8024f MST + Cisco

Question

Hi

What i am trying to setup

swa (cisco WS-C3560G-24PS)

swb (cisco WS-C3560G-24PS)

swc (8024f)

swd (8042f)

I have stacked swc & swd (as swc).

so my links are

swc 1/0/1 & 1/0/2 stacked linked to swc2/0/1 & 2/0/2 . these are my stacking ports !

swa gi0/16 => swc1/0/24

swb gi0/16 => swc2/0/24

swa has 2 links to swc

cisco bits

swa

spanning-tree mode rapid-pvst
spanning-tree etherchannel guard misconfig
spanning-tree extend system-id
spanning-tree vlan 1,19,201-211 priority 4096

interface GigabitEthernet0/16
description Trunk Link to swc
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 201-208,250
switchport mode trunk
! shutdown

interface Port-channel1
description Inter-Switch Trunk
switchport trunk encapsulation dot1q
switchport mode trunk
bandwidth 2000000
!
interface GigabitEthernet0/1
description Inter-Switch Trunk
switchport trunk encapsulation dot1q
switchport mode trunk
channel-group 1 mode on

interface GigabitEthernet0/24
description Inter-Switch Trunk
switchport trunk encapsulation dot1q
switchport mode trunk
channel-group 1 mode on

swb

spanning-tree mode rapid-pvst
spanning-tree etherchannel guard misconfig
spanning-tree extend system-id

interface GigabitEthernet0/16
description Trunk Link to swd
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 201-208,250
switchport mode trunk
! shutdown

interface Port-channel1
description Inter-Switch Trunk
switchport trunk encapsulation dot1q
switchport mode trunk
bandwidth 2000000
!
interface GigabitEthernet0/1
description Inter-Switch Trunk
switchport trunk encapsulation dot1q
switchport mode trunk
channel-group 1 mode on

interface GigabitEthernet0/24
description Inter-Switch Trunk
switchport trunk encapsulation dot1q
switchport mode trunk
channel-group 1 mode on

on the 8024f

configure
vlan database
vlan 201-208,250
vlan routing 1 1
exit
spanning-tree mode mst

spanning-tree mst configuration
instance 1 add vlan 1
exit
spanning-tree mst configuration
instance 201 add vlan 201
exit
spanning-tree mst configuration
instance 202 add vlan 202
exit
spanning-tree mst configuration
instance 203 add vlan 203
exit
spanning-tree mst configuration
instance 204 add vlan 204
exit
spanning-tree mst configuration
instance 205 add vlan 205
exit
spanning-tree mst configuration
instance 206 add vlan 206
exit

spanning-tree mst configuration
instance 207 add vlan 207
exit
spanning-tree mst configuration
instance 208 add vlan 208
exit
spanning-tree mst configuration
instance 250 add vlan 250
exit
spanning-tree mst configuration
name "swc"
exit

spanning-tree mst configuration
revision 1
exit

interface Te1/0/24
duplex full
description 'swc to swa'
switchport mode trunk
switchport trunk allowed vlan 201-208,250

interface Te2/0/24
duplex full
description 'swd to swb'
switchport mode trunk
switchport trunk allowed vlan 201-208,250
exit

looking on the 8024f i see this on the port. notice it hasn't received any BPDU packets !

swc

show spanning-tree tengigabitethernet 1/0/24

Port Te1/0/24 Enabled                           Ext. Port Cost: 20000
State: Forwarding                                Role: Designated
Port id: 128.24                                  Int. Port Cost: 20000
Port Fast: No                                   Root Protection: No
Designated bridge Priority: 32768                Address: D067.E5AF.1268
Designated port id: 128.24                       Designated path cost: 0
CST Regional Root: 80:00:D0:67:E5:AF:12:68       CST Port Cost: 0
Root Guard..................................... FALSE
Loop Guard..................................... FALSE
TCN Guard...................................... FALSE
Auto Portfast.................................. TRUE
Port Up Time Since Counters Last Cleared....... 0 day 19 hr 12 min 57 sec
BPDU: sent 34588, received 0

