Cannot manage one switch via network

[wn1kbates]

I have three 4506 switches with vlan 4 set as the management vlan. Switch 1 is connected to switch 2 and switch 3.

I can access switch 1 and 2 using telnet from the management vlan and both switches reply to pings. But from switch 1 or 2 I cannot ping or telnet switch 3. If I plug into switch 3 and I can ping and telnet switch 3 but not switches 1 or 2.

It is as if the management vlan 4 is not being passed to/from switch 1 and 3. The configs for the uplinks from switch 1 to 2 and 3 are the same. And the configs for switches 2 and 3 look the same apart from the port settings.

I have over 40 vlans running all that work fine between all the switches.

any ideas??

[NickNac79]

Hi Kevin,

2 things to look at initially...

1) Do a "show vlan id 4" on each switch and check to ensure that the vlan is showing up on all your trunk ports.

2) Go onto each of the 4 switches, and do a "show span vlan 4" and compare the outputs?

They should all report the same Root Bridge, and if  they don't then there's something wrong with your spanning tree config.   There may even be a switching loop somewhere, which you will need to  track down.

Nick

[JohnTylerPearce]

Do a 'show int trunk' on Swtich 3 and make sure the vlan is accepted on the trunk. Also what NicNac suggested, make sure that the vlan is actually on Switch 3. If these are L2 switches only, then you might have to include the 'ip default-gateway x.x.x.x' command in order for you to access this beyond the management vlan if that's something you want to do. But if your goal is just to access from the management vlan then you shouldn't have to worry about doing that, since you will basically be arping for the ip address on the L2 switch anyway.

[wn1kbates]

Thanks I will get someone to site in the morning to get the results from all the switches - Kevin

[wn1kbates]

Below are the results. I'm guess it does not work because vlan 4 is missing from the spanning tree on switch 3

Port Vlans in spanning tree forwarding state and not pruned

Po10 8-11,16,19-110,210-279,300-400,410-465

*************************************** SWITCH 1

4507_Dare_01>sh int trunk
Port        Mode             Encapsulation  Status        Native vlan
Gi4/6       on               802.1q         trunking      1
Po10        on               802.1q         trunking      1
Po20        on               802.1q         trunking      1

Port        Vlans allowed on trunk
Gi4/6       1-500
Po10        1-500
Po20        1-500

Port        Vlans allowed and active in management domain
Gi4/6       1-110,123,210-279,300-400,410-465
Po10        1-110,123,210-279,300-400,410-465
Po20        1-110,123,210-279,300-400,410-465

Port        Vlans in spanning tree forwarding state and not pruned
Gi4/6       1-110,123,210-279,300-400,410-465
Po10        1-110,123,210-279,300-400,410-465
Po20        1-110,123,210-279,300-400,410-465

4507_Dare_01>sh vlan id 4
VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
4    VLAN0004                         active    Gi3/7, Gi3/46, Gi4/6, Gi5/47
                                                Po10, Po20

VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
4    enet  100004     1500  -      -      -        -    -        0      0

Remote SPAN VLAN
----------------
Disabled

Primary Secondary Type              Ports
------- --------- ----------------- ------------------------------------------

4507_Dare_01>sh span vlan 4

VLAN0004
  Spanning tree enabled protocol ieee
  Root ID    Priority    24580
             Address     001a.a1d6.4580
             This bridge is the root
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    24580  (priority 24576 sys-id-ext 4)
             Address     001a.a1d6.4580
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Gi3/7            Desg FWD 4         128.135  P2p Edge
Gi3/46           Desg FWD 19        128.174  P2p
Gi4/6            Desg FWD 4         128.198  P2p
Gi5/47           Desg FWD 4         128.303  P2p Edge
Po10             Desg FWD 3         128.650  P2p
Po20             Desg FWD 3         128.660  P2p

*************************************** SWITCH 2

4507_Dare_02>sh int trunk
Port        Mode             Encapsulation  Status        Native vlan
Po10        on               802.1q         trunking      1

Port        Vlans allowed on trunk
Po10        1-500

Port        Vlans allowed and active in management domain
Po10        1-110,210-279,300-400,410-465

Port        Vlans in spanning tree forwarding state and not pruned
Po10        1-110,210-279,300-400,410-465

