I didn't actually try to configure a routing protocol, but the programs run. If one can use an interface index instead of an IP address in ip_mreq.imr_interface (from netinet/in.h) on DragonFly (like on FreeBSD), it should be okay.
In my opinion, there is no point in keeping net/zebra since it's been unmaintained for almost ten years and quagga is a fork. So you may want to disable zebra from the automatic builds, since it doesn't build anyway.
Here is a simple fix that allows net/quagga to build: http://vrac.lm7.fr/dports-fixes/net/quagga/Makefile.DragonFly
I didn't actually try to configure a routing protocol, but the programs run. If one can use an interface index instead of an IP address in ip_mreq.imr_interface (from netinet/in.h) on DragonFly (like on FreeBSD), it should be okay.
In my opinion, there is no point in keeping net/zebra since it's been unmaintained for almost ten years and quagga is a fork. So you may want to disable zebra from the automatic builds, since it doesn't build anyway.