Disable proxmox host ipv6 dhcp on WAN port

Cape

Member
Oct 28, 2015
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6
8
I migrated a node from ESXi to Proxmox today which among other things has a pfSense VM, and therefore a WAN port. I've set the WAN port up as a normal OVS bridge and passed it to pfsense, and everything works as expected.
However, I just noticed that the vmbr interface on the Proxmox host grabbed a ipv6 dhcp address from my ISP, and happily exposes ssh etc to world :eek:

I've manually removed it with ip a del 2001:... dev vmbr1 for now, but this was a nasty surprise! The UI doesn't seem to expose a "don't dhcp6" when creating bridges, any drawbacks to setting it in /etc/network/interfaces manually? I suppose there a risk Proxmox will remove it if I use the UI later...
Any other tips and tricks I should be aware of when having a WAN bridge on Proxmox?
 

niekbergboer

Active Member
Jun 21, 2016
120
39
28
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Switzerland
I don't know about DHCPv6, but I had such problems with SLAAC; editing /etc/sysctl.conf and enabling IPv6 forwarding (the comment there says something about SLAAC did the trick.

I use that in VMs with a single interface, where I don't want them to have a v6 address. YMMV.