• gRPC is not supported over the GCC interface. Therefore, Open Config and streaming telemetry are not supported over the GCC interface.

• Only the Tx and Rx packet count information are available in GCC statistics.

• The devices can be remotely managed over the GCC interface only when they are connected to the management network through GCC. Therefore, initial provisioning and bringing up of the GCC interface must be performed either through the console or management Ethernet interface.

• These headless or high availability events at the intermediate nodes may affect remote node management of subsequent nodes:

  • Reload of the route processor

  • Reload of IOS XR

  • Restart of the driver process

• IP fragmentation is not supported on GCC interface for the SCP protocol. As a workaround, you can apply any of the following configurations to limit the maximum packet size below the fragmentation limit (1454 bytes):

  • Use the tcp mss <maximum segment size> command (for example, tcp mss 1200 ) in the global configuration mode. The maximum segment limit is applied to all interfaces.

  • Use the ipv4 mtu <MTU size> command in the interface configuration mode. The MTU size is applied only to the specified interface.

• The Coherent DSP controller supports the GCC0 interface on the QXP card.

• The GCC0 speed on the QXP card is 7.7 Mbps.

The following protocols are supported over the GCC interface.

• PING

• SSH

• TELNET

• SCP

• TFTP

• FTP

• SFTP

• HTTP

• HTTPS

• OSPF

To configure the static routes over the GCC interface, use the following commands:

configure

router static address-family ipv4 unicast 0.0.0.0/0 default-gateway

exit

RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#router static address-family ipv4 unicast 0.0.0.0/0 10.105.57.1
RP/0/RP0/CPU0:ios(config)#exit

To configure OSPF routes over the GCC interface, use the following commands:

configure

router ospf process-id

router-id ip-address

area area-id

interface type R/S/I/P/L

exit

configure
router ospf 1
router-id 192.0.2.89                                                                                                  
 area 0                                                                                                        
  interface Loopback0                                                                                          
  !                                                                                                            
  interface MgmtEth0/RP0/CPU0/1                                                                                
  !                                                                                                            
  interface GCC20/0/0/0/1                                                                                      
  !                                                                                                            
  interface GCC20/0/0/0/2

configure
router ospf 1  
router-id 192.0.2.92
redistribute connected                                                                                             
 area 0                                                                                                        
  interface Loopback0                                                                                          
  !                                                                                                            
  interface GCC20/0/0/0/1                                                                                      
  !                                                                                                            
  interface GCC20/0/0/0/2

The Internal BGP (iBGP) support over GCC allows external devices to exchange BGP routes through management interfaces of NCS1004 system. The NCS 1004 device advertises local networks through BGP and manages these networks using path learnt through BGP. With the iBGP route information, the NCS 1004 devices establish iBGP sessions over GCC to exchange BGP routes.

You can configure VPN routing and forwarding (VRF) on the GCC management interfaces (port 0 and port 1) of the NCS 1004 device. The VRF enables traffic isolation between the management ports (port 0 and port 1).

The GCC2 and GCC0 interfaces are supported in NCS 1004 for 1.2 T line card.