Symptoms:

• Setup of XRN
• XRN Configuration Steps

Facts:

• SuperStack 3 Switch 4900
• SuperStack 3 Switch 4924
• SuperStack 3 Switch 4950
• SuperStack 3 Switch 4900 12-Port
• SuperStack 3 Switch 4900 12-Port 1000BASE-SX
• XRN Interconnect Module
• XRN Interconnect Cable
• Switch 4060
• Switch 4050

Causes: Version 3.0 or higher is required on the XRN Core. Check the website 3Com.com for the current release available for your switches. Some edge device support LACP. If using a SuperStack III (SSIII) 4400 - v3.0 or higher. If using SSIII 42xx rev 2.02 and later support LACP. On the SSIII 42xx only the 2 10/100/100BASE-T and GBIC ethernet ports (if available) support aggregated links. At least one edge device must have LACP enabled- see #5 below. Not all edge devices have to have LACP enabled- but they can if you choose too. You cannot have all edge devices using manual aggregated links. At least one edge device must have LACP enabled on an aggregated link.

XRN Cores are limited to 30 vlans and 13 Aggregated Links per core (2 devices connected together via XRN modules/cable)

Fixes: Create Network Diagram (include vlans, port #, ip interfaces)

1) Install Modules

• Units must be powered down to install modules- optional modules are NOT hot swappable.
• If status of module is not solid, or warning appears module not installed - Reseat module or try the module in a different device.

2) XRN cable -lowest mac address does not matter.

• Blue is always master
• Yellow is always slave

3) NOTE: Ethernet port numbering on a 4050/ 4060 - GBIC's are ports 1-6

4) Setup must be configured in the following order for each device

• a. Bridge vlan create
• b. Bridge vlan modify addport
• c. Create ip interfaces
• d. Enable LACP where desired. Configure the rest of the switches
• f. Double check configurations
• g. Now, cable up the switches correctly
• h. Create a network diagram if not already done

lt;o:p>

FYI- if testing recovery by removing cables to trigger a recovery- if the recovery takes more then 5-10 seconds something is not cabled or configured correctly. One of the longest recovery times is when the XRN cable is removed.

5) LACP must be enabled on an edge device in order for a failure of the interconnect cable to recover.

6) Unable to delete/modify the vlan if LACP is enabled - port is still being used by LACP - must disable LACP before deleting/modify vlan

• a. However, the AL partner ID may still be associated with an edge device that doesn't exist, a reboot/hardware reset does not clear this - must initialize the switch to remove.

7) Every vlan must be configured on the uplink ports for lacp - even if the vlan does not exist on the edge device

VID 2 unit 1 pt 1, unit 2 pt 1,  VID 3  unit 1 pt 1, unit 2 pt 1                      associated w/AL1

VID 2 unit 1 pt 2, unit 2 pt 2,  VID 3  unit 1 pt 2, unit 2 pt 2                      associated w/AL2

If switch gets reset traffic will still pass to edge devices on all vids.

bad example:

 vid 2      unit 1 port 1, unit 2 port 1            associated w/AL1

 vid 3      unit 1 port 2, unit 2 port 2            associated w/AL2

If after power cycle AL1 becomes associated w/vid 3 - communication will stop between edge devices using vid 2

8) Always use RSTP on core and edge devices where available

9) To verify which switch is in L2 mode - pr ip inter summary - interfaces that are down are in L2

Commands to check

Bridge vlan detail

Bridge port detail

Bridge linkaggregtion detail

Protocol ip interface summary  
 
 

* Product(s): SuperStack 3 Switches, Switch 4050, Switch 4060 Sub Product(s): SuperStack 3 Switch 4200, SuperStack 3 Switch 4400, SuperStack 3 Switch 4900, SuperStack 3 Switch 4924, SuperStack 3 Switch 4950

— David Gonzalez 2021/04/14 12:05