We're in the process of (hopefully) dumping a number of L2 WAN connections in favor of higher speed Internet connections and doing GRE over them back to our Data Center. Ideally, we're looking to ditch Cisco along the way and convert these to Mikrotik. That said, we're stumped as it seems our configuration should work (and it appears it's close) but doesn't.

To explain how we're attempting to configure this, we've got an interface tied to an ISP with a static IP on ether1 (/30). For that, we have a default route in the main routing table routing all traffic to their gateway.

We separately configured another VRF (Tunnel105) that's used for all of our customer routing so we can maintain existing IP's/routing and also inject OSPF routes into an isolated routing table. All of this seems to work fine. The customer has access to their IP's, can ping out to the Internet, routing tables populate the way we expect, etc. The problem is, the moment they start passing 4-5mbps (which is the absolute most they can pass), pings to the public IP of the Mikrotik (where ISP connects) spikes from 20-30ms to 500-800ms, packet loss is nearly 50-60% and we can hardly access the Mikrotik remotely. This is a 500x50mbps connection and we can attain those speeds (roughly) doing a speedtest through the Mikrotik when configured for NAT.

This seemed like the cleanest configuration to isolate routing required for an internet connect to work vs a routing table that's used to do our routing for customer network(s).

Any clues as to what we're missing? The configuration to one of our remote nodes is listed below. The router their connecting to on the other end of this is also a Mikrotik CCR1009. While it "feels" like a heavily loaded CPU, that remains at 0% on both units.

Thank you very much for the help!

/interface ethernet
set [ find default-name=ether1 ] name="ether1 - ISP” speed=100Mbps
set [ find default-name=ether2 ] speed=100Mbps
set [ find default-name=ether3 ] name="ether3 - Customer" speed=100Mbps
set [ find default-name=ether4 ] speed=100Mbps
set [ find default-name=ether5 ] speed=100Mbps
set [ find default-name=ether6 ] speed=100Mbps
set [ find default-name=ether7 ] speed=100Mbps
set [ find default-name=sfp-sfpplus1 ] advertise=10M-full,100M-full,1000M-full
/interface gre
add !keepalive mtu=1400 name="gre-tunnel105 - DC01” remote-address=x.x.x.x (public IP of Mikrotik in Data Center)
/interface wireless security-profiles
set [ find default=yes ] supplicant-identity=MikroTik
/routing ospf instance
set [ find default=yes ] distribute-default=if-installed-as-type-2 metric-default=5 redistribute-connected=as-type-2 redistribute-static=as-type-2 router-id=10.30.0.22 routing-table=Tunnel105
/ip address
add address=192.168.88.1/24 interface=combo1 network=192.168.88.0
add address=x.x.x.1/24 interface="ether3 - Customer" network=x.x.x.0
add address=x.x.x.1/24 interface="ether3 - Customer" network=x.x.x.0
add address=10.30.0.22/30 interface="gre-tunnel105 - DC01” network=10.30.0.20
add address=x.x.x.194/30 interface="ether1 - ISP” network=x.x.x.192 (Public IP’s from ISP)
/ip cloud
set ddns-enabled=yes ddns-update-interval=5m
/ip dhcp-client
add disabled=no interface=combo1
/ip route
add distance=1 gateway=x.x.x.193
/ip route vrf
add comment="GRE Tunnel to DC01” interfaces="gre-tunnel105 - SVDC01,ether3 - Customer" routing-mark=Tunnel105
/ip service
<removed for security>
/routing ospf network
add area=backbone network=10.30.0.20/30
/system identity
set name=RBR142
/tool sniffer
set filter-interface="ether3 - Customer"

Bueller? Bueller? Is this not a common configuration?