OPNsense Forum

English Forums => General Discussion => Topic started by: pfry on November 25, 2025, 04:34:27 PM

Title: FIB/VRF support in OPNsense
Post by: pfry on November 25, 2025, 04:34:27 PM
There have been a few discussions of this in the fora; I didn't see any relevant github requests.

Would anyone be up for FIB/VRF support?

It could be implemented pretty simply. As with many OPNsense features, you could use VRFs/FIBs to really screw yourself up. But I think the feature would be quite usable. The beauty is that default behavior would not change in any meaningful sense, and it could be tested to a considerable extent without (GUI) implementation.

Details:

Possible kernel compile option: "options ROUTETABLES=n". Apparently the standard kernel can be configured (using "net.fibs", as below) for at least n=2. Appropriate setting? I imagine it would depend on impact, if any.

System:

Interfaces:

Firewall:

I've likely missed (quite) a few... e.g. "fib" for ping, trace.

Possible caveat: "route" may be fussy with fib > 0 - it might require an "up" interface in the fib in order to add routes. I'm not sure if this is a non-default behavior, as I haven't tested it.
Title: Re: FIB/VRF support in OPNsense
Post by: pfry on November 25, 2025, 05:43:59 PM
Forgot to mention: frr. Should support fibs; I haven't used it.
Title: Re: FIB/VRF support in OPNsense
Post by: AdSchellevis on November 26, 2025, 09:00:11 AM
Not at all easy to integrate (lots of moving parts), FRR by my knowledge doesn't support fibs either (e.g. https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=229136), only bird does as far as I know.

Best regards,

Ad
Title: Re: FIB/VRF support in OPNsense
Post by: bimbar on November 26, 2025, 12:05:38 PM
I also think that VRFs are not that useful in firewalls - in routers, yes, but firewalls are supposed to connect different routing contexts, not to separate them.
Title: Re: FIB/VRF support in OPNsense
Post by: pfry on November 26, 2025, 02:55:33 PM
Quote from: AdSchellevis on November 26, 2025, 09:00:11 AMNot at all easy to integrate (lots of moving parts)[...]

In context I wouldn't consider it particularly difficult, but it's not basic. Identifying all of the affected elements would be a pain, especially if they're not well encapsulated (as nobody does that).

Quote from: bimbar on November 26, 2025, 12:05:38 PMI also think that VRFs are not that useful in firewalls[...]

I'd disagree there. But I will grant that it's a bit of a niche feature, and not popular with the OPNsense base. Part of the reason for that is that for most scenarios rule-based forwarding would work about as well; another part is the chicken/egg problem, but that merely partially contextualizes the lack of demand. From a cost-benefit value standpoint it looks pretty dead.
Title: Re: FIB/VRF support in OPNsense
Post by: Fredouil on December 27, 2025, 11:44:41 AM
Hello, I disagree with this analysis. I've lost count of the number of discussions where professionals say that if OPNsense supported VRF, they would immediately switch to that solution. I know many professionals who are reluctantly forced to turn to Fortinet, VYOS, or others because they have VRF or VDOM. I truly believe it would be a huge mistake to think this feature isn't important; it should be a priority. I'm giving you my analysis as an expert and professional who regularly meets with other professionals at trade shows.
Title: Re: FIB/VRF support in OPNsense
Post by: pfry on December 29, 2025, 06:34:16 PM
Quote from: Fredouil on December 27, 2025, 11:44:41 AM[...]it should be a priority[...]

Heh. Whose confirmation bias is justified? (Does that matter?)

I'd implement it, as I come from a routing background. (Note that I started with firewalls at the same time.) I'm a lousy persuader; money talks, but I don't have enough for this one.
Title: Re: FIB/VRF support in OPNsense
Post by: Seimus on January 02, 2026, 03:26:46 AM
Quote from: Fredouil on December 27, 2025, 11:44:41 AMprofessionals say that if OPNsense supported VRF, they would immediately switch to that solution

I agree that having VRF on OPN would be great, VRF or Instances depending on the vendor are widely used on FWs as well. There is a use case for them, and a reason its needed.

But this where "they would immediately switch" "if <PRODUCT> had <this>" is just bollocks. This is the same as listening to a Windows user telling they will switch to Linux if Linux has this or that.

Regards,
S.