topic Re: CFM CCM tagging issue in ExtremeSwitching (EXOS/Switch Engine)

CFM CCM tagging issue

Alexandr_P — Tue, 01 Dec 2020 21:28:26 GMT

Hello, colleagues!

Please give advice which way to look.

Scheme below:

X460G2 ↔ BD8810 ↔ X450a

X450a confgured with CFM, VLAN with CFM is tagged, but switch send CFM CCMs as untagged. Why so?

Below traces from BD8810 (there is traffic is double tagged - QinQ) - tcpdump -i eth2 -nn -e ether host 00:04:96:27:a9:b0

For example, ARP is normal (tagged with ID 3556)

18:44:10.774613 00:04:96:27:a9:b0 > ff:ff:ff:ff:ff:ff, ethertype 802.1Q (0x8100), length 68: vlan 1037, p 0, ethertype 802.1Q, vlan 3556, p 0, ethertype ARP, Request who-has 5.5.11.3 tell 5.5.11.1, length 46

But CFM CCM is untagged (only with second tag 1037)

18:44:11.436169 00:04:96:27:a9:b0 > 01:80:c2:00:00:33, ethertype 802.1Q (0x8100), length 101: vlan 1037, p 0, ethertype CFM, CFMv0 Continouity Check Message, MD Level 3, length 83

Config from X450a

create vlan "Q-in-Q_XXX"
configure vlan Q-in-Q_XXX tag 1037
create vlan "YYY-ctrl"
configure vlan YYY-ctrl tag 3556

……

configure vlan YYY-ctrl add ports 22-23 tagged

configure vlan YYY-ctrl ipaddress 5.5.11.1 255.255.255.0

……

#
# Module dot1ag configuration.
#
create cfm domain string "erps_rings" md-level 3
configure cfm domain "erps_rings" add association string "YYY" vlan "YYY-ctrl"
configure cfm domain "erps_rings" association "YYY" ports 22 add end-point down 6
configure cfm domain "erps_rings" association "YYY" ports 23 add end-point down 5
configure cfm domain "erps_rings" association "YYY" ports 23 end-point down add group "erpsYYYMain"
configure cfm domain "erps_rings" association "YYY" ports 22 end-point down add group "erpsYYYSlave"
configure cfm group "erpsYYYMain" add rmep 7
configure cfm group "erpsYYYSlave" add rmep 8

# sh vlan YYY-ctrl
VLAN Interface with name YYY-ctrl created by user
Admin State: Enabled Tagging: 802.1Q Tag 3556
Description: None
Virtual router: VR-Default
IPv4 Forwarding: Disabled
IPv4 MC Forwarding: Disabled
Primary IP: 5.5.11.1/24
IPv6 Forwarding: Disabled
IPv6 MC Forwarding: Disabled
IPv6: None
STPD: None
Protocol: Match all unfiltered protocols
Loopback: Disabled
NetLogin: Disabled
OpenFlow: Disabled
QosProfile: None configured
Egress Rate Limit Designated Port: None configured
Flood Rate Limit QosProfile: None configured
Ports: 2. (Number of active ports=2)
Tag: *22, *23

Thank you!

Re: CFM CCM tagging issue

Miguel-Angel_RO — Tue, 01 Dec 2020 21:35:22 GMT

Alexandr,

CFM has a specific ethertype, you cannot tag it as it is not 802.1Q (tagged frame):

For example, ARP is normal (tagged with ID 3556)

18:44:10.774613 00:04:96:27:a9:b0 > ff:ff:ff:ff:ff:ff, ethertype 802.1Q (0x8100), length 68: vlan 1037, p 0, ethertype 802.1Q, vlan 3556, p 0, ethertype ARP, Request who-has 5.5.11.3 tell 5.5.11.1, length 46

But CFM CCM is untagged (only with second tag 1037)

18:44:11.436169 00:04:96:27:a9:b0 > 01:80:c2:00:00:33, ethertype 802.1Q (0x8100), length 101: vlan 1037, p 0, ethertype CFM, CFMv0 Continouity Check Message, MD Level 3, length 83

