8 Replies Latest reply on Feb 15, 2013 10:51 AM by levi

    Possible STP issue

    dcorrea Visitor

      Hello guys,

       

      How you doing!?

       

      I'm writing you because I need a help with an issue that I'm very sure that is about STP, I'm attaching you an image that describes my topology, and the explanation is below:

       

      I have two swtiches NV1234 that connects 4 servers in my data center, so today we set up two Traffic Balancers F5's, and them were connected to the switches in the way that is described on the diagram.

       

      So both F5's can have 2 interfaces, the idea was connect the full mesh just like in the diagram, but the problem is that if I left connected the links that are marked in red, my network goes down.

       

      I'm very sure that is because STP, but I want to consult this with you guys. I did a few configuration by setting the priority 0 to the switch that connects to the routers and set the pripority of the second SW to 10 I was thinking that the second switch would put some ports in blocking state but it didn't.

       

      Would you help me here!?

       

      Thanks a millions!

        • Re: Possible STP issue
          Employee

          @dcorrea - Thanks for your question. We would be happy to help you out. We need further information to troubleshoot your issue. Could you provide the current configurations of both 1234s? Please be sure to edit out any information that would be sensitive to your company's network. Also, please specify which switchports on each 1234 are plugging into the following: 1.) load balancers 2.) the other 1234 3.) the internet routers Also, please provide the output to "show span" from both NetVanta 1234s while all connections are plugged in.

           

          Let us know if you have any questions.

           

          Thanks,

          Noor

          • Re: Possible STP issue
            dcorrea Visitor

            Dear Noor,

             

            Thanks for the help on this topic, as you requested here are my both configurations of my switches.

             

            PRIMARY

             

            ip default-gateway 10.10.10.254

            ip name-server 200.57.64.66 200.57.64.67

            !

            !

            no auto-config

            !

            event-history on

            no logging forwarding

            no logging email

            !

            no service password-encryption

            !

            !

            !

            !

            !

            !

            !

            no dot11ap access-point-control

            !

            !

            !

            !

            !

            spanning-tree priority 0

            !

            !

            !

            vlan 1

              name "Default"

            !

            interface switchport 0/1

              no shutdown

            !

            interface switchport 0/2

              no shutdown

            !

            interface switchport 0/3

              no shutdown

            !

            interface switchport 0/4

              no shutdown

            !

            interface switchport 0/5

              no shutdown

            !

            interface switchport 0/6

              no shutdown

            !

            interface switchport 0/7

              no shutdown

            !

            interface switchport 0/8

              no shutdown

            !

            interface switchport 0/9

              no shutdown

            !

            interface switchport 0/10

              no shutdown

            !

            interface switchport 0/11

              no shutdown

            !

            interface switchport 0/12

              no shutdown

            !

            interface switchport 0/13

              no shutdown

            !

            interface switchport 0/14

              no shutdown

            !

            interface switchport 0/15

              no shutdown

            !

            interface switchport 0/16

              no shutdown

            !      

            interface switchport 0/17

              no shutdown

            !

            interface switchport 0/18

              no shutdown

            !

            interface switchport 0/19

              no shutdown

            !

            interface switchport 0/20

              no shutdown

            !

            interface switchport 0/21

              no shutdown

            !

            interface switchport 0/22

              no shutdown

            !

            interface switchport 0/23

              no shutdown

            !

            interface switchport 0/24

              no shutdown

            !

            !

            interface gigabit-switchport 0/1

              no shutdown

            !

            interface gigabit-switchport 0/2

              no shutdown

            !

            interface gigabit-switchport 0/3

              no shutdown

            !

            interface gigabit-switchport 0/4

              no shutdown

              switchport mode trunk

            !

            !

            !

            interface vlan 1

              ip address  10.10.10.251  255.255.255.0

              no shutdown

            !

            !

            !      

            no tftp server

            no tftp server overwrite

            ip http server

            ip http secure-server

            no ip snmp agent

            no ip ftp server

            ip ftp server default-filesystem flash

            no ip scp server

            no ip sntp server

            !

            !

            !

            !

            !

             

             

            !

            !

