Description

Enabling Ultimate-Hop-Popping (UHP) on ACX7024 and ACX7100-48L, LSP goes down

 

Topology: ACX7024<>ACX7100-32C<>ACX7100-48L

 

 

###UHP has been disabled here, LSP is UP##

l2circuit {

   neighbor 2.2.2.2 {

       interface et-0/0/2.0 {

           virtual-circuit-id 1;

       }

   }

}

ldp {

   interface lo0.0;

}

mpls {

   statistics {

       file mpls_statistics size 100m files 10;

       interval 30;

       auto-bandwidth;

   }

   optimize-timer 300;

   exclude-srlg;

   inactive: ultimate-hop-popping;

   label-switched-path TO-ACX7100-48L-FROM-ACX7024-01 {

       to 2.2.2.2;

       inactive: no-self-ping;

       link-protection;

   }

   interface et-0/0/0.0;

   interface et-0/0/1.0;

}

 

root@acx7024# run show mpls lsp ingress brief                                           

Jul 22 16:55:48

Ingress LSP: 1 sessions

To             From           State Rt P    ActivePath      LSPname

2.2.2.2        3.3.3.3        Up    0 *                     TO-ACX7100-48L-FROM-ACX7024-01

Total 1 displayed, Up 1, Down 0

 

 

root@acx7024# run show rsvp session name TO-ACX7100-48L-FROM-ACX7024-01

Jul 22 16:55:49

Ingress RSVP: 3 sessions

To             From           State  Rt Style Labelin Labelout LSPname

2.2.2.2        3.3.3.3        Up      0 1 SE      -      38 TO-ACX7100-48L-FROM-ACX7024-01

Total 1 displayed, Up 1, Down 0

 

Egress RSVP: 2 sessions

Total 0 displayed, Up 0, Down 0

 

Transit RSVP: 0 sessions

Total 0 displayed, Up 0, Down 0

 

 

 

##Cleared the LSP ##

 

root@acx7024# run clear mpls lsp name TO-ACX7100-48L-FROM-ACX7024-01

Jul 22 16:56:43

 

[edit]

root@acx7024# run show mpls lsp ingress brief                          

Jul 22 16:56:50

Ingress LSP: 1 sessions

To             From           State Rt P    ActivePath      LSPname

2.2.2.2        3.3.3.3        Up    0 *                     TO-ACX7100-48L-FROM-ACX7024-01

Total 1 displayed, Up 1, Down 0

 

 192.168.1.2 S 192.168.4.1 S

    Received RRO (ProtectionFlag 1=Available 2=InUse 4=B/W 8=Node 10=SoftPreempt 20=Node-ID):

         1.1.1.1(flag=0x21) 192.168.1.2(flag=1 Label=36) 2.2.2.2(flag=0x20) 192.168.4.1(Label=3)

  183 Jul 22 16:56:45.317 Link-protection Up

  182 Jul 22 16:56:43.783 Record Route: 1.1.1.1(flag=0x21) 192.168.1.2(flag=1 Label=36) 2.2.2.2(flag=0x20) 192.168.4.1(Label=3)

  181 Jul 22 16:56:43.515 Selected as active path

  180 Jul 22 16:56:43.514 Self-ping ended successfully

  179 Jul 22 16:56:43.108 Up

  178 Jul 22 16:56:43.108 Self-ping started

  177 Jul 22 16:56:43.108 Self-ping enqueued

  176 Jul 22 16:56:43.108 Record Route: 1.1.1.1(flag=0x20) 192.168.1.2(Label=36) 2.2.2.2(flag=0x20) 192.168.4.1(Label=3)

  175 Jul 22 16:56:43.055 LSP-ID: 15 created

  174 Jul 22 16:56:43.055 Originate Call

  173 Jul 22 16:56:43.055 CSPF: computation result accepted 192.168.1.2 192.168.4.1

  172 Jul 22 16:56:43.055 Clear Call

  171 Jul 22 16:56:43.054 Deselected as active

  170 Jul 22 16:56:43.054 Link-protection Down

 

 

##Enabling UHP, clearing LSP session- LSP remains down##

 

root@acx7024# activate protocols mpls ultimate-hop-popping

Jul 22 16:58:44

 

[edit]

root@acx7024# commit

Jul 22 16:58:46

commit complete

 

