ZyXEL XGS19xx IPv6

nielsscheldeman

We had some strange behaviour through VLAN's. It appeared that there was on 1 VLAN an IPv6 DNS Server on an old domain controller, and in default VLAN 1 the clients sometimes got this IPv6 DNS Server. But I also saw some IPv6 gateways.

When I surfed to those gateways I expected to get the firewall, but it was the management interface of the ZyXEL XGS1930-52HP(Which I moved to a different VLAN so cliënts wouldn't be able to access it, but seems only on IPv4…)

But at another client, we have some brand new XGS1935-52HP switches and it seems that the IPv6 stack by default is turned off. Is this a firmware change? Were there complaints about it in the past. I don't get why IPv6 is turned on in the first place on XGS1930 series, not good for security.

Zyxel_Melen

Hi @nielsscheldeman

I checked that the XGS1930 and XGS1935 are both enable IPv6 on VLAN 1 interface by default. However, the IPv6 default is only acting as a DHCP client. If you want the XGS1930/1935 as a routing gateway, we normally manually set up the IPv6 address.

Many I know what do you mean about the "IPv6 stack"?

nielsscheldeman

https://community.zyxel.com/en/discussion/comment/81116#Comment_81116

Well I've seen that clients receive the IPv6 address from the ZyXEL switch as gateway if you enter IPConfig. From another VLAN there was a DNS Server active (on Windows Server) and clients seem to receive that address. After turning off IPv6 on the switch, that was gone.

With IPv6 stack I mean it can be enabled for example on a ZyXEL FLEX Firewall, so IPv6 is routed.