Configuration Guide for Cisco NCS 1014, IOS XR Releases 26.x.x

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Configuration Guide for Cisco NCS 1014, IOS XR Releases 26.x.x

Remote node management using GCC

Updated: September 23, 2026

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This concept explains remote node management methods that use the General Communication Channel (GCC) to enable centralized control and monitoring of network elements in distributed topologies.

Remote node management using GCC is a network management method that

leverages the General Communication Channel (GCC) embedded in optical transport networks,
delivers reliable, out-of-band communication between centralized controllers and remote network nodes, and
enables real-time monitoring, configuration, and maintenance activities without requiring direct physical access to each node.

Figure 1. Remote node management in linear topology

The remote nodes can be dynamically discovered over the GCC interface using OSPF. The connectivity to the management network can be achieved using OSPF and static routes.

Supported protocols

These protocols are supported over the GCC interface:

PING
SSH
TELNET
SCP
TFTP
FTP
SFTP
HTTP
HTTPS
OSPF
SNMP
NETCONF

Note

The default VTY configuration, vty-pool default 0 99 line-template default, supports a maximum of 99 SSH sessions. To support up to 150 SSH sessions, configure a non-default VTY pool. For example: vty-pool ssh 200 299 line-template ssh.

Configure the GCC0 interface on a QXP card

Use this task to enable and configure the GCC0 interface on a Coherent DSP controller in a QXP card. Assign an IPv4 address to the interface to facilitate configuration.

The GCC0 interface operates at a data rate of 7.7 Mbps on the QXP card.

Table 1. Feature History
Feature Name	Release Information	Feature Description
GCC0 interface support on NCS1K4-QXP-K9 card	Cisco IOS XR Release 26.1.1	General Communication Channel (GCC0) interface is supported in 400G TXP and MXP modes (only in TRUNK mode OR) for the DP04QSDD-HK9 pluggable on the NCS1K4-QXP-K9 card. GCC0 interface enables you to remotely manage, monitor, and operate the chassis and line cards, especially in environments without direct Data Communication Network (DCN) access.

Note

Open Config is not supported.

Follow these steps to configure the GCC0 interface on a QXP card.

Procedure

Enter configuration mode for the Coherent DSP controller and enable the GCC0 interface.

Example:


RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#controller coherentDSP 0/0/0/0
RP/0/RP0/CPU0:ios(config-CoDSP)#gcc0
RP/0/RP0/CPU0:ios(config-CoDSP)#commit

Enter the ipv4 address ipv4-address net-mask command to assign the IPv4 address and subnet mask to the GCC0 interface.

Example:


RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#interface gcc0 0/0/0/0
RP/0/RP0/CPU0:ios(config-CoDSP)#ipv4 address 192.0.2.1 255.255.255.0
RP/0/RP0/CPU0:ios(config-CoDSP)#commit

Enter the interface Loopback R/S/I/P ipv4 address ipv4-address command to configure the interface loopback.

Example:


RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#interface Loopback0
RP/0/RP0/CPU0:ios(config-if)#ipv4 address 20.1.1.1 255.255.255.255

Enter the ipv4 unnumbered loopback 0 command to configure the GCC0 interface using the loopback IP address.

Example:


RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#interface GCC0 0/1/0/0
RP/0/RP0/CPU0:ios(config-if)#ipv4 unnumbered loopback 0
RP/0/RP0/CPU0:ios(config-if)#exit
RP/0/RP0/CPU0:ios(config)#exit

The GCC0 interface is enabled with the specified IPv4 address and configured on the Coherent DSP controller of the QXP card.

Verify the GCC0 interface status and IPv4 configuration

Use this task to confirm the operational status and assigned IPv4 address of GCC0 interfaces.

Procedure

Run the show ipv4 interface brief command to display a summary of IPv4 interfaces.

