LACP not negotiating properly

[MysticalTh0r]

Hello all,

We have a customer who is trying to create a 2 gig ports Port-Channel with our router and the LACP is not working. When we force the mode ON on both sides of the port-channel it works and we have connectivity but as soon as we change the mode to LACP (channel-group 1 mode active) it doesn't work.

What I see from the debugs from LACP on customer's site is that they router (ASR 1001, IOS-XE 3.7.5) sometimes sends an "all zero" mac-address, while on our side we always send our MAC address (ASR 1001-X, IOS-XE 3.16.6).

Here are the debugs:

Mar 20 09:39:26.751: LACP :lacp_bugpak: Send LACP-PDU packet via Gi0/0/1
Mar 20 09:39:26.751: LACP : packet size: 124
Mar 20 09:39:26.751: LACP: pdu: subtype: 1, version: 1
Mar 20 09:39:26.751: LACP: Act: tlv:1, tlv-len:20, key:0x0, p-pri:0x8000, p:0x2, p-state:0x41,
s-pri:0x8000, s-mac:0abc.cdef.0abc
Mar 20 09:39:26.751: LACP: Part: tlv:2, tlv-len:20, key:0x0, p-pri:0x0, p:0x0, p-state:0x0,
s-pri:0x0, s-mac:0000.0000.0000
Mar 20 09:39:26.751: LACP: col-tlv:3, col-tlv-len:16, col-max-d:0x8000
Mar 20 09:39:26.751: LACP: term-tlv:0 termr-tlv-len:0
Mar 20 09:39:26.751: LACP: HA: Attempt to sync events -- no action (event type 0x1)
Mar 20 09:39:26.751: LACP: HA: Attempt to sync events -- no action (event type 0x1)
Mar 20 10:39:26.750: %LINK-3-UPDOWN: SIP0/0: Interface GigabitEthernet0/0/1, changed state to down
Mar 20 10:39:29.652: %LINK-3-UPDOWN: Interface GigabitEthernet0/0/1, changed state to up
Mar 20 09:39:29.653: LACP :lacp_bugpak: Send LACP-PDU packet via Gi0/0/1

Any idea about why the LACP is not working and why they send all-zero mac addresses ? Thanks,

By the way, I've tested on lab and ASR1001 with IOS-XE 3.7.5 peering with an ASR 1001-X with IOS-XE 3.16.6 and it works fine. 

Thanks,

Best regards.

[Mark Malone]

Hi
Check the LACP counters see which side is at fault , see if there both sending and actually receiving packets

show LACP counters

[MysticalTh0r]

Thanks for the reply,

It's not possible to see the LACP counters at the moment as the customer decided to configure de Po with "mode ON" but he wants to know how to fix the LACP problem since it has to be configured with this protocol in the end. To see if LACP packets are sent and received isn't enough with the debug? I see this messages:

LACP :lacp_bugpak: Send LACP-PDU packet via Gi0/1/7

(...)

LACP :lacp_bugpak: Receive LACP-PDU packet via Gi0/1/7

Any ideas why we see the MAC address sent as 0000.0000.0000?

Thanks,

Best regards

[Mark Malone · Accepted solution]

Hi
The counters will show whats received and sent and how there talking , if 1 side is lot less than the other theres an issue there , ive had issues with devices not sending packets back to to the other unit even when configured correctly or only sending some

if its working in ON state the issue is to do with the negotiation between the devices if there configured right , i cant tell whats wrong from that debug theres nothing valid in it to pull from

if the customer wants it on LACP tell them to put it back so you can troubleshoot it and fix it , or tell him you'll change your side to match ON ,you cant be expected you to fix something you cant troubleshoot

all mac zero usually mean bad NIC but i dont see anything in your outputs to show where or how that was seen to say for certain ,


example of counters packets should match nearly between both sides
LACPDUs Marker Marker Response LACPDUs
Port Sent Recv Sent Recv Sent Recv Pkts Err
---------------------------------------------------------------------
port-channel1
Ethernet1/45 680037 680035 0 0 0 0 0
Ethernet1/46 680037 680034 0 0 0 0 0
Ethernet1/47 680038 680035 0 0 0 0 0
Ethernet1/48 680040 680033 0 0 0 0 0

[MysticalTh0r]

Hi,

True, if I can't see I can't "guess" the source of the problem. I'll try to get a mainteinance window to troubleshoot this and post the results here. Thanks.

Best regards.

[MysticalTh0r]

Hi,

Finally the customer wants to keep the mode ON active, so no chance to troubleshoot...Thanks anyway.