DHCP address keeps changing

Reception, channel detection, network issues, CableCARD setup, etc.
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mohoelx1
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Joined: Fri Sep 03, 2021 9:44 am

DHCP address keeps changing

Post by mohoelx1 »

Working with a Flex Duo.

Apart from the oddity of the timezone being on UTC and not reflecting the local network time, I'm wondering why it keeps dropping the link and changing IP's...? Below is a snippet of the log. I get that it should not matter much, but my set-up is that I have the Flex on a Wireless Extender device (no LAN available where my antenna comes in) which feeds into an Emby server. What I have observed a few times is that when the Flex changes IP's, I have to go into Emby and 'touch' the configuration so it can be found again. Any reason for (or way to reduce/eliminate) the drops and IP changes?

20210902-22:14:15 System: myhdhomerun_sync: webclient error (dns failed)
20210902-22:14:16 System: network link down
20210902-22:14:16 System: ip address expired
20210902-22:14:18 System: network link 100f
20210902-22:14:19 System: network link down
20210902-22:14:24 System: network link 100f
20210902-22:14:25 System: ip address obtained: 192.168.1.2 / 255.255.255.0
20210902-22:14:40 System: myhdhomerun_sync: webclient error (dns failed)
20210902-22:18:56 System: network link down
20210902-22:18:56 System: ip address expired
20210902-22:18:58 System: network link 100f
20210902-22:19:39 System: ip address obtained: 192.168.0.150 / 255.255.255.0
20210902-22:19:52 System: network link down
20210902-22:19:52 System: ip address expired
20210902-22:19:54 System: network link 100f
20210902-22:19:55 System: ip address obtained: 192.168.0.150 / 255.255.255.0
20210902-22:19:56 System: network link down
20210902-22:19:56 System: ip address expired
20210902-22:19:58 System: network link 100f
20210902-22:20:00 System: network link down
20210902-22:20:01 System: network link 100f
20210902-22:20:03 System: ip address obtained: 192.168.1.2 / 255.255.255.0
20210902-22:20:23 System: network link down
20210902-22:20:23 System: ip address expired
20210902-22:20:25 System: network link 100f
20210902-22:20:26 System: ip address obtained: 192.168.1.2 / 255.255.255.0
20210903-14:36:51 Tuner: tuner0 tuning 23.2 ATV (8vsb:557MHz-2)
20210903-14:36:51 Tuner: tuner0 streaming http to 192.168.1.28:63472

signcarver
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Re: DHCP address keeps changing

Post by signcarver »

Usually I would say such is most likely the cable or port on the switch you connect it to but could be the device's interface as well but haven't seen that as often.

However with the range of ip addresses that come up it seems you may have a strange (elaborate?) network configuration and need to ask what is your network configuration/layout is like as it is getting an ip address from 2 different networks (and the dns error could be from one of those not working, particularly if such is prevented from reaching the internet).

nickk
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Re: DHCP address keeps changing

Post by nickk »

Two things are happening...

Link going up/down - that could suggest a problem with the Ethernet path, or could be that the other end is switching to 10Mbps when idle to save power. Common with computer interfaces but switches shouldn't do that.

IP address changing - the HDHomeRun will request the same IP address if renewing an existing lease. With the Ethernet going down it releases the existing lease so may not be requesting a preferred IP. I will check on our side.

Nick

sdust
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Re: DHCP address keeps changing

Post by sdust »

These entries in the log are quite old and probably from when the device was being moved around between different networks.

mohoelx1
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Re: DHCP address keeps changing

Post by mohoelx1 »

Interesting - I hadn't picked up on the 192.168.0.x address.

I don't think I'm all that 'exotic'. I have (from the Internet down to the Flex);
- TMobile Home Internet 'modem', not using built-in WiFi but it would provide 192.168.12.x
- Wired connection to Netgear r7200 Router - configured using 192.168.1.x
- WiFi connection to Tenda AC1750 in "Wireless Repeating" mode connected to the WiFi on the Netgear, so not performing it's own DHCP (relies on the Netgear)
- Flex of course is wired into the Tenda.

