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Port-Cannel troubleshooting commands debug
I am looking for in-depth commands for troubleshooting Port-Cannel.
The issue is that I have been tasked with making a L2 LAG to switches that are physically separated by 3,000 miles. I fully understand this is unheard of but this is my task.
To add to the fun the two links are with different providers and have different latency.
Surprise surprise I am unable to get both links in the LAG at the same time. This is what I expected but I want to know exactly why this is happening....PDU not arriving, packets out of order.......
What commands do you use to get the factual data to why?
< show lacp XXX counters >
Does no really help me that much
< show lacp XX >
Seems like this has a lot of good data but, its hard to read. For example, when comparing it to a good Port-Channel the "State" has a "H" indicating "H - OUT_OF_SYNC" but that PC is working and has been working for years.
and who is the "Actor" and who is the "Partner" ? is there a white paper explaining the command < show lacp XX >
< debug lacp pdu >
I can see that pdu's are being sent. I can also see the "State" is 3f. What are the states and their meanings?
< debug lacp events >
Did not have time to let this run. Is there a document that will guide me in the results once I can let this command run?
In the end I just need hard data pointing to exactly why this is not coming up.
Below is my config...it is the same on both sides:
interface Port-channel 1
no ip address
mtu 9216
switchport
no shutdown
interface TenGigabitEthernet 1/1
no ip address
!
port-channel-protocol LACP
port-channel 1 mode active
interface TenGigabitEthernet 1/2
no ip address
!
port-channel-protocol LACP
port-channel 1 mode active
DELL-Charles R
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3.7K Posts
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June 20th, 2024 20:45
Hello,
There are basic requirements for a port-channel to establish, and usually the cause is one of these:
1) We see the on the local switch there is LACP port-channel 1 with 2 links te1/1 and te1/2.
If te1/1 goes to one provider, and te 1/2 goes to a different provider, the remote end of these links has to also be in a LACP port-channel for both links to come up. This means that there has to be a port-channel that combines 2 links belonging to 2 different providers, and these remote ports have to belong to the same switch on the remote end (or the 2 switches on the remote end have to be in a VPC (or VLT) type of redundancy to appear as one switch). We need to have a 1 switch local – to 1 switch remote side (1:1) for both links to come up.
The most likely cause is that each provider has their own switch and we have a port-channel going from 1 switch (locally) to 2 switches (on the remote end), and the remote end links are not bundled into LACP.
2) The next likely cause would be if both providers have in fact configured LACP and not a static port-channel. Considering the distance, it may be better to use static LAG and not LACP so that there are no heartbeat PDU delays. On dell (channel-group 1 mode on). Or use lacp long-timeout.
3) There are other requirements – the speed of both links should be the same, the switchport mode (either access or trunk) should also be consistent on both sides, copper vs fiber, and other compatibility requirements.