Mig

Re: CFM CCM tagging issue

Alexandr_P — Tue, 01 Dec 2020 22:30:56 GMT

Below CFM packet received from other direction (second tag stripped) and we can see right tag (vlan YYY-ctrl - tag 3556 😞

16:04:02.273002 00:04:96:27:a9:b0 > 01:80:c2:00:00:33, ethertype 802.1Q (0x8100), length 101: vlan 3556, p 7, ethertype CFM, CFMv0 Continouity Check Message, MD Level 3, length 83

Through initial issued direction (through QinQ - where second tag 1037 is stripped) - we can’t see any tags:

16:08:25.251914 00:04:96:27:a9:b0 > 01:80:c2:00:00:33, ethertype CFM (0x8902), length 97: CFMv0 Continouity Check Message, MD Level 3, length 83

Also, below example right CFM CCM with 2 tags:

15:51:12.264262 00:04:96:27:99:02 > 01:80:c2:00:00:33, ethertype 802.1Q (0x8100), length 105: vlan 1198, p 0, ethertype 802.1Q, vlan 1352, p 7, ethertype CFM, CFMv0 Continouity Check Message, MD Level 3, length 83

Thank you!

Re: CFM CCM tagging issue

Alexandr_P — Tue, 01 Dec 2020 22:37:17 GMT

also you can see below picture with double tagged CFM CCM

Thank you!

Re: CFM CCM tagging issue

Miguel-Angel_RO — Wed, 02 Dec 2020 01:20:56 GMT

Alexandr,

Are you using ERPS in your config?

If so, there are additional commands for this kind of config like here: https://gtacknowledge.extremenetworks.com/articles/Solution/Discontinue-CFM-dynamic-creation-does-not-work-for-erps/

Mig

Re: CFM CCM tagging issue

Alexandr_P — Wed, 02 Dec 2020 16:27:20 GMT

Miguel!

Earlier ERPS was used. Now ERPS is deleted, so only CFM.

But your link still isn’t answer question - why CFM CCMs are untagged?

Your link is about “Dynamic creation of CFM to work with ERPS”. But in our case we manually create CFM and as you can sse CCMs is generated.

Thank you!

Re: CFM CCM tagging issue

Miguel-Angel_RO — Thu, 03 Dec 2020 01:53:03 GMT

Alexandr,

I’ve been looking for a doc describing better the CFM and this one is quite explicit: https://www.alliedtelesis.com/sites/default/files/documents/feature-guides/cfm_feature_overview_guide.pdf

There is probably an issue in the CFM config. Sending it as untag means Link level.

You should double check the configs on the X460, X450 and BD8810. On CFM level and on ports level.

Mig

Re: CFM CCM tagging issue

Alexandr_P — Thu, 03 Dec 2020 15:28:59 GMT

Hello, Miguel!

As you can see, in this switch, it’s 2 directions - to port 22 and 23

And through other channel (port 23) CFM frames are normally tagged:

16:04:02.273002 00:04:96:27:a9:b0 > 01:80:c2:00:00:33, ethertype 802.1Q (0x8100), length 101: vlan 3556, p 7, ethertype CFM, CFMv0 Continouity Check Message, MD Level 3, length 83

But through initial channel (port 22) CFM frames untagged:

16:08:25.251914 00:04:96:27:a9:b0 > 01:80:c2:00:00:33, ethertype CFM (0x8902), length 97: CFMv0 Continouity Check Message, MD Level 3, length 83

Thank you!

Re: CFM CCM tagging issue

Miguel-Angel_RO — Thu, 03 Dec 2020 23:47:48 GMT

Alexandr,

We miss a piece somewhere…

I suppose you configured vman for the QinQ.

Could you give the output of the following commands? (Some of them can be wrong, I don’t have an Exos to test them for the moment:

show vman
show vman <vman name>
show config | include vman
show ports 22,23 information detail
show version

Re: CFM CCM tagging issue

Alexandr_P — Thu, 03 Dec 2020 23:59:18 GMT

There is no VMAN configured on this X450a.

(Q-in-Q makes uplink ISP operator, so all packets received by this switch are with 1 tag)

(what reason for #sh version here?)

