 169.254.x.x address.
I've attached a home network diagram with IP addresses and DHCP scope of the router (with the NAS switched off). Do you spot anything wrong with this setup?

 

[tannebil]

In all likelihood you have a physical cabling problem. That place you labeled “wall” is likely the source because behind it are the coax cables and splitters that connect the cable outlets in your apartment. All splitters need to be MoCA certified (a huge percentage of already installed splitters are not) and you need to have a POE filter applied at the point where the cable company connects to the splitter (s) that feed the cable outlets in your apartment. This is likely to require the assistance of your super and your cable company (neither have much reason to want to help you) as you may not have physical access to the area and, if you start messing with stuff, you could very well screw up service for other apartments and that will make you hugely unpopular with everyone and might very well get you evicted.

Cabling and splitters for MoCA can be easy or hard. It all depends on when it was done, the way it was done, the familiarity of the person doing the work, and the control they have over the facility. A 10 unit apartment is likely to be a lot more complex than a house.

Right now, you are flying blind. You need to get a cable company tech who is familiar with your building’s wiring to figure out what needs to be done. If you can talk the cable company into helping, you might be OK but, in all honesty, I’d abandon MoCA as you just don’t have enough control over the cabling. Maybe you run a regular network cable inside the apartment instead or use something like Orbi to wirelessly bridge your network. You could also try a couple of the latest generation Ethernet-over-Powerline adapters although, like MoCA, if it doesn’t work out of the box, your chances of getting it working are low so buy from someone with a generous return policy.

 

[CaptainSTX]

In all likelihood you have a physical cabling problem. That place you labeled “wall” is likely the source because behind it are the coax cables and splitters that connect the cable outlets in your apartment. All splitters need to be MoCA certified (a huge percentage of already installed splitters are not) and you need to have a POE filter applied at the point where the cable company connects to the splitter (s) that feed the cable outlets in your apartment. This is likely to require the assistance of your super and your cable company (neither have much reason to want to help you) as you may not have physical access to the area and, if you start messing with stuff, you could very well screw up service for other apartments and that will make you hugely unpopular with everyone and might very well get you evicted.

Cabling and splitters for MoCA can be easy or hard. It all depends on when it was done, the way it was done, the familiarity of the person doing the work, and the control they have over the facility. A 10 unit apartment is likely to be a lot more complex than a house.

Right now, you are flying blind. You need to get a cable company tech who is familiar with your building’s wiring to figure out what needs to be done. If you can talk the cable company into helping, you might be OK but, in all honesty, I’d abandon MoCA as you just don’t have enough control over the cabling. Maybe you run a regular network cable inside the apartment instead or use something like Orbi to wirelessly bridge your network. You could also try a couple of the latest generation Ethernet-over-Powerline adapters although, like MoCA, if it doesn’t work out of the box, your chances of getting it working are low so buy from someone with a generous return policy.

Don't you mean MOCA filter and not POE filter? Probably even more important as Comcast's X6 box has built in MOCA and it is enabled by default. Even if you aren't a Comcast subscriber one of your neighbors might be and if they didn't install a filter then you have MOCA signals on your buildings coaxial wiring.

 

[tannebil]

Don't you mean MOCA filter and not POE filter? Probably even more important as Comcast's X6 box has built in MOCA and it is enabled by default. Even if you aren't a Comcast subscriber one of your neighbors might be and if they didn't install a filter then you have MOCA signals on your buildings coaxial wiring.

Dueling acronyms. POE filter gets for a MoCA point of entry filter while PoE is Power Over Ethernet. At least that's the way they get listed on Amazon.

I'm not sure if it makes an electrical difference as well. I would think that trying to send the MoCA signal gets attenuated if it isn't confined electrically a small to a small part of the cable plant. But that's out of my wheelhouse. All I know is that you are supposed to have one.

I can't remember if it was disable or enabled by default when I got mine. I used bonded adapters so I would have disabled it when I installed it.

 

[thebiz]

Thanks for your answer again. I'd like to understand more / add some input.

In all likelihood you have a physical cabling problem.

Is what I described a typical symptom of a physical cabling problem? What I don't understand though is, why does the connection stay up for sometimes up to 1 - 2 hours if its a physical problem? Couldn't it be some DHCP issue with leases getting reduced prematurely?

but, in all honesty, I’d abandon MoCA as you just don’t have enough control over the cabling. Maybe you run a regular network cable inside the apartment instead or use something like Orbi to wirelessly bridge your network. You could also try a couple of the latest generation Ethernet-over-Powerline adapters although, like MoCA, if it doesn’t work out of the box, your chances of getting it working are low so buy from someone with a generous return policy.

I'd really like to be independent of wireless, and Powerline doesn't instill much confidence. If it really comes down to that, I guess I'll have to settle for running regular network cable (at a price).

 

[krkaufman]

Have you tried using a different MoCA adapter than the Yitong? I know of another user over on TCF who had issues with their original Yitong MoCA adapters, and who ended-up working directly with Yitong's engineers testing alternate firmware. They eventually released a new adapter under the Kiwee Broadband name. (I'll see if I can find the original thread/info. edit: See here.)

You may also want to contact Yitong to see if they can help.