Example converged Metasys BACnet/IP network - Metasys - LIT-12012458 - Field Device - 13.0

Metasys IP Networks for BACnet/IP Controllers Technical Bulletin

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Figure 1 illustrates a Converged Metasys BACnet/IP network. As in the earlier example, the IT department has allocated VLANs 10 through 12 and the following three /24 subnetworks for the Metasys BACnet/IP network:
  • VLAN 10:
  • VLAN 11:
  • VLAN 12:
Figure 1. Converged Metasys BACnet/IP network - example

Table 1 details the recommended IP address assignments for the devices in each of the VLANs. Note that the IP address assignments for the IP-based Metasys devices are patterned like those in the Isolated Metasys architecture example. The main difference is that for the Converged Metasys network architecture the SVIs would reside in the IT network and would be determined by IT.

Table 1. Recommended IP address assignments - converged network example



IP controllers

Network engine


Determined by IT -


Determined by IT -


Determined by IT -

IT needs to configure the SVIs in Table 1 on the distribution-layer switches that the BAS switches will use as their default gateway. If the IP addresses for the IP controllers are to be dynamically allocated, they could be allocated either by a DHCP server in the IT network since the subnetworks are allocated from the IT network's address space, or they could be allocated by DHCP servers configured on the BAS switches.

Since the devices are physically connecting to the BAS switches, the switch ports to connected devices need to be configured as access ports for the appropriate VLAN (10, 11, or 12). Additionally, since the BAS switch on the left of Figure 1 is hosting both VLANs 10 and 11, the connection between the BAS switch and the IT network would need to be configured as a trunk over which both VLAN 10 and VLAN 11 traffic is allowed. Since the BAS switch on the right is hosting only VLAN 12, the connection between the BAS switch and the IT network would be configured as a trunk over which only VLAN 12 traffic is allowed. Note that the trunks must be configured on both the BAS switch and the IT switch to which the trunk connects. As in the case of the Integrated Metasys BACnet/IP Network, appropriate routes must be configured on the IT equipment to ensure network traffic can reach these BAS networks. (For example, traffic from the Metasys server or traffic from other network engine s or BBMDs.)

The Metasys server can connect to the IT network using a general IT network access port. The IP address of the Metasys server can be assigned either a static IP address or a name (a name requires use of the IT department's DNS name server).

If a remotely located Metasys device is to be connected to the network, it can be connected to any general purpose VLAN in the IT network and assigned an IP address from the subnetwork hosted by that VLAN. However, the remotely located device must be deployed with a BBMD in the same VLAN so that the remotely located device can be discovered by one of the network engine s in VLAN 10, 11, or 12. The BBMD must have a static IP assigned from the subnetwork hosted by the VLAN and the BBMD must be configured in the BBMD table in the Metasys server . The BBMD may be one of the IP controllers in the VLAN.