Solved: Re: NCS 5001 Problem with sub-interface with encapsulation untagged - Page 2

jm-barreto · ‎03-07-2023

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.

jm-barreto · ‎03-09-2023

Hi Harold

I open a TAC ticket and get confirmation that encapsulation "untagged" is not supported.

I was able to confirm this is an expected behavior as the NCS5001 does not support untagged traffic under subinterfaces.

For a sub-interface to pass traffic it must be assigned with a 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

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

This can also be found on the following document.

https://www.cisco.com/c/en/us/td/docs/iosxr/ncs5000/vpn/73x/b-l2vpn-cg-ncs5000-73x/configure-virtual-LANs-in-iayer-2-VPNs.html#concept_8CAD55CE0DC04986976D129322C8AB15

“Before a sub-interface is allowed to pass traffic, it must have a valid tagging protocol encapsulation and VLAN identifier assigned.”

Thank you so much @Harold Ritter and @MHM Cisco World for your help and support

Harold Ritter · ‎03-09-2023

You are very welcome @jm-barreto and thanks for the feedback

Regards,
Harold Ritter, CCIE #4168 (EI, SP)

MHM Cisco World · ‎03-07-2023

Router(config)# l2vpn 
Router(config-l2vpn)# pw-class MHM
Router(config-l2vpn-pwc)# encapsulation mpls

can you add pw-class to l2vpn config, this ensure the frame is encapsulate with MPLS

Router(config)# l2vpn 
Router(config-l2vpn)# xconnect group Test
Router(config-l2vpn-xc)# p2p Test
Router(config-l2vpn-xc-p2p)# interface TenGigE0/0/0/5.10
Router(config-l2vpn-xc-p2p)# neighbor ipv4 10.0.0.1/2 pw-id 3555
Router(config-l2vpn-xc-p2p-pw)# pw-class MHM

jm-barreto · ‎03-07-2023

I could give it a try but as Harold mentioned it seems like 5001 dont support encapsulation "untagged"

Thanks for your help

MHM Cisco World · ‎03-07-2023

interface GigabitEthernet0/0/0/0.10 l2transport
encapsulation untagged
rewrite ingress push dot1q X symmetric

push is add tag and in reverse direction the tag will remove

also try this if you can.
thanks a lot