I have 2 vnets (same subscription), one in AU (10.2.0.0/18) and one in UK (10.2.64.0/18). The vnets are connected together and virtual PCs connected to each vnet can ping each other.
My AU vnet is also connected to my on-premises router via an ExpressRoute circuit and I can ping a virtual PC in my AU vnet from my on-premises network, and the routing table of my on-premises router connected to ExpressRoute shows a route to my AU vnet via ExpressRoute.
However, my on-premises router isn't learning the route to the UK vnet at all. I'm expecting it to learn the route to the UK vnet via the AU vnet. And the UK vnet doesnt appear to be learning any routes avertised by my on-premises router.
Now the interesting part is that if I create a static route on my on-premises router to the UK vnet via my ExpressRoute circuit and try to ping or traceroute to the UK vnet the router on the Azure-end of the ExpressRoute circuit just sends 'Unreachable' replies to the pings or traceroutes. So it seems as tho the ExpressRoute circuit maintains a different routing table to the connected vnet and routes arent distributed between the routing tables.
Anyone know how to have the routes advertised by the UK vnet advertised to my on-premises router, and the routes from my on-premises router advertised to my UK vnet?