> - Downloads
> - Overview of External Interfaces on a C Series Controller
> - Related Topics
> - Configuring Ethernet Redundancy (SRC CLI)
> - Configuring Gigabit Ethernet Interfaces for IPv4 (SRC CLI)
> - Configuring Gigabit Ethernet Interfaces for IPv6 (SRC CLI)
> - Configuring Tunnel Interfaces (SRC CLI)

> ## Overview of External Interfaces on a C Series Controller

> The C Series Controller provides the following interfaces:

> - Serial port—9600 baud

>   The serial port is enabled by default. You can use the serial port to connect to a console terminal and perform initial configuration as well as configuration updates.

> - Two external Gigabit Ethernet interfaces—eth0 and eth1

>   The eth0 interface is designed to provide access from a network that is behind a firewall. This interface accepts connections from protocols supported by the SRC software. When you configure an SRC component, the specified port is opened on this interface.

>   The eth1 interface is designed to provide access for applications on an external network, such as the Internet. You can configure a limited number of ports on this interface. By default, no inbound ports are open.

> - Optional two additional Gigabit Ethernet interfaces—eth2 and eth3

>   These interfaces require an additional input/output module. You can obtain a module to support either RJ-45 or optical connections.

> - Two USB interfaces

> ## Tunnel Interfaces

> A tunnel allows direct connection between a remote location and an application running on the C Series Controller; a tunnel lets you use the redirect server in deployments where a router running JUNOSe Software does not have a direct connection to the C Series Controller.

> The C Series Controller supports the following types of tunnel interfaces:

> - GRE—Generic routing encapsulation. Encapsulates traffic that can use various network protocols within IP. For C Series Controllers, the tunnel interface encapsulates IP packets.
> - IP-over-IP—Encapsulates IP packets within IP packets.
> - SIT—Encapsulates IPv6 traffic in an IPv4 tunnel. This type of tunnel allows compatibility of IPv6 traffic within an IPv4 network.

> The other endpoint for the tunnel on a device must be configured for the tunnel to be operational.

> The local address of a tunnel connection is an IP address that is configured for a unit (logical interface). Before you configure a tunnel interface, configure the interface on the C Series Controller.

> See Configuring Gigabit Ethernet Interfaces for IPv4 (SRC CLI) .

> ## Ethernet Redundancy

> Group interfaces let you aggregate network interfaces into a single logical interface to support Ethernet redundancy. The group interfaces provide either hot standby or load-balancing services.

> When you configure group interfaces, be aware of the following restrictions:

> - The group interface name must not be one of the Ethernet interface names (that is, eth0, eth1, eth2, eth3).
> - If an Ethernet interface is listed inside a group interface, it must not be configured as an interface by itself at the [edit interfaces name unit] hierarchy level.
> - Group interface and tunnel interface configurations are mutually exclusive. You cannot configure both types at the same time.

> You can group interfaces in the following modes:

> - Round-robin policy (balance-rr)—Transmit packets in sequential order from the first available device through the last.
> - Active-backup policy (active-backup)—Create only one device that is active. A different device becomes active if, and only if, the active device fails.
> - XOR policy (balance-xor)—Transmit based on the selected transmit hash policy.
> - Broadcast policy (broadcast)—Transmit everything on all device interfaces.
> - IEEE 802.3ad Dynamic link aggregation (802.3ad)—Create aggregation groups that share the same speed and duplex settings.
> - Adaptive transmit load balancing (balance-tlb)—Create channel bonding that does not require any special switch support.
> - Adaptive load balancing (balance-alb)—Includes adaptive transmit load balancing (balance-tlb) plus receive load balancing (rlb) for IPv4 traffic, and does not require any special switch support.

> You can monitor link integrity with the MII monitor.

> The MII monitor monitors only the carrier state of the local network interface. The MII monitor does not provide a high level of detection for end-to-end connectivity failures.

> #### Published: 2009-09-25

> Copyright © 2009, Juniper Networks, Inc. All rights reserved. Trademark Notice.