# CARP using a gif tunnel



## nbari (Oct 30, 2021)

In older FreeBSD versions, a carp interface could be created using 


```
ifconfig carp create
```

And It seems to be working within a GIF tunnel, I found some rc scripts examples here: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=132107

In the latest stable FreeBSD 13 at the moment of writing this, I can create the GIF tunnel, but I can't add an alias or "attach" CARP to work within the tunnel, I get this error:


```
ifconfig: SIOCGVH: Operation not supported
```

My goal is to enable CARP in an environment that is blocking multicast, any ideas or possible solutions?


----------



## SirDice (Nov 1, 2021)

carp(4)

```
CARP virtual hosts can be configured on multicast-capable interfaces:
     Ethernet, layer 2 VLAN, FDDI and Token Ring.
```

gif(4) is a tunnel device, (layer 3; IP over IP)


----------



## nbari (Nov 1, 2021)

Wondering if gre(4) -- encapsulating network device, could work for CARP?


----------



## SirDice (Nov 1, 2021)

Let's prevent an XY problem. What issue are you trying to solve?


----------



## nbari (Nov 1, 2021)

I would like to know HA alternatives when multicast is not fully enabled, my goal, for now, is to share a VIP within two servers running HAProxy, currently partially working with CARP but following up https://forums.FreeBSD.org/threads/carp-setup-hetzner-vswitch.82604/post-539070


----------



## SirDice (Nov 1, 2021)

Hetzner has specific services for this.



			https://www.hetzner.com/cloud/load-balancer


----------



## nbari (Nov 1, 2021)

Well, in that case, I could also argue that Cloudflare may be a better alternative besides cheaper and easier,  but that's off-topic,  I am interested in finding how to improve an HA setup using dedicated hardware & CARP or alternatives.


----------

