NCS 5001 Problem with sub-interface with encapsulation untagged

[jm-barreto]

Hi

I'm having trouble configuring sub-interfaces and interfaces with encapsulation untagged on the NCS 5001.

I have 2 NCS 5001 connected with OSPF/MPLS. I have a l2vpn on ports 0/0/0/0 on each 5001 two test computers. The xconnect is up but I can't communicate between the test equipment.

I have no problems when it is encapsultation tag or default. I only have problems in encapsultation untagged.

I have already made this type of configuration in NCS 540 and ASR 9006 and I have no problems.

Here is the configuration on both 5001

interface GigabitEthernet0/0/0/0
description Test
mtu 1546
negotiation auto
!
interface GigabitEthernet0/0/0/0.10 l2transport
encapsulation untagged
mtu 1546
!

l2vpn
router-id 10.1.1.1
xconnect group Test
p2p TEST
interface GigabitEthernet0/0/0/0.10
neighbor ipv4 10.1.1.2 pw-id 3555




RP/0/RP0/CPU0:ios#sh l2vpn xc pw-id 3555 detail
Tue Mar 7 18:30:14.972 UTC

Group Test, XC TEST, state is up; Interworking none
AC: GigabitEthernet0/0/0/0.10, state is up
Type VLAN; Num Ranges: 0
Rewrite Tags: []
MTU 1532; XC ID 0x1; interworking none
Statistics:
packets: received 0, sent 0
bytes: received 0, sent 0
drops: illegal VLAN 0, illegal length 0
PW: neighbor 10.1.1.1, PW ID 3555, state is up ( established )
PW class not set, XC ID 0xc0000001
Encapsulation MPLS, protocol LDP
Source address 10.1.1.2
PW type Ethernet, control word disabled, interworking none
PW backup disable delay 0 sec
Sequencing not set
Ignore MTU mismatch: Disabled
Transmit MTU zero: Disabled
LSP : Up

PW Status TLV in use
MPLS Local Remote
------------ ------------------------------ -----------------------------
Label 24001 24001
Group ID 0x80002e8 0x80002e8
Interface GigabitEthernet0/0/0/0.10 GigabitEthernet0/0/0/0.10
MTU 1532 1532
Control word disabled disabled
PW type Ethernet Ethernet
VCCV CV type 0x2 0x2
(LSP ping verification) (LSP ping verification)
VCCV CC type 0x6 0x6
(router alert label) (router alert label)
(TTL expiry) (TTL expiry)
------------ ------------------------------ -----------------------------
Incoming Status (PW Status TLV):
Status code: 0x0 (Up) in Notification message
Outgoing Status (PW Status TLV):
Status code: 0x0 (Up) in Notification message
MIB cpwVcIndex: 3221225473
Create time: 07/03/2023 02:34:00 (1d00h ago)
Last time status changed: 08/03/2023 03:02:36 (00:05:41 ago)
Last time PW went down: 07/03/2023 04:47:02 (22:21:16 ago)
Statistics:
packets: received 0, sent 0
bytes: received 0, sent 0
RP/0/RP0/CPU0:ios#sh l2vpn xc pw-id 3555 detail
Wed Mar 8 03:08:37.231 UTC

Group Test, XC TEST, state is up; Interworking none
AC: GigabitEthernet0/0/0/0.10, state is up
Type VLAN; Num Ranges: 0
Rewrite Tags: []
MTU 1532; XC ID 0x1; interworking none
Statistics:
packets: received 0, sent 0
bytes: received 0, sent 0
drops: illegal VLAN 0, illegal length 0
PW: neighbor 10.1.1.1, PW ID 3555, state is up ( established )
PW class not set, XC ID 0xc0000001
Encapsulation MPLS, protocol LDP
Source address 10.1.1.2
PW type Ethernet, control word disabled, interworking none
PW backup disable delay 0 sec
Sequencing not set
Ignore MTU mismatch: Disabled
Transmit MTU zero: Disabled
LSP : Up

