SOLVED Ethernet intermittent

[Glorious1]

I'm a real newb when it comes to networking. And I'm not sure this is strictly FreeNAS related, but it might be.

I have a Motorola cable modem/router with 4 ethernet ports and wifi. Generally I've had FreeNAS connected to the router via LAN1 and the dedicated IPMI port, but IPMI also works over LAN1 if the IPMI cable is not connected. Client computers also connect to the router. It has always seemed to work well.

Lately I've noticed when I connect my laptop to ethernet, and turn off wifi, any kind of connection to FreeNAS can become intermittently slow, then disconnect completely. This applies to SSH, AFP, and HTTP.

There is no such problem using wifi. I'm not sure if there is a problem over ethernet to the internet, but if there is it is not as obvious. I've tried connecting another computer to ethernet the same way and also saw the problem. I've changed cables and it makes no difference. So hopefully I've ruled out client computers and cables.

Is there a way to connect my laptop straight to FreeNAS, without going through the router? When I've tried that I get no connection of any kind. If I could do that, I could maybe see if the problem is the router or the server.

 

[Glorious1]

A bit of progress - I was able to hook a cable directly from my laptop to the server. Apparently the tricks are
1. The wifi has to be switched off on the laptop, and;
2. The server cannot also be connected to the router.

Does that make sense? Or am I missing something?

Anyway, so far, the ethernet coms have been stable with a direct hookup. If this persists, my suspicion will be focussed on the Motorola modem/router. While fooling around, I've already noticed that the top ethernet port on the router doesn't light up when you plug something into it. Plug it into one of the others and you get flashing LEDs. Could it be if one port is dead, the others are compromised?

 

[nojohnny101]

Sounds like you have done some logical deduction in getting to the cause of the problem. Based on information you have provided, it sounds like it is the modem. Are is that motorola modem also serving as your router? If it is, please for the love of pete get a proper separate router than your cable modem (and please tell me you're not renting from the ISP).

Just one more test case I thought of, you could try different port combinations. If you think that port 1 is bad (no lights) then plug your laptop into port 2 and the freenas box into port 3. Or you could plug freenas into port 4 and you laptop into port 3. I would try all combinations that avoid the port that you suspect is having problems.

While you're at it I would contact your ISP and tell them a port on it is bad and then get them to replace it with a unit that just is a modem, then get yourself an off the shelf proper router or better yet you can build a dd-wrt router.

 

[Glorious1]

Thanks for the feedback. Yes, the Motorola is serving as both modem and router. It's all there is between my computers and the intertubes. I used to have separate, but diagnosing problems and resetting was a very involved ritual, so it seemed easier to have them integrated. I own this, no renting from ISP.

However, I would expect if I ask the ISP to provide a modem, I would be renting monthly for it.
It does seem like most of the good routers do not have cable modems.

I will try some further tests as you suggested. As it is a lot of cause and effect is just confusing me.

 

[pschatz100]

While the problem could be your cable modem/router, it might also be that your network is not configured well. How do you have your network set up? Are you using DHCP from the router? What is the range of auto assigned addresses? What are the IP addresses being assigned to your computers?

 

[Glorious1]

Some devices are using DHCP (mostly phones and an iPad), while others have self-assigned IP addresses.

• The router/gateway is 192.168.0.1.
• DHCP starts at 192.168.0.2 and can assign up to 50 addresses (it actually was 120, which IS a bad configuration, though I'm sure it never got to the triple digits where the self-assigned IP addresses are. Anyway I just set it back to 50.).
• FreeNAS and its IPMI and jails, 2 macs, and a wireless printer have self-assigned IP addresses starting at 192.168.0.100.

Hopefully that makes sense?

 

[tvsjr]

Unfortunately, you're likely discovering that consumer-grade crap is just that... crap. I'd start by getting a decent 8-port switch (the HP 1810-8 being a favorite choice of mine) and see what happens.

 

[Glorious1]

Unfortunately, you're likely discovering that consumer-grade crap is just that... crap. I'd start by getting a decent 8-port switch (the HP 1810-8 being a favorite choice of mine) and see what happens.

