The method of using the Forward Networks search bar to list all devices where a subnet is learned or advertised is very useful. This NQE lists the route, egress interface, interface description and a bit more. Displaying the next hop MAC address and associated OUI vendor is useful in determining whether the next hop is a router or firewall. 
 

/**
 * @intent List IP Prefixes / Route Table entries for all Routers
 * @description List the Route Table and egress interfaces detailes.  Useful to determine where a particular route is, and what routes egress a device or interface.
 */
getNextHopDesc(deviceName, interfaceName) =
  foreach interface in deviceName.interfaces
  where interface.name == interfaceName
  select interface.description;

getNextHopMac(deviceName, interfaceName, ipNextHop) =
  foreach interface in deviceName.interfaces
  foreach subinterface in interface.subinterfaces
  let ipv4 = subinterface.ipv4
  foreach neighbor in ipv4.neighbors
  where neighbor.ip == ipNextHop
  select neighbor.linkLayerAddress;

foreach device in network.devices
foreach networkInstance in device.networkInstances
let afts = networkInstance.afts
where isPresent(afts.ipv4Unicast)
let ipv4Unicast = afts.ipv4Unicast
foreach ipEntry in ipv4Unicast.ipEntries
foreach nextHop in ipEntry.nextHops
// where nextHop.originProtocol == OriginProtocol.BGP
let intDesc = getNextHopDesc(device, nextHop.interfaceName)
let nextHopMac = getNextHopMac(device, nextHop.interfaceName, nextHop.ipAddress)
foreach uniqueMac in nextHopMac
let ouiVendor = ouiAssignee(uniqueMac)
select {
  deviceName: device.name,
  networkInstanceName: networkInstance.name,
  ipEntryPrefix: ipEntry.prefix,
  originProtocol: nextHop.originProtocol,
  nextHopInterface: nextHop.interfaceName,
  nextHopIP: nextHop.ipAddress,
  nextHopMac,
  macVendor: ouiVendor,
  intDesc
}