show spanning-tree tengigabitethernet 2/0/24

Port Te2/0/24 Enabled                           Ext. Port Cost: 0
State: Disabled                                  Role: Disabled
Port id: 128.48                                  Int. Port Cost: 0
Port Fast: No                                   Root Protection: No
Designated bridge Priority: 32768                Address: D067.E5AF.1268
Designated port id: 128.48                       Designated path cost: 0
CST Regional Root: 80:00:D0:67:E5:AF:12:68       CST Port Cost: 0
Root Guard..................................... FALSE
Loop Guard..................................... FALSE
TCN Guard...................................... FALSE
Auto Portfast.................................. TRUE
Port Up Time Since Counters Last Cleared....... 0 day 18 hr 41 min 36 sec
BPDU: sent 689, received 0

show spanning-tree summary

Spanning Tree Adminmode........... Enabled
Spanning Tree Version............. IEEE 802.1s
BPDU Guard Mode................... Disabled
BPDU Flood Mode................... Disabled

BPDU Filter Mode.................. Disabled
Configuration Name................ swc
Configuration Revision Level...... 1
Configuration Digest Key.......... 0x46511ebde89aab9201e08f03a0f29719
Configuration Format Selector..... 0

when i check there are 2 roots 1 on the dells and 1 on the cisco .. the cisco are working

swa

sh spanning-tree interface g0/16

Vlan                Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
VLAN0201            Desg FWD 4         128.16   P2p
VLAN0202            Desg FWD 4         128.16   P2p
VLAN0203            Desg FWD 4         128.16   P2p
VLAN0204            Desg FWD 4         128.16   P2p
VLAN0205            Desg FWD 4         128.16   P2p
VLAN0207            Desg FWD 4         128.16   P2p
VLAN0208            Desg FWD 4         128.16   P2p
VLAN0250            Desg FWD 4         128.16   P2p

sh spanning-tree interface g0/16 detail

Port 16 (GigabitEthernet0/16) of VLAN0201 is designated forwarding
   Port path cost 4, Port priority 128, Port Identifier 128.16.
   Designated root has priority 4297, address 001e.bde0.ea00
   Designated bridge has priority 4297, address 001e.bde0.ea00
   Designated port id is 128.16, designated path cost 0
   Timers: message age 0, forward delay 0, hold 0
   Number of transitions to forwarding state: 1
   Link type is point-to-point by default
   BPDU: sent 34489, received 4

show spanning-tree bridge

                                                   Hello Max Fwd
Vlan                         Bridge ID              Time Age Dly Protocol
---------------- --------------------------------- ----- --- --- --------
VLAN0001          4097 ( 4096,   1) 001e.bde0.ea00    2    20   15 rstp
VLAN0019          4115 ( 4096, 19) 001e.bde0.ea00    2    20   15 rstp
VLAN0201          4297 ( 4096, 201) 001e.bde0.ea00    2    20   15 rstp
VLAN0202          4298 ( 4096, 202) 001e.bde0.ea00    2    20   15 rstp
VLAN0203          4299 ( 4096, 203) 001e.bde0.ea00    2    20   15 rstp
VLAN0204          4300 ( 4096, 204) 001e.bde0.ea00    2    20   15 rstp
VLAN0205          4301 ( 4096, 205) 001e.bde0.ea00    2    20   15 rstp
VLAN0207          4303 ( 4096, 207) 001e.bde0.ea00    2    20   15 rstp
VLAN0208          4304 ( 4096, 208) 001e.bde0.ea00    2    20   15 rstp
VLAN0209          4305 ( 4096, 209) 001e.bde0.ea00    2    20   15 rstp
VLAN0250         33018 (32768, 250) 001e.bde0.ea00    2    20   15 rstp

I don't have MST setup on the cisco.. This is the first time I am touching mst

I am guessing if I can get BPDU to be seen its going to start to work

I had found a whitepaper before about 8024f and stp, but as is typical i can't find it now !