Thanks. I'm confused by the terms switch, router, hub. So switch is what I want? Presumably I could hook it to the Motorola and set the latter in some mode so it's acting like a modem only?

 

[nojohnny101]

You are correct that, I thought you were renting from the ISP so getting them to replace it would have been free but I understand now.

What you could do as @tvsjr mentioned is just get a relatively inexpensive unmanaged switch. This means that the switch doesn't take part in any control over the network, its just passes through connections. This would give you a bunch of reliable ethernet ports to plug everything into and then if you don't want to get a separate wireless router, then you could just continue to use the modem/router combination to manage your network settings and handle your wifi.

Presumably I could hook it to the Motorola and set the latter in some mode so it's acting like a modem only?

your motorola would have to still handle the DHCP duties. But I suspect you have a bad ethernet port, just my opinion based on what you described.

 

[Glorious1]

What you could do as @tvsjr mentioned is just get a relatively inexpensive unmanaged switch. This means that the switch doesn't take part in any control over the network, its just passes through connections. This would give you a bunch of reliable ethernet ports to plug everything into and then if you don't want to get a separate wireless router, then you could just continue to use the modem/router combination to manage your network settings and handle your wifi.

But the new switch would have to be plugged into one of the 4 potentially unreliable LAN ports on the Motorola, right?

your motorola would have to still handle the DHCP duties. But I suspect you have a bad DHCP port, just my opinion based on what you described.

You're not talking about an ethernet port here? DHCP port is something internal? Implication being scrap the whole Motorola unit?

 

[tvsjr]

So, there are three components to your existing Motorola gateway.

Modem - A contraction for MOdulator/DEModulator. This takes digital data and puts it on an analog medium, typically a cable modem or DSL line (or an analog phone circuit).
Router - This device handles traffic from multiple computers and allows it out to the Internet through a single IP address. It typically also includes basic firewall functionality that prohibits inappropriate traffic inbound.
Switch - This device lets multiple Ethernet devices communicate between each other.

DHCP is a service, Dynamic Host Configuration Protocol, that assigns IP addresses to the systems on your network. In your case, DHCP is a service running on the gateway.

Your "gateway" is all 3 things in one... and, as we all know, jack of all trades, master of none. These units have continuously disappointed me. In my experience, it's best to have all three separate. Personally, I have a modem (cable), a router/firewall (PFSense), and several switches.

I would start by buying the switch. Connect everything on the gateway's LAN ports to the new switch. Connect a patch cable from one port on the switch to a port on the gateway. This will allow everything to keep working, but prevent the gateway from having to be a switch. Traffic from a local system to your FreeNAS box would go through the switch, but would never be seen by the router. That would tell you if the gateway is a problem, while not impacting the rest of your network.

 

[nojohnny101]

Sorry @Glorious1 I meant ethernet, So I have edited the post above.

I think you need to eliminate all doubt or confirm that your current modem/router is the problem. Follow what @tvsjr said and this will give us some clue. Did you also try different combinations of ports as I suggested? Thinking about this now, if you confirm some ports are good and some are bad, I wouldn't trust any of the ports.

 

[Jailer]

Get a cheap switch and hook one LAN cable from your modem/router to the switch and everything else to the switch. All the LAN traffic will pass through the switch and if the modem is culprit it won't interfere since it won't be passing any traffic except internet traffic from your LAN.

 

[Glorious1]

Ok, I'll go for a switch and see what happens. The HP suggested by @tvsjr doesn't seem to be available anymore. After reading up, I'm looking at this Netgear ProSAFE GS116NA 16-Port Gigabit Ethernet Switch (GS116NA). ($79)

• 16 ports - I read some advice to go big on ports as more and more devices are ethernet-connected.
• 1 Gbps
• Total bandwidth 32 Gbps
• QoS
• unmanaged

Any dissenting opinion will be considered. Thanks.

 

[Jailer]

Looks good. I picked up a cheap TP link un managed 24 port and it's been serving me well.