            ------------------------------------------

            SH SPAN ON MAIN SWITCH

             

            NV1234-LAN-SW#sh span

            STP 0

            Vlan 1

              Spanning Tree enabled protocol ieee 802.1w (Rapid Spanning-Tree)

              Root ID    Priority     0

                         Address      00:a0:c8:77:a3:22

                         The root of the spanning tree

                         Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

             

             

              Bridge ID  Priority     0

                         Address      00:a0:c8:77:a3:22

                         Aging Time   300

             

             

            Interface        Role Sts Cost      Prio.Nbr Type

            ---------------- ---- --- --------- -------- ------------------------------

            swx 0/1          Desg FWD 19         128.1   P2p  

            swx 0/2          Desg FWD 19         128.2   P2p  

            swx 0/3          Desg FWD 19         128.3   P2p  

            swx 0/4          Desg FWD 19         128.4   P2p  

            swx 0/5          Desg FWD 19         128.5   P2p  

            swx 0/7          Desg FWD 19         128.7   P2p  

            swx 0/9          Desg FWD 19         128.9   P2p  

            swx 0/11         Desg FWD 19         128.11  P2p  

            swx 0/13         Desg FWD 19         128.13  P2p  

            swx 0/14         Desg FWD 19         128.14  P2p  

            swx 0/23         Desg FWD 19         128.23  P2p  

            swx 0/24         Desg FWD 19         128.24  P2p  

            giga-swx 0/3     Desg FWD 4          128.27  P2p  

            giga-swx 0/4     Desg FWD 4          128.28  P2p  

             

            SECONDARY SWITCH

             

            !

            ! ADTRAN, Inc. OS version 18.01.04.00

            ! Boot ROM version 17.03.02.SB

            ! Platform: NetVanta 1234, part number 1700594G1

            ! Serial number LBADTN1116AC560

            !

            !

            hostname "NV1234-LAN-SW2"

            enable password password

            !

            clock timezone -6-Mexico-City

            ip default-gateway 10.10.10.254

            ip name-server 200.57.64.66 200.57.64.67

            !

            !

            no auto-config

            !

            event-history on

            no logging forwarding

            no logging email

            !

            no service password-encryption

            !

            !

            !

            !

            !

            !

            !

            no dot11ap access-point-control

            !

            !

            !

            !

            !

            spanning-tree priority 2

            !

            !

            !

            vlan 1

              name "Default"

            !

            interface switchport 0/1

              no shutdown

            !

            interface switchport 0/2

              no shutdown

            !

            interface switchport 0/3

              no shutdown

            !

            interface switchport 0/4

              no shutdown

            !

            interface switchport 0/5

              no shutdown

            !

            interface switchport 0/6

              no shutdown

            !

            interface switchport 0/7

              no shutdown

            !

            interface switchport 0/8

              no shutdown

            !

            interface switchport 0/9

              no shutdown

            !

            interface switchport 0/10

              no shutdown

            !

            interface switchport 0/11

              no shutdown

            !

            interface switchport 0/12

              no shutdown

            !

            interface switchport 0/13

              no shutdown

            !

            interface switchport 0/14

              no shutdown

            !

            interface switchport 0/15

              no shutdown

            !

            interface switchport 0/16

              no shutdown

            !      

            interface switchport 0/17

              no shutdown

            !

            interface switchport 0/18

              no shutdown

            !

            interface switchport 0/19

              no shutdown

            !

            interface switchport 0/20

              no shutdown

            !

            interface switchport 0/21

              no shutdown

            !

            interface switchport 0/22

              no shutdown

            !

            interface switchport 0/23

              no shutdown

            !

            interface switchport 0/24

              no shutdown

            !

            !

            interface gigabit-switchport 0/1

              no shutdown

            !

            interface gigabit-switchport 0/2

              no shutdown

            !

            interface gigabit-switchport 0/3

              no shutdown

            !

            interface gigabit-switchport 0/4

              no shutdown

              switchport mode trunk

            !

            !

            !

            interface vlan 1

              ip address  10.10.10.250  255.255.255.0

              no shutdown

            !

            !

            !      

            no tftp server

            no tftp server overwrite

            ip http server

            ip http secure-server

            ip snmp agent

            no ip ftp server

            ip ftp server default-filesystem flash

            no ip scp server

            no ip sntp server

            !

            !

            !

            !

            !

            snmp-server enable traps

            snmp-server community public RO

            snmp-server community private RW

            snmp-server host 10.10.10.120 traps version 2c public

            !

            !

             

             

            !

