When dhcp client ipv6 is assigned in paloalto vm-series, the gateway is the same on both NICs.

Question

When dhcp client ipv6 is assigned in paloalto vm-series, the gateway is the same for both NICs.

The subnets are created differently, but the gateways are different.

Answer 1

Hello jmhwang

Could you please elaborate your issue in detailed:

Based on description you have observed that both NICs on your Palo Alto VM-Series firewall are receiving the same IPv6 gateway address, even though they are in different subnets.

To resolve this, assign each NIC to a separate virtual router, verify RA behavior, and configure static default routes if needed.

In Azure, use UDRs to enforce subnet-specific routing.

Enable diagnostic logging to confirm the correct gateway assignments. If the issue persists, coordinate with your ISP for further investigation

Additionally, you can verify the Dual Stack Considerations and subnets:

1. If you're using a dual-stack setup (both IPv4 and IPv6), make sure that both protocols are configured independently and are not conflicting with each other or reusing configurations.
2. Subnet Configuration: Look closely at how the subnets are laid out. Even though the configurations seem different, verify that they truly are distinct in the DHCP options being referenced.

I hope this information is helpful! If my answer helped you resolve your issue, please consider marking it as the correct answer or Upvote. This helps others in the community find solutions more easily. Thanks!