 

[pschatz100]

Some devices are using DHCP (mostly phones and an iPad), while others have self-assigned IP addresses.

• The router/gateway is 192.168.0.1.
• DHCP starts at 192.168.0.2 and can assign up to 50 addresses (it actually was 120, which IS a bad configuration, though I'm sure it never got to the triple digits where the self-assigned IP addresses are. Anyway I just set it back to 50.).
• FreeNAS and its IPMI and jails, 2 macs, and a wireless printer have self-assigned IP addresses starting at 192.168.0.100.

Hopefully that makes sense?

Actually, it doesn't really matter how many addresses are available via DHCP. The key thing is that the devices with the static IP's must be outside the range of the allowed DHCP addresses. By reducing the DHCP range to 192.168.0.2 through 192.168.0.51, and keeping your static IP's above 192.168.0.100 then you are now OK in this regard.

Have you made certain that your gateway and DNS Nameserver addresses are configured properly on all your devices? The devices that are getting their IP adresses via DHCP will have this configured automatically, but you have to set these parameters yourself on the devices with static IP's.

Unfortunately, you're likely discovering that consumer-grade crap is just that... crap. I'd start by getting a decent 8-port switch (the HP 1810-8 being a favorite choice of mine) and see what happens.

This would not be a good choice for a home network. A simpler un-managed gigabit switch is appropriate for a home network.

While fooling around, I've already noticed that the top ethernet port on the router doesn't light up when you plug something into it. Plug it into one of the others and you get flashing LEDs. Could it be if one port is dead, the others are compromised?

It certainly is possible for a port to be bad. It happened to me on a cable modem a couple of years ago. In my case, the other ports were OK.

So what do you do? I would not be in a hurry to purchase a switch. I would verify that each and every device on your network is configured properly. I would also avoid using the port on your cable modem that appears to be bad. How many wired devices are you networking? From your description it is not clear.

 

[Glorious1]

Have you made certain that your gateway and DNS Nameserver addresses are configured properly on all your devices? The devices that are getting their IP adresses via DHCP will have this configured automatically, but you have to set these parameters yourself on the devices with static IP's.

The gateway/router was set correctly in all the devices with self-assigned IP. The first two DNS servers were set the same for all (google, 8.8.8.8 and 8.8.4.4), the 3rd varied. I made them all uniform. The printer has the gateway set, but I don't think it has DNS settings. It is only on wifi.

It certainly is possible for a port to be bad. It happened to me on a cable modem a couple of years ago. In my case, the other ports were OK.

That top port definitely does not light up at all. However, it does transfer data, maybe it's just an LED out.

So what do you do? I would not be in a hurry to purchase a switch. I would verify that each and every device on your network is configured properly. I would also avoid using the port on your cable modem that appears to be bad. How many wired devices are you networking? From your description it is not clear.

There are probably 10 or so devices networking. Only two are permanently wired to the modem/router/switch, the FreeNAS server and a Mac mini that serves as a home theater PC, with wifi off. I did have the FreeNAS IPMI wired in separately, but that doesn't appear to be necessary. I occasionally connect one or another computer to the network by wire for heavy backups or file transfers.

So at the moment, I can really get by with just 3 ports. But if I replace the old TV or similar, I would need more.

At this point, the problem seems to be more or less fixed or less severe. I'm not sure whether it was just avoiding that bad port or other config changes. I'll continue testing to see if it's really as good as a direct connection to FreeNAS.

 

[pschatz100]

@Glorious1: in one of your earlier posts, you commented that the router initially had DHCP set for 120 IP addresses, but your static IP's were starting at 192.168.0.100. As part of your troubleshooting, you changed the number of allowable DHCP addresses to 50. Making this change probably helped. It is never a good idea to let the range of DHCP overlap with static IP assignment. Many routers do not handle this situation well (it doesn't matter whether or not all the DHCP address are assigned.)

 

[Glorious1]

OK, so even though I never had more than 10 DHCP devices, that situation may have been screwing things up. Good to know. I'm not sure how I let that happen, since I knew they shouldn't overlap. Anyway, maybe that settles things for now. Thanks!