PW Status TLV in use
MPLS Local Remote
------------ ------------------------------ -----------------------------
Label 24001 24001
Group ID 0x80002e8 0x80002e8
Interface GigabitEthernet0/0/0/0.10 GigabitEthernet0/0/0/0.10
MTU 1532 1532
Control word disabled disabled
PW type Ethernet Ethernet
VCCV CV type 0x2 0x2
(LSP ping verification) (LSP ping verification)
VCCV CC type 0x6 0x6
(router alert label) (router alert label)
(TTL expiry) (TTL expiry)
------------ ------------------------------ -----------------------------
Incoming Status (PW Status TLV):
Status code: 0x0 (Up) in Notification message
Outgoing Status (PW Status TLV):
Status code: 0x0 (Up) in Notification message
MIB cpwVcIndex: 3221225473
Create time: 07/03/2023 02:34:00 (1d00h ago)
Last time status changed: 08/03/2023 03:02:36 (00:06:00 ago)
Last time PW went down: 07/03/2023 04:47:02 (22:21:35 ago)
Statistics:
packets: received 0, sent 0
bytes: received 0, sent 0




GigabitEthernet0/0/0/0 is up, line protocol is up
Interface state transitions: 11
Hardware is GigabitEthernet, address is 5ca6.2d67.ca06 (bia 5ca6.2d67.ca06)
Description: Test
Internet address is Unknown
MTU 1546 bytes, BW 1000000 Kbit (Max: 1000000 Kbit)
reliability 255/255, txload 0/255, rxload 0/255
Encapsulation ARPA,
Full-duplex, 1000Mb/s, SXFD, link type is autonegotiation
output flow control is off, input flow control is off
Carrier delay (up) is 10 msec
loopback not set,
Last link flapped 14:32:39
Last input 00:00:05, output never
Last clearing of "show interface" counters never
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
11888 packets input, 3784056 bytes, 0 total input drops
44 drops for unrecognized upper-level protocol
Received 78 broadcast packets, 11810 multicast packets
0 runts, 0 giants, 0 throttles, 0 parity
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
0 packets output, 0 bytes, 0 total output drops
Output 0 broadcast packets, 0 multicast packets
0 output errors, 0 underruns, 0 applique, 0 resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions

Like i commented before i have done this type of configuration on NCS-540 and ASR9006 and have no issue. Is there something i missing in the configuration?

I appreciate any help you can provide.

[Harold Ritter]

Hi @jm-barreto ,

The IOS-XR version you are running on the NCS5001 might not support it. According to the documentation

encapsulation untagged

was introduced in 6.0.1. What version are you running?

Regards,

[jm-barreto]

Hi

Im running in firmware 7.3.2.

[Harold Ritter]

Hi @jm-barreto ,

Thanks for the additional information. Can you validate that the test device does not generate tagged traffic. Can you also provide the

show interface gi0/0/0/0.10

output?

Regards,

[jm-barreto]

Hi

Thanks for your help

The test device are 2 laptop and im not tagging any vlan on those laptops. I also try with 2 Exfo without tagging any vlan. But im running the test now with 2 laptops 

GigabitEthernet0/0/0/0.10 is up, line protocol is up
Interface state transitions: 11
Hardware is VLAN sub-interface(s), address is 5ca6.2d67.ca06
Layer 2 Transport Mode
MTU 1546 bytes, BW 1000000 Kbit (Max: 1000000 Kbit)
reliability Unknown, txload Unknown, rxload Unknown
Encapsulation Untagged,
Match untagged
Ethertype Any, MAC Match src any, dest any
loopback not set,
Last link flapped 20:39:34
Last input never, output never
Last clearing of "show interface" counters never
0 packets input, 0 bytes
0 input drops, 0 queue drops, 0 input errors
0 packets output, 0 bytes
0 output drops, 0 queue drops, 0 output errors

[MHM Cisco World]

as I know

interface GigabitEthernet0/0/0/0.10 l2transport
encapsulation untagged
mtu 1546
!

instead of above change config to be 

encapsulation dot1q X

tag that receive from CE 

rewrite ingress pop dot1q X symmetric 

which meaning Router will remove the tag and forward without tag egress and add tag for ingress

[jm-barreto]

Hi

In this scenario Im not receiving any tag, both ends are "access". I want encapsulation untagged on both ends. 

[jm-barreto]

I can do this type of configuration on NCS540 and ASR9006. Even though I can configure on NCS 5001, its not passing traffic. 

[MHM Cisco World]

Only one subinterface may be configured as encapsulation untagged. This interface is referred to as the untagged subinterface or untagged EFP (incase of an L2 interface). 
Is this subinterface is only one that untag or there is other subinterface, I am talking about subinterface in same parent interface. 

