libvirt users - May 2016 - Connectiviity between Guest and Host

Hello everyone,
 
I have followed this guide to enable my Windows 10 guest to reach my
Arch Linux host:
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Virtualization_Host_Configuration_and_Guest_Installation_Guide/App_Macvtap.html
 
My VM now has 2 NICs:
- macvtap (VEPA)
- virtual network 'isolated'
 
I have statically assigned the IP 192.168.254.2 to my guest. The host's
IP is 192.168.254.1. The interface it is using on the host is *virbr1*.
 
I am able to ping the host from the guest and vice versa, so the network
connectivity seems to be generally working. To control my VM I'd like to
use Synergy which I have already set up and tested successfully once
with the VM as the Server, but never since. When I try to connect the
Synergy client from the host to a server running on the guest, I get the
error *"failed to connect to server: address not found for:
192.168.254.2"*.
 
This is the result of nmap:
[root@thearch ~]# nmap 192.168.254.0/30
 
Starting Nmap 7.12 ( https://nmap.org ) at 2016-05-14 17:14 CEST
Nmap scan report for 192.168.254.2
Host is up (0.0010s latency).
Not shown: 995 filtered ports
PORT      STATE SERVICE
135/tcp   open  msrpc
139/tcp   open  netbios-ssn
445/tcp   open  microsoft-ds
5357/tcp  open  wsdapi
24800/tcp open  unknown
MAC Address: 52:54:00:96:11:A9 (QEMU virtual NIC)
 
Nmap scan report for 192.168.254.1
Host is up (0.0000040s latency).
Not shown: 999 closed ports
PORT   STATE SERVICE
53/tcp open  domain
 
Nmap done: 4 IP addresses (2 hosts up) scanned in 5.16 seconds
 
I also did nmap from a non-root user:
[christopher@thearch ~]$ nmap 192.168.254.0/30
 
Starting Nmap 7.12 ( https://nmap.org ) at 2016-05-14 17:17 CEST
Nmap scan report for 192.168.254.1
Host is up (0.000073s latency).
Not shown: 999 closed ports
PORT   STATE SERVICE
53/tcp open  domain
 
Nmap done: 4 IP addresses (1 host up) scanned in 1.26 seconds
 
As you can see, the host 192.168.254.2 is only found when running
nmap with root, not with my other user. Pinging the guest still
works however.
 
I suspect this is the core of the issue, but I don't know how to solve
it. Any suggestions are appreciated.
 
Thanks,
Christopher Mühl