Description

The SWAP operation doesn't seems to be working as expected in ACX-EVO platform.




Symptoms

Here is an example output from an MX Junos device

set interfaces ae63 unit 3900 encapsulation vlan-vpls

set interfaces ae63 unit 3900 vlan-id 696

set interfaces ae63 unit 3900 swap-by-poppush

set interfaces ae63 unit 3900 family vpls

|

Logical interface ae63.3900 (Index 4688) (SNMP ifIndex 2465) (Generation 4589)

Flags: Up Promiscuous SNMP-Traps 0x4000 VLAN-Tag [ 0x8100.696 ] In(swap .3900) Out(swap .696) Encapsulation: VLAN-VPLS

 

Here is one of the many EVO configs

set interfaces ae30 unit 3910 encapsulation vlan-vpls

set interfaces ae30 unit 3910 vlan-id 661

set interfaces ae30 unit 3910 input-vlan-map swap

set interfaces ae30 unit 3910 output-vlan-map swap

set routing-instances TEST protocols vpls site test-1 interface ae30.3910

set routing-instances TEST interface ae30.3910

|

Logical interface ae30.3910 (Index 1057) (SNMP ifIndex 532)

Flags: Up SNMP-Traps VLAN-Tag[ 0x8100.661 ] In(swap .661) Out(swap .661) Encapsulation: VLAN-VPLS DF

Solution

In MX, swap-by-poppush, refer to replace any tagged frame with new vlan defined for the interface.

"Pop original tag, then push an entirely new tag. The swap operation is performed as pop followed by push."

But this knob is not available in ACX EVO.

 

After removing vlan input/output maps & changing the vlan id in instance, the ping worked fine.

So basically we are normalising the vlan here, with 3910 as the vlan in instance & 661 vlan in interface.

With this, instance will have vlan 3910 & interface will have swap vlan 661.

 

This will work fine when only one OG interface/VLAN is to be swapped, inside the instance.

If there are multiple interfaces/VLANs are present, customer can go for VLAN normalisation.

 

Changes:

set interfaces ae30 unit 3910 encapsulation vlan-vpls

set interfaces ae30 unit 3910 vlan-id 661

set routing-instances TEST vlans VLAN661 vlan-id 3910

set routing-instances TEST vlans VLAN661 interface ae30.3910

 

LAB ACX config:

set routing-instances TEST instance-type virtual-switch

set routing-instances TEST protocols vpls site site1 interface ae30.3910

set routing-instances TEST protocols vpls site site1 site-identifier 6610

set routing-instances TEST protocols vpls site site1 site-preference primary

set routing-instances TEST protocols vpls no-tunnel-services

set routing-instances TEST protocols vpls mac-flush

set routing-instances TEST interface ae30.3910

set routing-instances TEST route-distinguisher a.b.c.d:xxx

set routing-instances TEST vrf-target target:xxx:yyy

set routing-instances TEST vlans VLAN661 vlan-id 3910

set routing-instances TEST vlans VLAN661 interface ae30.3910

|

set interfaces ae30 enable

set interfaces ae30 flexible-vlan-tagging

set interfaces ae30 encapsulation flexible-ethernet-services

set interfaces ae30 aggregated-ether-options link-speed 10g

set interfaces ae30 aggregated-ether-options lacp active

set interfaces ae30 aggregated-ether-options ethernet-switch-profile tag-protocol-id 0x8100

set interfaces ae30 aggregated-ether-options ethernet-switch-profile tag-protocol-id 0x88a8

set interfaces ae30 unit 3910 encapsulation vlan-vpls

set interfaces ae30 unit 3910 vlan-id 661

 

LAB:

labroot@jtac-acx7100-48l-ao-r2023> show ethernet-switching table instance TEST               

<snip>

Ethernet switching table : 2 entries, 2 learned

Routing instance : TEST

   Vlan               MAC                MAC        Age  GBP    Logical               NH       RTR

    name               address            flags            Tag    interface             Index    ID

   VLAN661            00:00:05:a7:6b:00  D            -           lsi.1048832           0        0      

    VLAN661            4c:6d:58:25:e9:41  D            -           ae30.3910             0        0      

|

labroot@jtac-mx104-r2016-re0> show vpls mac-table instance TEST   

<snip>

Routing instance : TEST

Bridging domain : __TEST__, VLAN : NA

  MAC                MAC     Logical         NH    MAC        active

  address            flags   interface       Index property   source

  00:00:05:a7:6b:00  D       xe-2/0/1.3910  

   4c:6d:58:25:e9:41  D       lsi.1048832  

|

labroot@jtac-acx7100-48l-ao-r2023> show interfaces ae30.3910

  Logical interface ae30.3910 (Index 1068) (SNMP ifIndex 546)

    Flags: Up SNMP-Traps VLAN-Tag[ 0x8100.661 ]  In(swap .3910) Out(swap .661)  Encapsulation: VLAN-VPLS DF

Modification History

2024-12-20 : Article Created