pfSense

As I understood from Remko Lodder there is a large ISP in .de that also employs this with their ipv6 configuration. Odd.

Gateway test should check in both subnet interface and IP ALIAS subnet.
At this moment, only subnet interface is checked, but not subnet ip alias.

well, OVH big big french provider is also using this king of setup

A well english detailled big page explain all here

http://blog.magiksys.net/pfsense-firewall-default-gateway-different-subnet

Please implement your two lines fix asap when you detect the strange configuration !
Issue a warning if you want, but don't forbide it.

Franck

This is an rather large issue for me, since my ISP is using HSRP for redundancy on IPv6, and they provide me a link-local address as gateway... I can't enter that address into PFSense and thus can't use an IPv6 IP.

AT&T is doing this now on their network handing off DHCP with a /32 mask with certain uverse gear like the NVG510, so when we fix this, we'll need to also account for supporting this inside of dhclient-script

Apparently -cloning has been deprecated in FreeBSD, so that parameter should be removed from the above command.

# route add -net gatewayip/32 -iface em0
# route add default gatewayip

Three years and counting... How is this still not implemented / patched?

because accommodating 1 in 100,000 scenarios isn't a priority, especially when there is an easy manual work around. Patches welcome.

What would be the "correct" way to make this survive reboots, please?

Hi Dan,

I felt in the same trouble, and I the idea I have found to survive reboot is using the ShellCmd package : https://doc.pfsense.org/index.php/Executing_commands_at_boot_time

I added the workaround lines in comment #6, and it works (OVH Hyper-V 2008 guest VM).