[jm-barreto]

Yes. Im aware that only 1 sub-interface can be untagged. This is a test environment so i have only 1 sub-interface configure. No other sub-interface is configured

[MHM Cisco World]

Router#show l2vpn xconnect group Test 

please share the output for both side  

[jm-barreto]

Router 1

0/CPU0:ios#sh l2vpn xc group Test

Wed Mar 8 01:59:04.306 UTC

Legend: ST = State, UP = Up, DN = Down, AD = Admin Down, UR = Unresolved,

        SB = Standby, SR = Standby Ready, (PP) = Partially Programmed,

        LU = Local Up, RU = Remote Up, CO = Connected

XConnect Segment 1 Segment 2

Group Name ST Description ST Description ST

------------------------ ----------------------------- -----------------------------

Test TEST UP Gi0/0/0/0.10 UP 10.1.1.2 3555 UP

----------------------------------------------------------------------------------------

RP/0/RP0/CPU0:ios#sh l2vpn xc group Test detail

Wed Mar 8 01:59:16.267 UTC

Group Test, XC TEST, state is up; Interworking none

  AC: GigabitEthernet0/0/0/0.10, state is up

    Type VLAN; Num Ranges: 0

    Rewrite Tags: []

    MTU 1532; XC ID 0x1; interworking none

    Statistics:

      packets: received 0, sent 0

      bytes: received 0, sent 0

      drops: illegal VLAN 0, illegal length 0

  PW: neighbor 10.1.1.2, PW ID 3555, state is up ( established )

    PW class not set, XC ID 0xc0000001

    Encapsulation MPLS, protocol LDP

    Source address 10.1.1.1

    PW type Ethernet, control word disabled, interworking none

    PW backup disable delay 0 sec

    Sequencing not set

    Ignore MTU mismatch: Disabled

    Transmit MTU zero: Disabled

    LSP : Up

    PW Status TLV in use

      MPLS Local Remote

      ------------ ------------------------------ -----------------------------

      Label 24001 24001

      Group ID 0x80002e8 0x80002e8

      Interface GigabitEthernet0/0/0/0.10 GigabitEthernet0/0/0/0.10

      MTU 1532 1532

      Control word disabled disabled

      PW type Ethernet Ethernet

      VCCV CV type 0x2 0x2

                   (LSP ping verification) (LSP ping verification)

      VCCV CC type 0x6 0x6

                   (router alert label) (router alert label)

                   (TTL expiry) (TTL expiry)

      ------------ ------------------------------ -----------------------------

    Incoming Status (PW Status TLV):

      Status code: 0x0 (Up) in Notification message

    Outgoing Status (PW Status TLV):

      Status code: 0x0 (Up) in Notification message

    MIB cpwVcIndex: 3221225473

    Create time: 06/03/2023 20:29:12 (1d05h ago)

    Last time status changed: 07/03/2023 20:58:24 (05:00:52 ago)

    Last time PW went down: 06/03/2023 22:42:52 (1d03h ago)

    Statistics:

      packets: received 0, sent 0

      bytes: received 0, sent 0













Router 2

/0/RP0/CPU0:ios#sh l2vpn xconnect group Test

Wed Mar 8 08:07:16.017 UTC

Legend: ST = State, UP = Up, DN = Down, AD = Admin Down, UR = Unresolved,

        SB = Standby, SR = Standby Ready, (PP) = Partially Programmed,

        LU = Local Up, RU = Remote Up, CO = Connected

XConnect Segment 1 Segment 2

Group Name ST Description ST Description ST

------------------------ ----------------------------- -----------------------------

Test TEST UP Gi0/0/0/0.10 UP 10.1.1.1 3555 UP

----------------------------------------------------------------------------------------







RP/0/RP0/CPU0:

RP/0/RP0/CPU0:ios#




RP/0/RP0/CPU0:ios#




RP/0/RP0

RP/0/RP0/CPU0:ios#sh l2vpn xconnect group Test detail

Wed Mar 8 08:08:27.176 UTC

Group Test, XC TEST, state is up; Interworking none

  AC: GigabitEthernet0/0/0/0.10, state is up

    Type VLAN; Num Ranges: 0

    Rewrite Tags: []