Example:


RP/0/RP0/CPU0:ios#show ipv4 interface brief
Tue Sep 16 00:40:52.056 UTC
Interface                 IP-Address      Status          Protocol        Vrf-Name
GCC00/0/0/0               198.51.100.51     Up              Up              default
MgmtEth0/RP0/CPU0/0       192.0.2.32    Up              Up              default
MgmtEth0/RP0/CPU0/1       unassigned      Shutdown        Down            default
MgmtEth0/RP0/CPU0/2       unassigned      Shutdown        Down            default

The output displays the IPv4 address, status, and protocol for GCC0 interfaces, confirming their configuration.

Configure the MTU to prevent IP fragmentation on GCC0 for SCP

Use this task to prevent IP fragmentation on GCC0 interfaces during SCP protocol operations by limiting the maximum transmission unit (MTU).

IP fragmentation is not supported on GCC0 interfaces for the SCP protocol. To avoid fragmentation, configure the interface to restrict the maximum packet size to less than 1454 bytes, which is the fragmentation limit.

Procedure

Enable the GCC0 interface and enter the ipv4 mtu size command to set the IPv4 MTU size for the GCC0 interface.

The MTU size must be 1200 bytes.

Example:


RP/0/RP0/CPU0:ios#configure
RP/0/RP0/CPU0:ios(config)#interface gcc0 0/0/0/0
RP/0/RP0/CPU0:ios(config-if)#ipv4 mtu 1200
RP/0/RP0/CPU0:ios(config-if)#commit

The IPv4 MTU is now configured on the GCC0 interface. This setting limits the maximum packet size and prevents SCP-related fragmentation.

Configure the GCC0 interface on a 2.4T card

Use this task to enable and configure the GCC0 interface on a Coherent DSP controller on a 2.4T card. Assign an IPv4 address to the interface to facilitate configuration.

Table 2. Feature History
Feature Name	Release Information	Feature Description
GCC0 interface support on NCS1K14-2.4T-K9 card	Cisco IOS XR Release 26.3.1	General Communication Channel (GCC0) interface is supported on the Coherent DSP controller in the NCS1K14-2.4T-K9, NCS1K14-2.4T-X-K9, and NCS1K14-2.4T-A-K9 with CIM8 pluggables: CIM8-LE-K9, CIM8-CE-K9, and CIM8-C-K9. GCC0 interface enables you to remotely manage, monitor, and operate the chassis and line cards, especially in environments without direct Data Communication Network (DCN) access.

Note

Open Config is not supported.

Follow these steps to configure the GCC0 interface on a 2.4T card.

Procedure

Enter configuration mode for the Coherent DSP controller and enable the GCC0 interface.

Example:


 RP/0/RP0/CPU0:ios#configure
 RP/0/RP0/CPU0:ios(config)#controller CoherentDSP0/2/0/0
 RP/0/RP0/CPU0:ios(config-ctrlr-CoherentDSP)#gcc0
 RP/0/RP0/CPU0:ios(config-ctrlr-CoherentDSP)#fec EnhancedSD15
 RP/0/RP0/CPU0:ios(config-ctrlr-CoherentDSP)#commit

Enter the ipv4 address ipv4-address net-mask command to assign the IPv4 address and subnet mask to the GCC0 interface.

Example:


 RP/0/RP0/CPU0:ios#configure
 RP/0/RP0/CPU0:ios(config)#interface GCC00/2/0/0
 RP/0/RP0/CPU0:ios(config-if)#ipv4 address 10.10.10.1 255.255.255.252
 RP/0/RP0/CPU0:ios(config-if)#commit

Enter the ipv4 mtu command to configure MTU on the GCC0 interface.

Example:


 RP/0/RP0/CPU0:ios#configure
 RP/0/RP0/CPU0:ios(config)#interface GCC00/2/0/0
 RP/0/RP0/CPU0:ios(config-if)#ipv4 mtu 1200
 RP/0/RP0/CPU0:ios(config-if)#commit

Enter the router ospf gcc0 command to configure OSPF.

