Interfaces and Hardware Component Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases

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Interfaces and Hardware Component Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases

GUEv1 static tunnel configuration over IPv4 networks

Updated: July 31, 2026

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This topic describes Generic UDP Encapsulation variant 1 (GUEv1) static tunnel configuration over IPv4 networks on the Cisco 8000 Series Router, which enables scalable and secure deployment of GUEv1 tunnels to carry IPv4 and IPv6 traffic.

A GUEv1 static tunnel is a user-specified tunnel that

  • is configured between two endpoints using static route configuration that includes a next-hop IP address,

  • enables efficient, scalable, and secure deployment of GUEv1 tunnels, and

  • carries IPv4 and IPv6 traffic over IPv4 networks.

Starting from Cisco IOS XR Release 25.4.1, you can configure GUEv1 static tunnels to carry IPv4 and IPv6 traffic over IPv4 networks.

Table 1. Feature History Table

Feature Name

Release Information

Feature Description

GUEv1 static tunnel configuration over IPv4 networks

Release 25.4.1

Introduced in this release on: Fixed Systems (8200 [ASIC: Q200]); Centralized Systems (8600 [ASIC: Q200]); Modular Systems (8800 [LC ASIC: Q200])

This feature enables highly efficient, scalable, and secure deployment of Generic UDP Encapsulation variant 1 (GUEv1) static tunnels to carry IPv4 and IPv6 traffic over IPv4 networks.

In addition, this feature enables the router to use GUEv1 as the overlay encapsulation type for network virtualization endpoint (NVE) and send encapsulated overlay traffic to IPv4, IPv6, and MPLS destinations using UDP ports.

With this feature, you can also increase the GUEv1 scale up to 12K tunnels.

This feature introduces these changes:

CLI:

  • The address-family ipv4 unicast and address-family ipv6 unicast commands are modified to include these keywords: remote-next-hop , tunnel , source-ip , dscp , and ttl .

  • A new command, nve overlay-encap guev1 udp-port destination , has been introduced.

Configuration guidelines for GUEv1 static tunnels

Apply these guidelines to configure GUEv1 static tunnels:

  • Configure the hw-module profile cef iptunnel scale command to increase the GUEv1 tunnel scale up to 12K tunnels. This tunnel scale can vary based on the number of ECMP tunnels used.

  • By default, up to 3500 GUEv1, MPLS over UDP, and IP-in-IP tunnels, including the number of Layer 3 interfaces, are supported.

  • Configure the nve overlay-encap guev1 udp-port destination command for IPv4, IPv6, and MPLS to send encapsulated overlay traffic to IPv4, IPv6, and MPLS destinations using UDP ports 6080, 6615, and 6635 respectively.

Restrictions for GUEv1 static tunnels

These restrictions are specific to the GUEv1 static tunnel configuration:

  • Traceroute over GUEv1 static tunnels is not supported in both uniform and pipe modes.

  • Non-default VRF is not supported for GUEv1 static tunnels.

Configure GUEv1 IPv4 and IPv6 static tunnels

Use the prefix mask remote-next-hop command to configure the IPv4 or IPv6 GUEv1 static tunnels.

Procedure

1.

Enter global configuration mode, and configure the IPv4 GUEv1 static tunnel.

Example:

Router# configure
Router(config)# router static
Router(config-static)# address-family ipv4 unicast
Router(config-static-afi)# 9.8.7.6/32 remote-next-hop 5.5.5.6 tunnel gue-v1 source-ip 1.1.1.1 dscp 46 ttl 250
Router(config-static-afi)# commit
2.

Configure the IPv6 GUEv1 static tunnel.

Example:

Router# configure
Router(config)# router static
Router(config-static)# address-family ipv6 unicast
Router(config-static-afi)# 11:1:1::1/128 remote-next-hop 10.10.10.11 tunnel gue-v1 source-ip 2.2.2.2 dscp 8 ttl 250
Router(config-static-afi)# commit
3.

Run the show running-config router static command to view the running configuration for the GUEv1 static tunnel.

Router# show running-config router static
Thu Mar 20 20:12:16.055 IST
router static
  address-family ipv4 unicast
    9.8.7.6/32 remote-next-hop 5.5.5.6 tunnel gue-v1 source-ip 1.1.1.1 dscp 46 ttl 250
  address-family ipv6 unicast
    11:1:1::1/128 remote-next-hop 10.10.10.11 tunnel gue-v1 source-ip 2.2.2.2 dscp 8 ttl 25
!
4.

Run the show static afi-all topology command to verify the IPv4 and IPv6 static routes.

Example:

Router# show static afi-all topology
Thu Mar 20 20:13:29.394 IST
IPv4 Unicast:
-------------
VRF: default Table Id: 0xe0000000 AFI: IPv4 SAFI: Unicast
Prefix/Len Interface Nexthop Object
Explicit-path Metrics Local-Label
127.127.127.8/32 None 11.11.11.2 None
None [0/0/1/0/0] No label

IPv6 Unicast:
-------------
VRF: default Table Id: 0xe0800000 AFI: IPv6 SAFI: Unicast
Prefix/Len Interface Nexthop Object
Explicit-path Metrics Local-Label
127:127:127::8/128 None 11.11.11.2 None
None [0/0/1/0/0] No label

You have configured IPv4 and IPv6 GUEv1 static tunnels. Configure the global UDP ports for GUEv1 static tunnels next.

Configure global UDP ports for GUEv1 static tunnels

Before you begin

Ensure that you have configured GUEv1 static tunnels.

This configuration enables the router to use GUEv1 as the overlay encapsulation type for network virtualization endpoint (NVE) and to send encapsulated overlay traffic to IPv4, IPv6, and MPLS destinations using UDP ports 6080, 6615, and 6635 respectively.

Procedure

1.

Enter global configuration mode and set the destination UDP port for the encapsulated packets to port 6080 on IPv4.

Example:

Router# configure
Router(config)# nve overlay-encap guev1 udp-port destination ipv4 6080
Router(config)# commit
2.

Set the destination UDP port for the encapsulated packets to port 6615 on IPv6.

Example:

Router(config)# nve overlay-encap guev1 udp-port destination ipv6 6615
Router(config)# commit
3.

Set the destination UDP port for the encapsulated packets to port 6635 for MPLS.

Example:

Router(config)# nve overlay-encap guev1 udp-port destination mpls 6635
Router(config)# commit
4.

Run the show running-config nve overlay-encap guev1 command to verify the configured UDP ports.

Example:

Router# show running-config nve overlay-encap guev1
Wed Nov 19 19:47:11.595 UTC
nve
 overlay-encap guev1
  udp-port destination ipv4 6080
  udp-port destination ipv6 6615
  udp-port destination mpls 6635
 !
!