# sh ports 22 information detail
Port:   22

........
         VLAN cfg:
                  Name: YYY-devlan, 802.1Q Tag = 4052, MAC-limit =
No-limit, Virtual router:   VR-Default
                  Name: YYY-ctrl, 802.1Q Tag = 3556, MAC-limit =
No-limit, Virtual router:   VR-Default

Tnank you!

Re: CFM CCM tagging issue

Miguel-Angel_RO — Fri, 04 Dec 2020 00:00:54 GMT

Alexandr,

The reasion for the show version is because there are some constraints on CFM and vman based on the software release.

Mig

Re: CFM CCM tagging issue

Alexandr_P — Fri, 04 Dec 2020 00:02:40 GMT

-> show version
Switch : 800152-00-05 0000G-00000 Rev 5.0 BootROM: 1.0.2.2 IMG: 15.3.5.2
XGM2-1 :

Image : ExtremeXOS version 15.3.5.2 v1535b2-patch1-12 by release-manager
on Tue Sep 27 12:03:32 EDT 2016
BootROM : 1.0.2.2

Re: CFM CCM tagging issue

Miguel-Angel_RO — Fri, 04 Dec 2020 00:11:02 GMT

Alexandr,

I’m lost with the different pieces of config and explanations and what port belongs to what switch .

Could you provide a small topology diagram pointing on what port, what trafic direction you see the issue?

The purpose is to identify where we need to debug, X460, BD8810 or X450.

A show config of the three switches would help.

Some questions to clarify:

Are the X460 and X450 doing QinQ?
Is the BD8810 doing QinQ?
Why do you need the QinQ seen in the captures?

Mig

Re: CFM CCM tagging issue

Alexandr_P — Fri, 04 Dec 2020 17:12:19 GMT

Hello, Miguel!

Are the X460 and X450 doing QinQ? - no
Is the BD8810 doing QinQ? - no.
Why do you need the QinQ seen in the captures? - beause packet captures makes in BD8810, through BD8810 traversing traffic with 2 tags. Upstream ISP make second tag for egress (from X450) traffic and strip second tag for ingress traffic.

Actually - there is no matter who makes Q-in-Q, because mane issue that X450a didn’t tagging CFM CCM. (port 22 in X450a is tagged with Vlan YYY-ctrl, but CFM CCM frames are untagged - without tag 3556)

Below scheme:

Thank you!

Re: CFM CCM tagging issue

Miguel-Angel_RO — Fri, 04 Dec 2020 17:28:42 GMT

Ok, we have the global picture.

We’ll compare the x460 and x450 config knowing that the difference in firmware could get a different syntax.

Could we have the following output:

X450:
- show ports 22,23 information detail
- the full output is needed
x460
- show ports 17,18 information detail
from both:
- show port vlan port
  - the output of port 22,23 for x450 and 17,18 for x460 is enough
- show cfm
- show cfm detail
- show cfm <domain_name>
- show cfm groups

Mig

Re: CFM CCM tagging issue

Alexandr_P — Fri, 04 Dec 2020 20:57:53 GMT

What do you mean in “show port vlan port”?

# show ports vlan
statistics statistics

# show ports 22 vlan
statistics statistics

Thank you!

Re: CFM CCM tagging issue

Miguel-Angel_RO — Fri, 04 Dec 2020 21:04:59 GMT

Like this:

* X435-8P-2T-W.1 # show ports vlan port-number Untagged Port /Tagged VLAN Name(s) -------- -------- ------------------------------------------------------------ 1 Untagged Default 2 Untagged Default 3 Untagged Default 4 Untagged Default 5 Untagged None Tagged Default, VLAN_0010 6 Untagged Default 7 Untagged None Tagged EAPS_CONTROL, VLAN_0010 8 Untagged None Tagged EAPS_CONTROL, VLAN_0010 9 Untagged Default Tagged VLAN_0010 10 Untagged Default * X435-8P-2T-W.2 #

Mig

Re: CFM CCM tagging issue

Alexandr_P — Fri, 04 Dec 2020 21:23:01 GMT

This command unavailable in earlier EXOS (on X460 and X450)

Thank you!

Re: CFM CCM tagging issue

Miguel-Angel_RO — Fri, 04 Dec 2020 21:26:39 GMT

Let’s start with the other commands.

Mig