# 'linux_bridge' - linux bridge will be configured
# 'buildin' - nothing will be configured by vsperf; VM image must
# ensure traffic forwarding between its interfaces
+# 'clean' - nothing will be configured, but automatic login will
+# be performed; Useful for stepdriven testcases.
# For 2 VNFs you may use ['testpmd', 'l2fwd']
GUEST_LOOPBACK = ['testpmd']