Hello, You must be so careful using this interface, have a look on the router QA:
https://community.cisco.com/t5/routing/configure-management-port-isr-4331/td-p/4182209
Q. What is the purpose of the GigabitEthernet0 on the Cisco 4000 Series?
A. The GigabitEthernet0 is the dedicated management port on the Cisco 4000 Series.
This interface connects directly to the control-plane CPU and is ideal for managing the router through Telnet,
Secure Shell (SSH) Protocol, Simple Network Management Protocol (SNMP), and other management protocols.
It is also ideal for downloading software images, uploading logs, and connecting to other management devices such as RADIUS,
Network Time Protocol (NTP), Domain Name System (DNS), Dynamic Host Configuration Protocol (DHCP), and TACACS servers.
This interface should never be used for forwarding normal data traffic through the system because every packet goes directly to the control-plane CPU,
bypassing the platform data plane. Because of this sensitivity, G0 is in a dedicated Mgmt-Intf Virtual Route Forwarding (VRF) port by default.
This setup prevents accidental routing mistakes that could cause data traffic to be routed to the management network.
INMHO is not a good to place ISP/LAN iBGP traffic on that interface, which will reach directly into control plane CPU. I'm fairly new on that but maybe this traffic will avoid data and forwarding plane before to hit the CPU, this not sounds nice for me in terms of a WAN link.