So, not entirely sure where the 192.168.0.x address is coming from.... I'll try to hunt down anything offering IP's in that range, but the only routers I have in my network are offering 192.168.1.x and 192.168.12.x. The one thing I see is that during a reboot of the Tenda, it does start DHCP and then stops it at the end of the startup. I'll have to try to see if this is where the 192.168.0.x is coming to play, which would explain why the link drops as well. Hmmmm....

One weird thing is that my Tenda and the Flex show up to the Netgear as two different connected devices with their own IP's, but the same MAC - that of the Tenda. So while I've tried to do a DHCP Address Reservation, it doesn't seem to work out quite right since it is 'locking' on the MAC.

As for the log entries being 'old', those are from last night into this morning.

Thanks for the thoughts and direction. Will report back after I can test.

signcarver
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Re: DHCP address keeps changing

Post by signcarver »

Typically for such a setup you would want your tenda in bridge mode not repeating mode for such use case. I would also make sure than any DVR is wired to the tenda since that is where the tuner is connected.

mohoelx1
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Re: DHCP address keeps changing

Post by mohoelx1 »

When you say Bridge mode, do you mean AP mode? I have options of Wireless Access Point (AP) but that requires a cable connection to the router, or Wireless Repeater mode in the "Client+AP" mode, not WISP ...
WISP: After the repeating is completed, then IP address of the device that connected to Tenda is assigned by Tenda;
Client+AP: After the repeating is completed, the IP address of the device connected to Tenda is assigned by the upper router.

I cannot use the AP mode since I don't have the ability to get an ethernet cable to the location. Shoot, if I could do that, I'd just wire the Flex directly to my router!

And on a side-note, before I got a chance to try to look into any trouble-shooting, I had another IP change event. Although this time it did not 'step out' to any 192.168.0.x but rather just went to a new 192.168.1.x address. Only event in the Tenda log was that it performed a time sync at about that same time (Tenda on local time, event was 2021-09-03 17:21:23 system Sync time success)

Flex log around that time, assuming GMT vs Central US time, although the 'IP expired" is like a minute before the time sync;
20210903-16:26:27 Tuner: tuner1 http stream ended (remote closed)
20210903-17:09:35 Tuner: tuner0 http stream ended (remote closed)
20210903-22:20:23 System: ip address expired
20210903-22:20:24 System: ip address obtained: 192.168.1.36 / 255.255.255.0
20210903-23:13:30 Tuner: tuner0 tuning 23.1 CBS (8vsb:557MHz-1)
20210903-23:13:30 Tuner: tuner0 streaming http to 192.168.1.33:56777
20210903-23:15:28 Tuner: tuner0 http stream ended (remote closed)

Frustrating, but the bad part is I have to manually edit the IP in Emby server to fix (or delete and let it discover again). Of course DHCP address reservation doesn't work out since both devices are on the MAC of the Tenda. I may try WISP mode and see if that makes a difference....

mohoelx1
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Joined: Fri Sep 03, 2021 9:44 am

Re: DHCP address keeps changing

Post by mohoelx1 »

Well, WISP didn't work, but I did confirm that the 192.168.0.150 address is coming from the Tenda ... that is what was provided under WISP mode. However, being on a different network, the Flex was not able to be found by Emby or My.HDHomeRun.com, so back to Wireless Repeater mode. At least it works until the IP changes.... More digging to come.

