topic Re: Problem with Cisco and Extreme Switch in ExtremeSwitching (EXOS/Switch Engine)

Problem with Cisco and Extreme Switch

rstoccom — Tue, 26 Jan 2021 11:03:59 GMT

Hello everyone!

Hope you all are fine and healthy.

I have been working with the configuration of some Cisco APs connected to a Cisco switch / Switch Extreme for three days. However, so far, no success in this task. As a result, I decided to raise my hand and ask for help. I will leave attached a quite simple (mspaint productions lol) topology here to exemplify my scenario.

The scenario is quite simple too, we need to configure some Cisco APs (model aironet serie 18XX), all of these APs will be connected to Switch Cisco. These APs have a built-in controller, called Mobility Express. In theory, all we need is to configure the first AP / Controller and the rest will be connected automatically during the joining process. So guess what? For some reason, the join just doesn't work.

Some points.
- If the APs are on the same switch. OK, the joining process works without any problems.
- If the APs are connected to another switch (going through Extreme uplink between switchs), the process does not work. Both switchs are reachable, we can ping each other, the gateway, servers, etc.
- We are on the same subnet, so there is not a L3/firewall between.
- Just for testing proposal, If I replace the Extreme with a conventional switch (e.g: tplink), everything works fine, the joining process works with no erros.
- Switch Extreme does not have any special configuration, standard configuration (ports auto neg, speed full, access mode). (Although there are some VLANs configured).
- I have already disabled the flowcontrol, broadcast flooding settings. Unsuccessfully.
- We have already made contact with Cisco, however, Cisco is unable to help due to the connection switch being Extreme.

Everything indicates that for some reason Extreme is blocking this communication during the AP's JOIN process. Maybe broadcast, dtls packets… well, to be honest, I have no more ideas.

Would anyone have any suggestions for solving this puzzle? I really appreciate any help or even an idea.

Thank you all.

Re: Problem with Cisco and Extreme Switch

CWurm — Tue, 26 Jan 2021 15:39:32 GMT

Hi rstoccom,

are you using VLAN 1 (Default) on the Extreme Switch? Extreme has spanning tree enabled by default on VLAN 1 which could possibly interfere with the STP on your Cisco switches.

Also have you tried to connect a clients (PC/notebook/...) to each Cisco switch and ping each other through the Extreme switch to rule out a general connectivity issue between the Ciscos and the Extreme switch?

Kind regards

Christian

Re: Problem with Cisco and Extreme Switch

rstoccom — Tue, 26 Jan 2021 18:16:39 GMT

Hello CWurm.

Yes, we are using default VLAN1. I will check that, maybe disable spaningtree on uplink ports (Extreme).

Yes, connecting a computer on each switch cisco will working just fine

Thank you for you reply.

Re: Problem with Cisco and Extreme Switch

Miguel-Angel_RO — Wed, 27 Jan 2021 06:18:26 GMT

rstoccom,

Just for a test I would disable the igmp snooping on the VLAN 1 on the EXOS switch. APs are often using some kind of multicast to discover neighbors in a legacy way.

Do you use VRRP on the VLAN 1 on the EXOS?

Mig

Re: Problem with Cisco and Extreme Switch

rstoccom — Wed, 27 Jan 2021 06:28:40 GMT

Hello Miguel.

I don't have sure, how can I check it ?

But I guess I’m not using VRRP.

Re: Problem with Cisco and Extreme Switch

rstoccom — Thu, 28 Jan 2021 02:49:12 GMT

@Miguel-Angel RODRIGUEZ-GARCIA

Hello Miguel.

I guess for some reason VRRP multicast is not working.

I’ve captured the packages and the AP detects VRRP and after that, the join process starts.

I don't have VRRP on this Extreme device, no make sense.

Do you have any idea?

Re: Problem with Cisco and Extreme Switch

Miguel-Angel_RO — Thu, 28 Jan 2021 03:02:28 GMT

rstoccom,

As a test, can you disable igmp on the VLAN 1?

