Project

General

Profile

Feature #972

Allow adding gateways outside of interface subnet

Added by Chris Buechler about 7 years ago. Updated almost 2 years ago.

Status:
Resolved
Priority:
Normal
Category:
Gateways
Target version:
Start date:
10/25/2010
Due date:
% Done:

100%


Description

Gateways outside of the interface's IP subnet, on Ethernet links, cannot be added under normal circumstances as it's not really a valid config and FreeBSD won't add the default gateway as normal, and will not issue ARP requests for IPs outside of directly connected subnets. The work around to add such a gateway is to run:

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

Associated revisions

Revision de34f1fc
Added by Pi Ba about 2 years ago

Allow gateway outside interface subnet. Fixes #972, #1847, and was checked (on 2.2.5) with that provider to work properly for the IPv4 part. In 2.3 test machine IPv6 also seems to insert the proper routes.

History

#1 Updated by Seth Mos about 7 years ago

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

#2 Updated by Iñigo Martinez about 7 years ago

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.

#3 Updated by Franck Bourdonnec over 6 years ago

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

#4 Updated by Mike Noordermeer over 5 years ago

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.

#5 Updated by Jim Pingle over 5 years ago

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

#6 Updated by Jim Pingle over 4 years ago

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

#7 Updated by Oliver K. almost 4 years ago

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

#8 Updated by Chris Buechler almost 4 years ago

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

#9 Updated by Dan F almost 4 years ago

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

#10 Updated by Dédé D almost 4 years ago

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).

#11 Updated by Jim Thompson about 2 years ago

  • Assignee set to Chris Buechler

PR #2119 claims to fix this and #1847

Please evaluate and report.

#12 Updated by Jim Thompson about 2 years ago

  • Target version changed from Future to 2.3

target set to 2.3

change it back if we don't want to add this now.

Looks like a low-drama PR though.

#13 Updated by Chris Buechler about 2 years ago

  • Category set to Gateways
  • Status changed from New to Feedback

It works, went ahead and merged it. The deletion doesn't happen correctly, added a comment to that PR, hopefully PiBa can follow up with a fix there.

Leaving for verification again once it's in a snapshot.

#14 Updated by Pi Ba about 2 years ago

  • % Done changed from 0 to 100

#15 Updated by Chris Buechler almost 2 years ago

  • Status changed from Feedback to Resolved

these are added and removed correctly now

Also available in: Atom PDF