    MTU 1532; XC ID 0x1; interworking none

    Statistics:

      packets: received 0, sent 0

      bytes: received 0, sent 0

      drops: illegal VLAN 0, illegal length 0

  PW: neighbor 10.1.1.1, PW ID 3555, state is up ( established )

    PW class not set, XC ID 0xc0000001

    Encapsulation MPLS, protocol LDP

    Source address 10.1.1.2

    PW type Ethernet, control word disabled, interworking none

    PW backup disable delay 0 sec

    Sequencing not set

    Ignore MTU mismatch: Disabled

    Transmit MTU zero: Disabled

    LSP : Up

    PW Status TLV in use

      MPLS Local Remote

      ------------ ------------------------------ -----------------------------

      Label 24001 24001

      Group ID 0x80002e8 0x80002e8

      Interface GigabitEthernet0/0/0/0.10 GigabitEthernet0/0/0/0.10

      MTU 1532 1532

      Control word disabled disabled

      PW type Ethernet Ethernet

      VCCV CV type 0x2 0x2

                   (LSP ping verification) (LSP ping verification)

      VCCV CC type 0x6 0x6

                   (router alert label) (router alert label)

                   (TTL expiry) (TTL expiry)

      ------------ ------------------------------ -----------------------------

    Incoming Status (PW Status TLV):

      Status code: 0x0 (Up) in Notification message

    Outgoing Status (PW Status TLV):

      Status code: 0x0 (Up) in Notification message

    MIB cpwVcIndex: 3221225473

 --More--

Group Test, XC TEST, state is up; Interworking none

  AC: GigabitEthernet0/0/0/0.10, state is up

    Type VLAN; Num Ranges: 0

    Rewrite Tags: []

    MTU 1532; XC ID 0x1; interworking none

    Statistics:

      packets: received 0, sent 0

      bytes: received 0, sent 0

      drops: illegal VLAN 0, illegal length 0

  PW: neighbor 10.1.1.1, PW ID 3555, state is up ( established )

    PW class not set, XC ID 0xc0000001

    Encapsulation MPLS, protocol LDP

    Source address 10.1.1.2

    PW type Ethernet, control word disabled, interworking none

    PW backup disable delay 0 sec

    Sequencing not set

    Ignore MTU mismatch: Disabled

    Transmit MTU zero: Disabled

    LSP : Up

    PW Status TLV in use

      MPLS Local Remote

      ------------ ------------------------------ -----------------------------

      Label 24001 24001

      Group ID 0x80002e8 0x80002e8

      Interface GigabitEthernet0/0/0/0.10 GigabitEthernet0/0/0/0.10

      MTU 1532 1532

      Control word disabled disabled

      PW type Ethernet Ethernet

      VCCV CV type 0x2 0x2

                   (LSP ping verification) (LSP ping verification)

      VCCV CC type 0x6 0x6

                   (router alert label) (router alert label)

                   (TTL expiry) (TTL expiry)

      ------------ ------------------------------ -----------------------------

    Incoming Status (PW Status TLV):

      Status code: 0x0 (Up) in Notification message

    Outgoing Status (PW Status TLV):

      Status code: 0x0 (Up) in Notification message

    MIB cpwVcIndex: 3221225473

    Create time: 07/03/2023 02:34:00 (1d05h ago)

    Last time status changed: 08/03/2023 03:02:36 (05:05:50 ago)

    Last time PW went down: 07/03/2023 04:47:02 (1d03h ago)

    Statistics:

      packets: received 0, sent 0

      bytes: received 0, sent 0

RP/0/RP0/CPU0:ios#

[Harold Ritter · Accepted solution]

Hi @jm-barreto ,

I found internal information stating that

encapsulation untagged and encapsulation default 

are not actually supported on the NCS5001 and NCS5002 due to platform limitations.

Regards,

[jm-barreto]

Oh wow. Even though i can enter the commands? It there any official documentation with this information so i can show this to my team?

Really appreciate your help

[Harold Ritter]

Hi @jm-barreto ,

The only external information I could find is from the following document. Although it doesn't explicitly state that encapsulation untagged or default are not supported, but internal information does leave any doubt.

"A subinterface does not pass traffic without an assigned VLAN ID."

https://www.cisco.com/c/en/us/td/docs/iosxr/ncs5000/interfaces/b-ncs5000-interfaces-cli-reference/b-ncs5000-interfaces-cli-reference_chapter_0110.html

Regards,