4507_Dare_02>sh vlan id 4

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
4    VLAN0004                         active    Po10

VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
4    enet  100004     1500  -      -      -        -    -        0      0

Remote SPAN VLAN
----------------
Disabled

Primary Secondary Type              Ports
------- --------- ----------------- ------------------------------------------

4507_Dare_02>sh span vlan 4

VLAN0004
  Spanning tree enabled protocol ieee
  Root ID    Priority    24580
             Address     001a.a1d6.4580
             Cost        3
             Port        650 (Port-channel10)
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32772  (priority 32768 sys-id-ext 4)
             Address     001a.a18b.ce40
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po10             Root FWD 3         128.650  P2p

*************************************** SWITCH 3
4507_Dare_03#sh int trunk

Port        Mode             Encapsulation  Status        Native vlan
Po10        on               802.1q         trunking      1

Port        Vlans allowed on trunk
Po10        1-500

Port        Vlans allowed and active in management domain
Po10        1-110,210-279,300-400,410-465

Port        Vlans in spanning tree forwarding state and not pruned
Po10        8-11,16,19-110,210-279,300-400,410-465

4507_Dare_03#sh vlan id 4
VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
4    VLAN0004                         active    Gi6/1, Po10

VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
4    enet  100004     1500  -      -      -        -    -        0      0

Remote SPAN VLAN
----------------
Disabled

Primary Secondary Type              Ports
------- --------- ----------------- ------------------------------------------

4507_Dare_03#sh span vlan 4
VLAN0004
  Spanning tree enabled protocol ieee
  Root ID    Priority    24580
             Address     001a.a1d6.4580
             Cost        3
             Port        650 (Port-channel10)
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32772  (priority 32768 sys-id-ext 4)
             Address     001a.a1d6.45c0
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po10             Root FWD 3         128.650  P2p

[JohnTylerPearce]

Port        Vlans in spanning tree forwarding state and not pruned
Po10        8-11,16,19-110,210-279,300-400,410-465

This is under Switch 3, it appears that vlan4 is not allowed across the trunk. It looks like

you need to manually map it.

[wn1kbates]

The running config for the truck is below which I guess shows that all vlans 1-500 are allowed over the trunk ?

interface Port-channel10

description Etherchannel Link to Comms Room Floor4507 ports 1/1 & 2/1

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1-500

switchport mode trunk

!

interface GigabitEthernet1/1

description Link to Comms Room port 1/1

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1-500

switchport mode trunk

channel-group 10 mode desirable

!

interface GigabitEthernet1/2

shutdown

!

interface GigabitEthernet2/1

description Link to Comms Room port 2/1

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1-500

switchport mode trunk

channel-group 10 mode desirable

!

interface Port-channel10

description Etherchannel Link to Comms Room Floor4507 ports 1/1 & 2/1

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1-500

switchport mode trunk

!

interface GigabitEthernet1/1

description Link to Comms Room port 1/1

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1-500

switchport mode trunk

channel-group 10 mode desirable

!

interface GigabitEthernet1/2

shutdown

!

interface GigabitEthernet2/1

description Link to Comms Room port 2/1

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1-500

switchport mode trunk

channel-group 10 mode desirable

!

[JohnTylerPearce]

Are you running VTP by any chance? It looks like vlan 4 is being pruned.

[NickNac79]

Yep, you've got it...

Switch off VLAN pruning on switch 3 to test.

[wn1kbates]

Thanks, I'll check monday morning, I've checked switch 1 and 2 and pruning is off. Have a good weekend.

[jimmysands73_2]

To make the issue easier, can you post/attach the config of the switches?

[wn1kbates]

I've checked the switch and pruning is switched off ?

[Leo Laohoo]

Sounds like the management interface of Switch 3 has the wrong subnet mask.

[glen.grant]

  Does switch 3 have a default gateway defined for vlan 4 or a default static route for vlan 4 if you have ip routing turned on for switch 3 ?  Who is doing the routing for vlan 4 , the mgt vlan ?

[JohnTylerPearce]

From looking at the following it doesn't appear that vlan 4 is allowed on the trunk link from Switch 3 to Switch 1.

Port          Vlans in spanning tree forwarding state and not prund

po10         8-11,16,19-110,210-279,300-400,410,465