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Bala Sundaram's avatar
Bala Sundaram
Brass Contributor
Sep 24, 2018

Hyper-V Default switch IP address range change. Ver 1809 Build 17763.1

Can one confirm IP address range changed to 192.168.X.Y Subnet 255.255.255.240 from 172.X.X.X   Also changes the subnet randomly on every Hyper-V services startup. 192.168.X.Y . X can change from 5...
Bala Sundaram's avatar
Bala Sundaram
Brass Contributor
Dec 05, 2018

Hello cbj4074,

 

I do not know why I said something very wrong. Sorry for misleading. I checked again, It appears the unpredictable IP address on default switch issue exists in build 17763.104 too. Darn thing assigns CLASS C (172.17.239.XXX) or CLASS D (192.168.75.XXX). It is still unmanegable. May be I was clouded by the workaround I had in place. 

 

Basically I created a work around to take advantage of default switch as my two Physical NICs are teamed and fault tolerant.

 

  1. Created an Internal Switch
  2. Also have default switch that piles up on the bridged NIC (ICS)
  3. Have to VNIC's on the guest.
    1. Internal Switch based NIC is Static 192.168.5.XXX (255.255.255.0) for guest to guest communication.
    2. Default switch based NIC is Dynamic for Internet access

Regards,

Bala

 

Remon li's avatar
Remon li
Copper Contributor
Dec 06, 2018

17763.168 released , is it fixed or not ?

  • Bala Sundaram's avatar
    Bala Sundaram
    Brass Contributor
    Dec 06, 2018
    Took it down 17763.168 last night and was hoping it will be corrected. Confirming still has same issue and default switch is unmanagable exactly like ICS definition.

    Only new thing it is assigning only class D Network ip address.

    First two octet seems stabilized. 192.168.XXX.YYY. can change on every Hyper-V service start/stop
    • Remon li's avatar
      Remon li
      Copper Contributor
      Dec 06, 2018
      Bad news. I'm afraid develop team take it as new featuer instead of bug.
      • Ethan_C's avatar
        Ethan_C
        Copper Contributor
        Jul 16, 2020

        Remon li it's a bug.

         

        Use case:  VPN that conflicts with 172.17.x.x network range.  Win10 client boots; does network conflict detection; see's free address and makes the default nat adapter 172.17.109.x and ads route 172.17.109.224 255.255.255.240 On-link 172.17.109.x 5256...  Note: 5k metric.  now VPN client is connected.  on connect; route for 172.16.0.0/12 is added with a metric of 2.  the hyper-v VM is now unreachable.  We need to be able to control a "safe" network pool for the default nat network to pull from.

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