Example:


 RP/0/RP0/CPU0:ios#configure
 RP/0/RP0/CPU0:ios(config)#router ospf gcc0
 RP/0/RP0/CPU0:ios(config-ospf)#router-id 10.127.60.239
 RP/0/RP0/CPU0:ios(config-ospf)#area 1
 RP/0/RP0/CPU0:ios(config-ospf-ar)#interface MgmtEth0/RP0/CPU0/0
 RP/0/RP0/CPU0:ios(config-ospf-ar-if)#passive enable
 RP/0/RP0/CPU0:ios(config-ospf-ar-if)#interface GCC00/2/0/0
 RP/0/RP0/CPU0:ios(config-ospf-ar-if)#commit

Note

For GNE nodes, the source hint includes both the MGMT and GCC0 interfaces. For RNE nodes, the source hint includes only the GCC0 interface and excludes the MGMT port because the MGMT port is down.

Enter the linux networking source-hint command to configure Linux-networking source-hint.

Example:


 RP/0/RP0/CPU0:ios#configure
 RP/0/RP0/CPU0:ios(config)#linux networking
 RP/0/RP0/CPU0:ios(config-lnx-networking)#vrf default
 RP/0/RP0/CPU0:ios(config-lnx-networking-vrf)#address-family ipv4
 RP/0/RP0/CPU0:ios(config-lnx-networking-vrf-af)#default-route software-forwarding
 RP/0/RP0/CPU0:ios(config-lnx-networking-vrf-af)#source-hint MgmtEth0/RP0/CPU0/0
 RP/0/RP0/CPU0:ios(config-lnx-networking-vrf-af)#commit

Enter the show ospf neighbor command to verify adjacencies and routes.

Example:


 RP/0/RP0/CPU0:ios#show ospf neighbor
 Neighbors for OSPF gcc0
 Neighbor ID     Pri   State     Dead Time   Address      Interface
 10.105.57.64    1     FULL/ -   00:00:30    10.10.10.2   GCC00/2/0/0
 
 RP/0/RP0/CPU0:ios#show route ospf | i 10.105.57.0|10.106.201.0
 O    10.105.57.0/24 [110/2] via 10.10.10.2, GCC00/2/0/0
 O    10.106.201.0/24 [110/3] via 10.10.10.2, GCC00/2/0/0
 
 RP/0/RP0/CPU0:ios#ping 10.10.10.2
 Success rate is 100 percent (5/5)

The GCC0 interface is configured on the Coherent DSP controller of the 2.4T card.

Verify the GCC0 interface

Use this task to confirm the operational status of configured GCC0 interface.

Procedure

Run the show interfaces gcc0 command to display the details of configured GCCO interface.

Example:


RP/0/RP0/CPU0:ios#show interfaces gcc0 0/3/0/7
GCC00/3/0/7 is up, line protocol is up 
  Interface state transitions: 4
  Hardware is GCC0
  Internet address is 10.10.10.2/30
  MTU 1504 bytes, BW 13702 Kbit (Max: 13702 Kbit)
     reliability 255/255, txload 0/255, rxload 0/255
  Encapsulation PPP,  loopback not set, keepalive set (10 sec)
  Last link flapped 04:51:21
  LCP Open
  Open: IPCP
  Last input 00:00:00, output 00:00:00
  Last clearing of "show interface" counters never
  5 minute input rate 0 bits/sec, 1 packets/sec
  5 minute output rate 0 bits/sec, 1 packets/sec
     17579 packets input, Unknown bytes, Unknown total input drops
     Unknown drops for unrecognized upper-level protocol
     Received 0 broadcast packets, 0 multicast packets
     17711 packets output, Unknown bytes, Unknown total output drops
     Output 0 broadcast packets, 0 multicast packets

The output displays the IP address, status, and MTU for GCC0 interface, confirming the configuration.

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