            !

            line con 0

              no login

            !

            line telnet 0 4

              login

              password password

              no shutdown

            line ssh 0 4

              login local-userlist

              no shutdown

             

            ----------------

            SECONDARY SWITCH SH SPAN

             

             

            NV1234-LAN-SW2#sh spanning-tree

            STP 0

            Vlan 1

              Spanning Tree enabled protocol ieee 802.1w (Rapid Spanning-Tree)

              Root ID    Priority     0

                         Address      00:a0:c8:77:a3:22

                         Cost         4

                         Port         25 (giga-swx 0/1)

                         Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

             

             

              Bridge ID  Priority     2

                         Address      00:a0:c8:77:9a:fa

                         Aging Time   300

             

             

            Interface        Role Sts Cost      Prio.Nbr Type

            ---------------- ---- --- --------- -------- ------------------------------

            swx 0/1          Desg FWD 19         128.1   P2p  

            swx 0/3          Desg FWD 19         128.3   P2p  

            swx 0/4          Desg FWD 19         128.4   P2p  

            swx 0/5          Desg FWD 19         128.5   P2p  

            swx 0/7          Desg FWD 19         128.7   P2p  

            giga-swx 0/1     Root FWD 4          128.25  P2p 

             

            Now talking about the connections, here is the map:

             

            1) The loadbalancers are connected to each switch on gigabit switchport G0/1 and G0/2

            2)The trunk link of the switches is located on port G0/3

            3)The routers are connected on the main switch (NV1234-LAN-SW) on ports swx0/23 and swx 0/24

             

            Hope this information helps you on this issue.

             

            Thanks a millions!

              • Re: Possible STP issue
                Employee

                @dcorrea - Thank you for providing that information. I noticed a couple of things based on the "show span" outputs you provided from both switches"

                 

                - First, the "show span" output is showing inconsistencies based on how you stated everything is connected:

                • Load balancers are connected to each switch on G0/1 and G0/2.
                  • I am only seeing G0/3 and G0/4 active on the primary 1234
                  • Also, I am only seeing G0/1 active on the secondary 1234
                • Trunk link of the switches is on G0/3
                  • I am seeing that only G0/4 of both the primary and secondary switches are in trunk mode.
                  • Also, as I mentioned above, G0/3 and G0/4 are only active on the primary 1234 and not the secondary 1234

                 

                At the point where you obtained the "show span" output, there were currently no detected loops in your network. Therefore all ports on the primary and secondary 1234 were in a forwarding state. Based on the diagram you sent, the design is a legitimate one, however, we need to see the output of "show span" with all connections active to see what spanning-tree is calculating. We also need to confirm which switchports on both the primary and secondary 1234s are plugging into which equipment. Also, is there a direct link between the Load Balancers in the network?

                 

                Let us know if you have any questions.

                 

                Thanks,

                Noor

                1 of 1 people found this helpful
                  • Re: Possible STP issue
                    dcorrea Visitor

                    Dear Noor,

                     

                    Thanks for the follow up on this, you were right in your assumptions, the situation is that because a failure that we have with the loop, they disconnect the load balancers , and also yes the switches have the trunk on the g0/4.

                     

                    So the point is to try to replicate the scenario that is described on my image, but I need to do this next weekend.

                     

                    So, it is possible for you to give me some suggestions in how configure the switches in order to avoid the loop on the network if i set up the load balancers again!?

                     

                    Thanks in advance,

                      • Re: Possible STP issue
                        Employee

                        @dcorrea - I think you were correct in setting the primary switch with a spanning-tree priority of 0 and the secondary switch with a higher priority. I don't see a reason why the switches wouldn't have been able to detect the loops, so I suspect that the load balancers may be involved in some way. This is part of the reason I would like to see an accurate topology with the ports labeled and the output of "show span" with everything plugged in.

                         

                        Please reply to this post with that information once you have a chance to set it up.

                         

                        Thanks,

                        Noor

                          • Re: Possible STP issue
                            dcorrea Visitor

                            Dear Noor,

                             

                            Thanks for the feedback, I will ask the customer if they F5 balancers can handle the spanning tree and after that maybe this weekend I will work on it.

                             

                            I'll collect the information about connected ports and status of the spanning tree for future troubleshooting.

                             

                            Thanks a bunch!

                            1 of 1 people found this helpful
                              • Re: Possible STP issue
                                Employee

                                @dcorrea - I went ahead and marked this post as "assumed answered".  Feel free to mark any correct or helpful answers from this post.  If you still need assistance with this issue I would be more than happy to help, just let me know in a reply.

                                 

                                Thanks,

                                Noor

                      • Re: Possible STP issue
                        levi Employee

                        dcorrea:

                         

                        I went ahead and flagged the "Correct Answer" on this post to make it more visible and help other members of the community find solutions more easily. If you don't feel like the answer I marked was correct, feel free to come back to this post and unmark it and select another in its place with the applicable buttons.  If you still need assistance, we would be more than happy to continue working with you on this - just let us know in a reply.

                         

                        Thanks,

                         

                        Levi