[edit]

root@acx7024# run show mpls lsp ingress brief                                           

Jul 22 16:58:59

Ingress LSP: 1 sessions

To             From           State Rt P    ActivePath      LSPname

2.2.2.2        3.3.3.3        Up    0 *                     TO-ACX7100-48L-FROM-ACX7024-01

Total 1 displayed, Up 1, Down 0

 

[edit]

root@acx7024# run clear mpls lsp name TO-ACX7100-48L-FROM-ACX7024-01                    

Jul 22 16:59:10

 

[edit]

root@acx7024# run show mpls lsp ingress brief                          

Jul 22 16:59:15

Ingress LSP: 1 sessions

To             From           State Rt P    ActivePath      LSPname

2.2.2.2        3.3.3.3        Dn    0      -               TO-ACX7100-48L-FROM-ACX7024-01

Total 1 displayed, Up 0, Down 1

 

[edit]

root@acx7024# run show mpls lsp ingress brief   

Jul 22 16:59:32

Ingress LSP: 1 sessions

To             From           State Rt P    ActivePath      LSPname

2.2.2.2        3.3.3.3        Dn    0      -               TO-ACX7100-48L-FROM-ACX7024-01

Total 1 displayed, Up 0, Down 1

 

[edit]

root@acx7024# run show mpls lsp ingress brief   

Jul 22 16:59:43

Ingress LSP: 1 sessions

To             From           State Rt P    ActivePath      LSPname

2.2.2.2        3.3.3.3        Dn    0      -               TO-ACX7100-48L-FROM-ACX7024-01

Total 1 displayed, Up 0, Down 1

  192.168.1.2 S 192.168.4.1 S

    Received RRO (ProtectionFlag 1=Available 2=InUse 4=B/W 8=Node 10=SoftPreempt 20=Node-ID):

         1.1.1.1(flag=0x21) 192.168.1.2(flag=1 Label=38) 2.2.2.2(flag=0x20) 192.168.4.1(Label=28)

  203 Jul 22 16:59:10.784 Record Route: 1.1.1.1(flag=0x21) 192.168.1.2(flag=1 Label=38) 2.2.2.2(flag=0x20) 192.168.4.1(Label=28)

  202 Jul 22 16:59:10.282 Up

  201 Jul 22 16:59:10.282 Self-ping started

  200 Jul 22 16:59:10.282 Self-ping enqueued

  199 Jul 22 16:59:10.282 Record Route: 1.1.1.1(flag=0x20) 192.168.1.2(Label=38) 2.2.2.2(flag=0x20) 192.168.4.1(Label=28)

  198 Jul 22 16:59:10.231 LSP-ID: 17 created

  197 Jul 22 16:59:10.231 Originate Call

  196 Jul 22 16:59:10.231 CSPF: computation result accepted 192.168.1.2 192.168.4.1

  195 Jul 22 16:59:10.231 Self-ping ended due to LSP tear-down

  194 Jul 22 16:59:10.230 Clear Call

  193 Jul 22 16:59:10.230 Deselected as active

  192 Jul 22 16:59:10.230 Link-protection Down

  191 Jul 22 16:58:49.782 Record Route: 1.1.1.1(flag=0x21) 192.168.1.2(flag=1 Label=37) 2.2.2.2(flag=0x20) 192.168.3.1(Label=27)

  190 Jul 22 16:58:49.510 Up

  189 Jul 22 16:58:49.510 Self-ping started

  188 Jul 22 16:58:49.510 Self-ping enqueued

  187 Jul 22 16:58:49.510 Record Route: 1.1.1.1(flag=0x20) 192.168.1.2(Label=37) 2.2.2.2(flag=0x20) 192.168.3.1(Label=27)

  186 Jul 22 16:58:49.497 LSP-ID: 16 created

  185 Jul 22 16:58:49.497 Originate make-before-break call

  184 Jul 22 16:58:49.497 CSPF: computation result accepted 192.168.1.2 192.168.3.1

  183 Jul 22 16:56:45.317 Link-protection Up

 

 

Symptoms

LSP goes down if UHP is configured

Solution

All ACX (Junos+EVO) does not support Ultimate hop popping feature as confirmed under PR1825470.

There is also no future scope for this feature implementation.

Modification History

2024-08-28 : Article Created