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podgerodge's avatar
podgerodge
Tuning in
7 months ago
Solved

At wits end - DHCP issues with Virgin Media

Long story short, have a new router and rebooted it (trying to fix a separate problem) and lost internet access. It's now disconnected and wifi re-enabled on Virgin Media box (in router mode which was working fine with wifi disabled).

Now, I have access on some devices. But not on others. Example - an internet radio keeps giving "network timeout" and dhcp errors. So I went into Hub 2.0 and looked at DHCP lease time (not that I have a clue) and it was 24 hours (86400). I changed that to 2 minutes (120) and the internet radio immediately came on. Switched it back to 86400 and timeout again immediately.

 

I haven't a clue what is going on, but I suspect that DHCP issues from the Virgin Hub are probably causing the fact that my router and radios etc. are all very confused.

Any suggestions? Can a 2 minute DHCP lease cause other issues, and if I revert to 24 hours, and turn the modem off, will everything unlease itself and go back to normal. Thanks!

  • Client62's avatar
    Client62
    7 months ago

    OK I am now confused.

    In the original post the Hub 2 DHCP lease period is mentioned - hence assume Hub 2 is in Router mode.

    But in the most recent post a Asus AX52 Router is mentioned - configuration not known.

    I would expect the configuration to be Hub 2 in modem mode + Asus AX52 in router mode performing DHCP.

    What the post suggests is the Hub 2 is Router mode with DHCP enabled + Asus AX52 but how is this configured ?

    Are there two active DHCP severs on the LAN each issuing IPs on a different subnets leading to devices working or not in a hit and miss basis.

  • legacy1's avatar
    legacy1
    Alessandro Volta
    7 months ago

    put hub in modem mode get your own router with 1Gb ports

  • Client62's avatar
    Client62
    Alessandro Volta
    7 months ago

    Use whatever DHCP lease time gets the Hub 2 to work until you can request a replacement VM Hub.

  • podgerodge's avatar
    podgerodge
    Tuning in
    7 months ago

    Thanks both.

    The router is a brand new Asus AX52 and the hub was delivered last week new to replace an old one. 

    All worked fine until I started messing yesterday!

    I'll try modem mode. 

  • Client62's avatar
    Client62
    Alessandro Volta
    7 months ago

    OK I am now confused.

    In the original post the Hub 2 DHCP lease period is mentioned - hence assume Hub 2 is in Router mode.

    But in the most recent post a Asus AX52 Router is mentioned - configuration not known.

    I would expect the configuration to be Hub 2 in modem mode + Asus AX52 in router mode performing DHCP.

    What the post suggests is the Hub 2 is Router mode with DHCP enabled + Asus AX52 but how is this configured ?

    Are there two active DHCP severs on the LAN each issuing IPs on a different subnets leading to devices working or not in a hit and miss basis.

    • podgerodge's avatar
      podgerodge
      Tuning in
      7 months ago

      Router is an Asus AX52 purchased last week.

      Originally, when I set it up, the Virgin Media Hub was in Router Mode, but I disabled the 2.4 and 5ghz wifi. The Virgin Hub was accessible (and still is) on 192.168.0.1 . The setup page for the Hub (which currently has the 2 minute DHCP lease due to my change) shows "starting local address" of 192.168.0.10. I have never used Modem mode to date.

      I then initially had the AX52 in Router Mode and as far as I recall, the ip address assigned was 192.168.50.1, before changing it to AP mode (for some reason that I don't recall) and it all worked fine either way.

      I think I messed up the Asus app at some point when I was trying to figure out why a mobile phone wouldn't connect to the wifi (it turned out that it was because it was Wifi6 that the phone couldn't connect to), and at that stage the damage was done as all the problems began.

      The router is completely removed from the equation now as I try to figure things out. But the internet timeout persists, albeit I think it's only on 1 device now, the internet radio.

      Perhaps there is some double dhcp thing going on? 

      As i said to someone else, I'm the person they wrote "a little knowledge is a dangerous thing" about. 

  • podgerodge's avatar
    podgerodge
    Tuning in
    7 months ago

    Separately, in my initial setup, I was wired from my VM Hub to the WAN port of the Asus - if all I'm trying to achieve is a better wifi signal, am I better off wiring from VM Hub to a LAN port of the Asus - would that keep everything on the same network, no "double nats" or whatever, and allow me to broadcast Wifi from the Asus (having disabled wifi on the Hub)?  Apologies if I am talking nonsense!

  • podgerodge's avatar
    podgerodge
    Tuning in
    7 months ago

    @Client62

    IGNORE previous posts.  I seem to have solved things.  Including someone on an Irish bulletin board suggesting I assign the Asus MAC address to a dedicated 192.168.0.250 on the VM modem.

    As I actually had port forwarding for CCTV on my Hub, and ALSO 2 ethernet cables from the VM Hub running over my roof to provide wired access in 2 rooms, I didn't want to go into Modem Mode - as my understanding is that this would stop those LAN ports working.

    So…I assigned the Asus MAC address which I found on the back of the Asus, to 192.168.0.250. That's handy - as I can know that this is always going to be the login page for the Asus on my pc.

    I then disabled WIFI on the VM Hub, re-setup the Asus which automatically went into Router Mode, but then changed that to AP mode and bingo, all looks ok.

    I'm not sure if I'm technically in this "double nat" thing but seems grand.

    • TommyMcArdle's avatar
      TommyMcArdle
      Tuning in
      7 months ago

      Things are far from grand the way you've set that up. If you are going to use an another router (as a router!) but the hub in modem mode.

      • podgerodge's avatar
        podgerodge
        Tuning in
        7 months ago

        But I put the Asus in AP mode so it's not being used as a router?  Is that not sufficient?

    • legacy1's avatar
      legacy1
      Alessandro Volta
      7 months ago
      podgerodge wrote:

      I didn't want to go into Modem Mode - as my understanding is that this would stop those LAN ports working.

      you get them LAN ports back by your router

  • bagleyic's avatar
    bagleyic
    Joining in
    4 months ago

    Just change the 3rd digit on DHCP starting range to something else, e.g. 192.168.1.10

    This has the effect of also changing the IP address of the router to 192.168.1.1 so if you have any static addresses anywhere or router FW rules you will need to change those too.

    (and if you actually just want to change the IP address of the router this is the only way I've found, albeit limited)

    It seems to effectively reset the DHCP server and it starts issuing new leases from 192.168.1.10 ...

    Added benefit is it will be obvious if anything is getting leases from anywhere else as they will be 192.168.0.n