In this example an HWIC-16a is installed in a 2921 ISR G2 router’s slot 0/0.  The management port is configured to a VRF called “MGMT”.  The hostnames for the connected devices are set with the “ip host” line along with the VRF, port number (port 0 = tcp port 2003) and local router’s IP address.

hostname isr2921
interface Port-channel1.10
 encapsulation dot1Q 10
 ip vrf forwarding MGMT
 ip address 10.10.10.10 255.255.255.0
!
ip host vrf MGMT router1 2003 10.10.10.10
ip host vrf MGMT router2 2004 10.10.10.10
!
line 0/0/0 0/0/15
 session-timeout 30 
 exec-timeout 30 0
 transport input telnet ssh
!

To connect, specify the VRF name as a parameter

isr2921#telnet router1 /vrf MGMT
Translating "router1"
Trying router1 (10.10.10.10, 2003)...