Wondering about a set of powerline adapters instead of the Tenda device.

signcarver
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Re: DHCP address keeps changing

Post by signcarver »

what exact model... the two I checked did state they had bridge mode and I know others have complained about their "universal repeater" mode not bridging properly. The dhcp reservation should point to the mac address of the hdhr. Something you stated made me wonder if you cloned the address of the HDHR. I would factory reset the tenda and see if there are any firmware updates... after that and it still doesn't work, ditch it (I'd prefer moca over a powerline adapter if possible) and get a wireless bridge (most routers have such bridge mode) bridge mode will essentially turn the wifi connection between the two routers into a "wire" it won't repeat the signals and allow devices to connect by wifi to it (some units with multiple radios may do both but typically segregate the networks and only use the wifi connection as a gateway back to your other router).

I would also strongly recommend that whatever you choose, to put any server (i.e. dvr) on your current tenda side as you really want a wired connection between the tuner and the server but can use wifi for clients.

JDazell
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Re: DHCP address keeps changing

Post by JDazell »

mohoelx1,
Just to clarify your NETWORK connections, you stated;
- TMobile Home Internet 'modem', not using built-in WiFi
- Wired connection to Netgear r7200 Router
- WiFi connection to Tenda AC1750 in "Wireless Repeating" mode connected to the WiFi on the Netgear

So ... You have two dual band Wi-Fi Routers; a Netgear R7200(AC2100) and a Tenda W1801R(AC1750).
The Netgear is functioning as the primary Wi-Fi AP(access Point) and Router running DHCP(assigning IPs).
You have configured the Tenda as a Wireless Extender using "Universal Repeater" from the Netgear AP.
Both the Flex and the Emby are connected via wired Ethernet to the Tenda.

It seems that you have added too much complexity here. I am assuming that you can not run a wired Ethernet from the Netgear to the location where your Flex and Emby are located.

I would suggest that you get a high speed "Powerline Ethernet Adapter", such as TP-Link AV1000 or Comtrend G.hn 1200. Combining that with an inexpensive 5port Gigabit Ethernet switch such as TP-Link TL-SG105 at the other end of the Powerline and completely remove the Tenda Router from your configuration. Both the Powerline device and switch can be purchased for as little as $66 USD.
The Powerline adapter will extend one of the Ethernet ports on the Netgear to the 5Port switch, where your Flex and Emby are connected.
This will eliminate the dual MAC masking that you are currently encountering, allowing you to set IP address reservations (if you want).

If however you are also concerned with Wi-Fi signal availability in that area also then I would highly suggest that you invest in a Mesh Wi-Fi to replace all of your existing routers.
TP-Link also offers a wide range of highly aclaimed Mesh Wi-FI routers, a couple also include Powerline as a backhaul between Mesh Primary and satellite nodes.

mohoelx1
Posts: 5
Joined: Fri Sep 03, 2021 9:44 am

Re: DHCP address keeps changing

Post by mohoelx1 »

Thanks all -

A couple clarifications - the Tenda is an model AC18. And according to their doc, the only reference to 'bridge' is using the Universal "Wireless Repeating" in Client+AP mode. The documentation states upon successful configuration, "If the "Bridged successfully in Universal Repeater mode." message appears, you can access the internet through the new router." and that is where I'm at.

Unfortunately, I am not doing any sort of cloning, so the fact that the upstream Netgear is only seeing the MAC of the Tenda, and applying that to both the Tenda and the Flex, is inexplicable.

Also unfortunately, with the Tenda going through some internal gyrations whenever it restarts and/or validates the clock (causing the 192.168.0.x IP hiccup, and then a new IP being assigned by Netgear once Tenda settles back into it's "bridged" mode), and with Emby's stubbornness to hold onto the last discovered IP, this solution is not going to work for me.

The Emby server is not in the same physical location as the Flex. That is why the Tenda is even in the picture. I can't get an ethernet cable to where I *want* to have the Flex, so I'm likely going to have to move the Flex and just eliminate the Tenda.

I might go ahead and try a set of Powerline adapters, or perhaps MOCA, but doesn't MOCA need a physical cable? I don't have one of those available either, and if I were inclined to try running a cable, it would be ethernet, not coax....

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