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Cisco ASR 1000 Series Aggregation Services Routers Software Configuration Guide
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Chapter 9 Using the Management Ethernet Interface
Gigabit Ethernet Port Numbering
Gigabit Ethernet Port Numbering
The Gigabit Ethernet Management port is always GigabitEthernet0.
In a dual RP configuration, the Management Ethernet interface on the active RP will always be Gigabit
Ethernet 0, while the Management Ethernet interface on the standby RP will not be accessible using the
Cisco IOS CLI in the same telnet session. The standby RP can be telnetted to through the console port,
however.
The port can be accessed in configuration mode like any other port on the Cisco ASR 1000 Series
Routers:
Router#
config t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#
interface gigabitethernet0
Router(config-if)#
IP Address Handling in ROMmon and the Management Ethernet
Port
On the Cisco ASR 1000 Series Routers, IP addresses can be configured in ROMmon (the
IP_ADDRESS=
and
IP_SUBNET_MASK=
commands) and through the use of the IOS command-line
interface (the
ip address
command in interface configuration mode).
Assuming the IOS process has not begun running on the Cisco ASR 1000 Series Router, the IP address
that was set in ROMmon acts as the IP address of the Management Ethernet interface. In cases where the
IOS process is running and has taken control of the Management Ethernet interface, the IP address
specified when configuring the Gigabit Ethernet 0 interface in the IOS CLI becomes the IP address of
the Management Ethernet interface. The ROMmon-defined IP address is only used as the interface
address when the IOS process is inactive.
For this reason, the IP addresses specified in ROMmon and in the IOS CLI can be identical and the
Management Ethernet interface will function properly in single RP configurations.
In dual RP configurations, however, users should never configure the IP address in the ROMmon on
either RP0 or RP1 to match each other or the IP address as defined by the IOS CLI. Configuring matching
IP addresses introduces the possibility for an active and standby Management Ethernet interface having
the same IP address with different MAC addresses, which will lead to unpredictable traffic treatment.
Gigabit Ethernet Management Interface VRF
The Gigabit Ethernet Management interface is automatically part of its own VRF. This VRF, which is
named “Mgmt-intf,” is automatically configured on the Cisco ASR 1000 Series Router and is dedicated
to the Management Ethernet interface; no other interfaces can join this VRF. Therefore, this VRF does
not participate in the MPLS VPN VRF or any other network-wide VRF.
Placing the management ethernet interface in its own VRF has the following effects on the Management
Ethernet interface:
•
Many features must be configured or used inside the VRF, so the CLI may be different for certain
Management Ethernet functions on the Cisco ASR 1000 Series Routers than on Management
Ethernet interfaces on other routers.