With disable igmp snooping vlan 1

Just check if the join succeed

Mig

Re: Problem with Cisco and Extreme Switch

rstoccom — Fri, 29 Jan 2021 03:25:29 GMT

Hello @Miguel-Angel RODRIGUEZ-GARCIA

I’ve tried today - disable igmp snooping vlan 1.

Still no success.

For some reason, the process did not work when the traffic flow through Extreme

Re: Problem with Cisco and Extreme Switch

Miguel-Angel_RO — Fri, 29 Jan 2021 03:57:43 GMT

rstoccom,

Could you share your config on the EXOS?

Mig

Re: Problem with Cisco and Extreme Switch

rstoccom — Fri, 29 Jan 2021 04:30:25 GMT

@Miguel-Angel RODRIGUEZ-GARCIA

Yes, for sure!

I’ve changed some names just for security reasons (vlan name, tags, IP, etc)

All the other “modules” are not set up, it's the default so I don't paste here

#
# Module vlan configuration.
#
configure vlan default delete ports all
configure vr VR-Default delete ports 1:1-34,2:1-34
configure vr VR-Default add ports 1:1-34,2:1-34
configure vlan default delete ports 1:21-22,2:13-17,2:19
configure vlan Default add ports 1:1-20,1:23-34,2:1-12,2:18,2:20-34 untagged

create vlan "DESC_1"
configure vlan DESC_1 tag 100
configure vlan DESC_1 add ports 1:17-20,1:27-28,2:18,2:20,2:27-28 tagged
configure vlan DESC_1 add ports 2:17,2:19 untagged

create vlan "DESC_2"
configure vlan DESC_2 tag 101
configure vlan DESC_2 add ports 2:13-16 untagged

create vlan "DESC_3"
configure vlan DESC_3 tag 102

configure vlan DESC_3 add ports 1:18-20,1:22-24,1:28,2:24,2:28 tagged
configure vlan DESC_3 add ports 1:21 untagged

configure vlan Default ipaddress X.X.X.X Y.Y.Y.Y

#
# Module rtmgr configuration.
#
configure iproute add default GATEWAY_IP

#
# Module edp configuration.
#
enable cdp ports (ALL_PORTS_HERE)

#
# Module ospf configuration.
#
configure ospf vlan Default priority 0

# Module stp configuration.
#
configure stpd s0 mode dot1w
configure stpd s0 add vlan Default ports 1:3-20,1:23-34,2:3-12,2:18,2:20-34 dot1d

Really, thank you so much for helping me.

Re: Problem with Cisco and Extreme Switch

Miguel-Angel_RO — Fri, 29 Jan 2021 05:01:16 GMT

rstoccom,

Everything seem to be good, the config is so basic…

On what ports are connected the cisco switches?

Mig

Re: Problem with Cisco and Extreme Switch

rstoccom — Fri, 29 Jan 2021 05:10:29 GMT

@Miguel-Angel RODRIGUEZ-GARCIA

For now, 1:9 and 1:10.

Yes I said, there is nothing so complicated, It's just the basic. A couple VLANs, stp default, ssh, credentials and motd.

No make any sense

Re: Problem with Cisco and Extreme Switch

Miguel-Angel_RO — Fri, 29 Jan 2021 05:29:06 GMT

Just to be sure,

could you create a brand new vlan and assign the ports 1:9 and 1:10 on it as untagged?

Without IP on it.

How is the AP getting his own IP?

Mig

Re: Problem with Cisco and Extreme Switch

rstoccom — Sat, 30 Jan 2021 04:25:11 GMT

Hello @Miguel-Angel RODRIGUEZ-GARCIA

AP is getting IP address using DHCP service.

We found the problem but not the solution.

Cisco APs use the VRRP protocol to find/elect the Controller AP. Theproblem is Extreme for some reason is not propagate the VRRP multicast.

Simalar case;

Re: Problem with Cisco and Extreme Switch

Miguel-Angel_RO — Sat, 30 Jan 2021 17:02:32 GMT

rstoccom,

I see two steps to try to force it:

disable igmp
remove any ip interface on this VLAN

The goal is to create an L2 bridge that should let anything pass.

Based on the results you’ll be able to provide the info to GTAC…

Mig