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Cisco VTP/VLAN issue

aubreystarr
Level 1
Level 1

I finally got the IPSec tunnel working between our office PFSense router  (YEA!) using the same supernet config we had in place before. As part  of a staged migration however, we had plugged the production PFSense  router into the 4507 cabs and moved all of our servers onto those switch  blades to get the increase in bandwidth. That has been working fine and  the only road block was the IPSec tunneling issue. When I tried to cut  over and unplugged the production PFSense router from the switch however  I found I could not route internally on the layer 3 switch. This was  working fine in testing prior to pluging in the PFSense router to those  switches. The issue appears to be a corrupted VTP VLAN database on the  Catalyst 4507s. VTP reports it was  last updated on 8/30/2011 by address IP x.x.132.2, which is the day we  plugged in the PFSense router, and is also the IP address of the PFSense  router. We lost half the VLANs, and VTP does not seem to able to remove  or add new ones.

Has anyone else run into this? Is there a  known issue with PFSense and Cisco VLANs? Does anyone have a sugestion  on how to fix this? Unplugging the PFSense router and rebooting the  switches does not have an effect, but based on the date and IP of the  last update, it seems almost certain that PFSense is the original source of the  issue. There is no VLAN service running on PFSense either, so I don't  understand what or why this happened. How do you fix a corrupt VTP database? If I delete vlan.dat will it get recreated?

Thanks in advance!

Here is the relevant output from Cisco:

show vtp status

VTP Version capable             : 1 to 3

VTP version running             : 2

VTP Domain Name                 : corp

VTP Pruning Mode                : Disabled

VTP Traps Generation            : Disabled

Device ID                       : 0017.5abd.a700

Configuration last modified by

x.x.132.2

at

8-30-11

17:39:31 - (from me... bold IP and date match PFS router and date it was plugged into switch)

Local updater ID is 10.0.132.4 on interface Vl1 (lowest numbered VLAN interface found)

Feature VLAN:

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

VTP Operating Mode                : Server

Maximum VLANs supported locally   : 1005

Number of existing VLANs          : 6

Configuration Revision            : 1

show vlan

VLAN Name                             Status    Ports

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

1     default                          active    Gi1/3, Gi1/4, Gi1/5,  Gi1/6, Gi3/3, Gi3/4, Gi4/2, Gi4/3, Gi4/4, Gi4/5, Gi4/6, Gi4/7

                                                 Gi4/8, Gi4/9, Gi4/10, Gi4/11,  Gi4/12, Gi4/13, Gi4/14, Gi4/15, Gi4/16, Gi4/17, Gi4/18

                                                Gi4/19, Gi4/20, Gi4/21, Gi4/22, Gi4/23, Gi4/24, Gi4/25, Gi4/26, Gi4/27, Gi4/28

                                                Gi4/29, Gi4/30, Gi4/31, Gi4/32, Gi4/33, Gi4/34, Gi4/35, Gi4/36, Gi4/37, Gi4/38

                                                Gi4/39, Gi4/40, Gi4/41, Gi4/42, Gi4/43, Gi4/44, Gi4/45, Gi4/46, Gi4/47, Gi4/48

30   VLAN0030                         active    Gi3/17, Gi3/18, Gi3/19, Gi3/20, Gi3/21, Gi3/22, Gi3/23, Gi3/24, Gi3/25, Gi3/26

                                                Gi3/27, Gi3/28, Gi3/29, Gi3/30, Gi3/31, Gi3/32

1002 fddi-default                     act/unsup

1003 trcrf-default                    act/unsup

1004 fddinet-default                  act/unsup

1005 trbrf-default                    act/unsup

VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1 Trans2

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

1    enet  100001     1500  -      -      -        -    -        0      0  

30   enet  100030     1500  -      -      -        -    -        0      0  

1002 fddi  101002     1500  -      -      -        -    -        0      0  

1003 trcrf 101003     4472  -      -      -        -    -        0      0  

1004 fdnet 101004     1500  -      -      -        ieee -        0      0  

1005 trbrf 101005     4472  -      -      -        ibm  -        0      0  

VLAN AREHops STEHops Backup CRF

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

1003 0       0       off

Remote SPAN VLANs

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

Primary Secondary Type              Ports

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

The  2 missing VLANs are the production VLANs, 10 & 20 respectively, but  routing between existing VLANs also appears to be an issue now. All  VLANs were there prior and routing between them was working fine. Thanks  Again!

1 Accepted Solution

Accepted Solutions

Yes you can. Delete the vlan.dat/reboot and then if you only have around 5 vlans use VTP transparent and manually create the vlans on each switch.

Jon

View solution in original post

12 Replies 12

Jon Marshall
Hall of Fame
Hall of Fame

How many other switches are connected to the 4500 ?

I ask because the easiest and most secure solution is to make your 4500 VTP transparent and simply recreate vlan 10 and vlan 20. VTP transparent does not allow any updates to modify it's own VTP database.

How was the PFSense device connected to the 4500 ie. a trunk link or an access port ?

Jon

We have 2 4507 cabs, both with 2 X 48 port mods. Both linked via 2 X 10gb fiber trunk links (right now using rstp, but I plan to use eatherchannel to get the full 20GB later). One is set to vtp server, the other to vtp client. vtp domain, version2, etc are all identicle on both switches. PFSense was plugged into access ports, I was afraid that truck ports might cause an unforseen issue... like this one :/.

If the PFSense was not connected with a trunk then it cannot send a VTP update.

Could you just clarify whether the PFSense was a trunk port or not ?

Are there any other switches apart from the 4500 switches ?

Jon

Thanks for the replies Jon.

Yes, there are dumb unmanaged 1gb Netgear switches that will go away, but will also require a major recabling of the colo racks... which is the only reason they are still there

I am 100% certain that PFSense is plugged into access ports. I set those and triple checked them myself before plugging in the router ports. Which is why I am puzzled by vpt reporting the last updte from one of the IPs on the PFSense router. Maybe that is mis-reported and the vtp corruption is a coinicdence?

Can I unplug PFSense and then just delete the vlan.dat and reboot the cabs? Then recreate everything from scratch?

Yes you can. Delete the vlan.dat/reboot and then if you only have around 5 vlans use VTP transparent and manually create the vlans on each switch.

Jon

Note: "delete cat4000_flash:vlan.dat" returned a permission denied error. "erase cat4000_flash:" was the command that worked, just so others with similar issues can save some time

Cheers,

Aubrey

With rstp active, I assume that last "none" is correct:

o sh int trunk

Port        Mode             Encapsulation  Status        Native vlan

Te1/1       on               802.1q         trunking      1

Te1/2       on               802.1q         trunking      1

Port        Vlans allowed on trunk

Te1/1       1-4094

Te1/2       1-4094

Port        Vlans allowed and active in management domain

Te1/1       1,30

Te1/2       1,30

Port        Vlans in spanning tree forwarding state and not pruned

Te1/1       1,30

Te1/2       none

Aubrey

Yes, the RSTP output is correct because you are currently running the 2 links separately so STP has to block one link otherwise you have a L2 loop. As you say, using etherchannel would be a better way to go.

The PFSense issue is confusing. Without a trunk link it should not be possible to send a VTP update.

If you only have these 2 4500 switches i would do as i suggested before and use VTP transparent to avoid this sort of thing in the future.

Jon

Thanks Jon,

I will try that this weekend and let know Monday how it went.

Have a great weekend!

Cheers,

Aubrey

Hi Jon,

Thanks for your help! Can you send me a private message, I wanted to communicate with you offline if possible. Thanks!

Cheers,

Aubrey

Aubrey

Sent.

Jon

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