Frequent & repeated of IP address to new network device

Guru - Experienced User

Aug 02, 2021

GwentLarry wrote:

The router log lists [DHCP IP: (10.175.0.3)] to MAC address 28:B7:7C:14:86:18 four or five times an hour. That MAC address is the SolarEdge inverter. This doesn't happen with other devices on my home network.

So it is more a case of the router logging an incoming connection request than "resending the same LAN IP address to the inverter".

So your theory about the wifi begins to make sense. Or it could be that the inverter tries connecting to a schedule.

The router is just logging what goes on.

That 10.175.0.3 IP address is a bit puzzling. It isn't one of usual 192.168.x.x defaults, and usually happens when there is something else on the network handing out IP addresses.

There's a long discussion about SolarEdge inverters here:

Solved: Constantly dropping connectivity - NETGEAR Communities

That's why I asked what it is.

I have no idea if it adds anything useful to your search for information. But it may suggest some things to try.

GwentLarry wrote:

And I find the options for where to ask questions rather less than obvious … :-)

You are being too kind to the system, which is also responsible for the gaps in the drop-down options.

GwentLarry
Aspirant
Aug 03, 2021
Well, I guess it is a 2-way process? The SolarEdge Inverter requests an IP address and the router send it - whatever, an IP address is being provided 4 or 5 times an hour which seems unusual to me for a device which is permanently on and nominally always connected to my LAN.

However, as you say, it could be that the SolarEdge Inverter is simply connecting to upload data according to a schedule …

While 192.168.x.x are the more usual IP addresses for private LANs, 10.x.x.x IP addresses are similarly reserved for private LANs. I've set up my router to use 10.x.x.x for several reasons:

1. Initially, in order to access from home my employers intranet via a VPN. They were using 192.168.x.x and if my home router used the same sequence, it caused problems, so, on the advice of my employers' IT manager, I changed my router addressing to 10.175.x.x and never bothered to change back.

2. Almost everybody assumes private LANs use 192.168.x.x By using a different sequence, I consider it makes my home network more secure, if only marginally.

3. Why not use 10.x.x.x ?

Thanks for the link to SolarEdge Inverter connectivity.

I guess the issue here is that something is happening which is unusual and I want to understand why - everything works but there is something I don't understand :-)

Thanks
- michaelkenward
  Guru - Experienced User
  Aug 03, 2021
  GwentLarry wrote:
  
  Well, I guess it is a 2-way process? The SolarEdge Inverter requests an IP address and the router send it - whatever, an IP address is being provided 4 or 5 times an hour which seems unusual to me for a device which is permanently on and nominally always connected to my LAN.
  
  My confusion is in the "send" word. The router is sending nothing to the inverter beyond the usual network traffic. The router is simply recording that it has received, and accepted, a request for an IP connection. It "sent" that information to the logs.
  
  I asked about "sending" because it implied that the router was engaged in some sort of conversation with the inverter. That isn't terminology that people use in these circumstances, which is why I said I didn't understand what you were saying.
  
  GwentLarry wrote:
  
  While 192.168.x.x are the more usual IP addresses for private LANs, 10.x.x.x IP addresses are similarly reserved for private LANs. I've set up my router to use 10.x.x.x for several reasons:
  
  I am familiar with all of that. And your explanation makes sense.
  
  I asked about it because when someone reports an IP address in that range it can be a sign of a messy network. If their router picked that 10.x.x.x address, without any deliberate action on the part of the user, it can be a sign of another router on the network, often a modem/router that would be better put into modem only mode. Knowing that is a useful diagnostic guide when trying to troubleshoot network problems. It is just one of the things on the usual checklist.
  
  GwentLarry wrote:
  
  2. Almost everybody assumes private LANs use 192.168.x.x By using a different sequence, I consider it makes my home network more secure, if only marginally.
  
  That 10.x.x.x is also a well known internal IP network may not add much, ir anything, to your network security. It might, though, cause problems with devices that aren't used to that sort of address. But that's your call.
  - antinode
    Guru
    Aug 03, 2021
    > So it is more a case of the router logging an incoming connection
    > request than "resending the same LAN IP address to the inverter".
    
       Is that what it is? Is it a "connection request", or simply a DHCP
    lease renewal? What appears in the log when a wireless device connects?
    Just this, or more than this? Is the device disconnecting/reconnecting,
    or staying connected, and just renewing its DHCP data (pointlessly
    often)?
    
       The DHCP server in a typical Netgear router is configured with a
    fixed lease time of 86400s (1 day). A client device can request a
    renewal at any time, but a competent client device wouldn't do that
    before, say, the half-way point (so, twice per day).
    
          https://community.netgear.com/t5/x/x/m-p/1667716
    
    > That 10.175.0.3 IP address is a bit puzzling. [...]
    
       Not to everyone. The user chose it. It's simply one of the 64K
    possible "10.a.b.*" subnets.
    
    > 2. Almost everybody assumes private LANs use 192.168.x.x By using a
    > different sequence, I consider it makes my home network more secure, if
    > only marginally.
    
       If anyone gets onto your LAN, I doubt that an exotic IP address
    subnet will make the slightest difference.
    
    > 3. Why not use 10.x.x.x ?
    
       No reason. If you used "10.0.0.*", then you might not puzzle a few
    easily puzzled people. Most important: "10.0.0" is easier to type than
    "10.175.0".
    
    > [...] It might, though, cause problems with devices that aren't used
    > to that sort of address. [...]
    
       I've never seen a device which couldn't cope with "that sort of
    address". One 32-bit number is about as exotic as any other 32-bit
    number.
    
    > I asked about "sending" because it implied that the router was engaged
    > in some sort of conversation with the inverter. [...]
    
       The client device sent (broadcast) a DHCP request to the LAN. The
    router (DHCP server) received it, and sent a response to the client
    device. Anyone _I_ know might call that exchange of messages a
    "conversation".
    
       "I don't think of it that way" and "That's wrong" are two different
    concepts, between which some people have (great) difficulty
    distinguishing.

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Frequent & repeated of IP address to new network device