AlexSYB · Accepted Answer

Okay so finally got it to work. moved everything to mst.

There is a long and complicated reason why not to use mst wit pvst+ (or anything else apart from mst).

it ha to do with convergance and how stp deals with vlans and lag's !

one i had mst install on both end bang just worked

DELL-Willy M · Answer

Here is link to a whitepaper:

www.dell.com/.../pwcnt_MSTP_interoperability.pdf

It is for a 6200 model, but it should be very similar to the 8024 model.

I will have to spend some time looking thru what you have set up and come back with any possible ideas that may be helpful.

AlexSYB · Answer

Close but not the one I had seen before.

Some points

I am not running MST on the cisco !

Also it says in the doc

BPDU: Always transmitted as untagged. The port receives and transmits BPDUs in all three

MSTP states: Discarding, Learning and Forwarding. If MSTP is disabled for the device (manual

forwarding on all ports), BPDUs received are switched.

but in the example they use switchport mode trunk and not switch port mode general .

from memory the general allows untagged frames and mode trunk doesn't allow untagged

so the examples don't match up. Going to try with allowing untagged frames in and see what happens

vt1012 · Answer

Here is a paper that may be of some help. It states to turn on portfast on the Cisco interfaces that are directly connected to the Powerconnect switches (Method 1). However this paper is for the 8100 and not the 8024, but it shouldn't be hard to try it out.

i.dell.com/.../PowerConnect_8100_interoperability_with_Cisco_Catalyst-6500.pdf

AlexSYB · Answer

Hmm

I think in there setup they have a lag between the 2 dells. My 8024f are stacked there is not stp between them, if I set portfast on the cisco's then I will have a loop

I have to do a bit more or a read on the management vlan, but I don't think i will be enabling portfast

Thanks

AlexSYB · Answer

BUMP. still got issues ... :(

DELL-Willy M · Answer

What are the reasons behind why you want or need to use MST in your environment? I see that you have stated that the 8024 switches are stacked as one switch. Then the only other switches that you have mentioned are the Cisco. You have stated that you are not using MST on the Cisco devices. This leaves me with questions on why MST is needed with your physical set up.

Something to make note of when configuring different modes of STP:

User Guidelines

In RSTP mode, the switch would use STP when the neighbor switch is using STP. In MSTP mode, the switch would use RSTP when the neighbor switch is using RSTP and would use STP when the neighbor switch is using STP.

In essence, MSTP supports multiple spanning tree instances on any given link within a network. Each instance may have multiple VLANs assigned to it and each operates separately as its own RSTP spanning tree with benefits of fewer port states, faster aging, additional port roles, edge ports, and 802.1d compatibility. It is an extension to Rapid Spanning Tree Protocol (RSTP) - IEEE standard 802.1w, which supports only a single spanning tree instance on any given link within a network.

If switch A has 2 connections to switch C then you would typically only have 2 instances with multiple VLANs associated. Instead of an instance for each individual VLAN.

MST configuration is discussed on page 720 of the CLI User Guide found here:

support.dell.com/.../cli_ref.zip

I hope this helps,

AlexSYB · Answer

HI

en.community.dell.com/.../download.aspx

These are 2 documents I found previously whilst researching this. Yes currently I have 2 x cisco's (and they are stacked) and I have 2 x 8024f (they are not currently stacked, but they will be, so I presume they are :) )

I will be at some time in the future extending the l2 network and making loops for redundancy.

The attached documents show that dell did some testing with (r)stp and cisco stp and found that it could take 30 sec for convergence with trunk / lag setups... I would rather not have 30 sec outages and MST addresses that and its their recommended best practice I believe

unfortunately they don't go into how to setup mst :)

I think my current plan is to

1) stack the 8024f ... this is going to remove any loops (as long as I setup lag's)

2) migrate both the cisco and the del to mst (reading some manuals along the way)

I had hoped somebody had done this and would be able to point to an example ... but

Networking General

8024f MST + Cisco

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