Description

Customer is using ACX EVO device with version 24.2R1-EVO. They wanted to build a GRE tunnel with ISP.

The ISP will be using GRE tunnel at their side.

Symptoms

Earlier, GRE encap was not available for ACX EVO.

Even with this feature, you cannot configure GRE tunnel, but only FTI with GRE encap.

Solution

The new feature "MPLS over GRE - FTI" is introduced in ACX EVO platforms from 24.2R1.

https://apps.juniper.net/feature-explorer/feature/8081?fn=MPLS%20over%20GRE%20-%20FTI

Allows you to configure MPLS protocols over FTI (flexible tunnel interface), thereby transporting MPLS packets over IP networks which do not support MPLS. GRE and UDP tunnels support MPLS protocol for both IPv4 and IPv6 traffic. You can configure encapsulation and de-encapsulation for the GRE and UDP tunnels.

 

Below is the sample configuration, which was tested in lab with topology, ACX7024 <-10G-> MX104.

 

ACX7024

set chassis fpc 0 pic 0 tunnel-services

set interfaces et-0/0/4 description mx104-xe-0/0/0

set interfaces et-0/0/4 unit 0 family inet address 10.10.10.0/31

set interfaces fti1 unit 0 tunnel encapsulation gre source address 1.1.1.1

set interfaces fti1 unit 0 tunnel encapsulation gre destination address 2.2.2.2

set interfaces fti1 unit 0 tunnel encapsulation gre bypass-loopback

set interfaces fti1 unit 0 tunnel encapsulation gre ttl 255

set interfaces fti1 unit 0 family inet address 3.3.3.0/31

set routing-options static route 2.2.2.2/32 next-hop 10.10.10.1

 

MX104

set chassis fpc 0 pic 0 tunnel-services

set interfaces gr-0/0/0 unit 0 tunnel source 2.2.2.2

set interfaces gr-0/0/0 unit 0 tunnel destination 1.1.1.1

set interfaces gr-0/0/0 unit 0 family inet address 3.3.3.1/31

set interfaces xe-0/0/0 description acx7024-et-0/0/4

set interfaces xe-0/0/0 unit 0 family inet address 10.10.10.1/31

set routing-options static route 1.1.1.1/32 next-hop 10.10.10.0

 

Result:

labroot@jtac-acx7024-r2005> ping 3.3.3.1                     

PING 3.3.3.1 (3.3.3.1) 56(84) bytes of data.

64 bytes from 3.3.3.1: icmp_seq=1 ttl=64 time=1.34 ms

64 bytes from 3.3.3.1: icmp_seq=2 ttl=64 time=1.50 ms

 |

labroot@jtac-acx7024-r2005> show interfaces fti1 detail 

Physical interface: fti1, Enabled, Physical link is Up

<snip>

 Logical interface fti1.0 (Index 1001) (SNMP ifIndex 551) (Generation 614180324398)

  Flags: Up Point-To-Point Encapsulation: GRE DF

     , Source address: 1.1.1.1/32, Destination address: 2.2.2.2

<snip>

  Local statistics:

  Input bytes :       5508540

  Output bytes :       5508540

  Input packets:        51005

  Output packets:        51005

 |

labroot@jtac-mx104-r2017-re0> show interfaces gr-0/0/0 detail           

Physical interface: gr-0/0/0, Enabled, Physical link is Up

<snip>

 Logical interface gr-0/0/0.0 (Index 321) (SNMP ifIndex 580) (Generation 194)

  Flags: Up Point-To-Point SNMP-Traps 0x0 IP-Header 1.1.1.1:2.2.2.2:47:df:64:0000000000000000 Encapsulation: GRE-NULL

<snip>

  Traffic statistics:

   Input bytes :       4348932

   Output bytes :       5511240

   Input packets:        51773

   Output packets:        51030

  Local statistics:

   Input bytes :       4284420

   Output bytes :       5511240

   Input packets:        51005

   Output packets:        51030

Modification History

2024-10-10 : Article Created