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mikey250

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3550 VTP/TRUNK ISSUE

Hi ive attached my basic config for my 3550 and just had a few questions which ive also highlighted with questions marks inside notepad file - (?????).

My 3550 is currently attached to my 'Access' Layer 2 switch as just setting up!

can anyone help?

thanks

mike
distribution-L3---3550-switch.TXT
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vtp pruning
Administrative Mode: dynamic desirable: this mode described here

These links would like to become trunk links and will send DTP signals that attempt to initiate a trunk. They will only become trunk links if the other side responds to the DTP signal. This will form a trunk with other ports in the states

Operational Mode: trunk

This could be access or trunk

As for the other question as to why port 20 is not in forwarding I would hazard a guess this is due to spanning tree, perhaps you are connecting this to the same switch as port 19 and 19 being a lower numbered port would be chosen by spanning-tree over 20.  I would do a show span-tree to see what that can tell you.

and the last question you could set it to switch port to access, it will become access either way as the mode dynamic desirable will try to be come a trunk but if it doesn't receive a response will still become an access port.

To speed it up I usually use spanning-tree portfast on access ports.  This prevents any attempt at becoming a trunk and allows the switch to move to forwarding as you are basically promising that there will be no trunk port here so no switching loops will occur so the spanning tree checks will be skipped.
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Hi experts thanks for the extra advice as it is useful and as for the reason of using vlan 99 it is only because ive completed my ccnp but not completed exams yet and as i decided to buy from ebay my own equipment now.  im just following my labs so this is the reason behind using it ensuring it is hardcoded into my memory as i know that the default Native vlan 1 being changed to 99 stops vlan hopping!!

hi NetFixr-Dani,  im currently using a Distribution Layer 3  3550 & an Access Layer 2 24 port cisco 2950 switch to simulate classroom although in the classroom they did use the same L3 3550 & a L2 2960 switch.

I am also using 2 pc's for practical hands which are plugged into fa0/1 of each of my L2 & L3 switches as stated.

As for ports fa0/19 -20, im using x-over cables plugged from Access to Distribution and not into same switch.  Although on my 3550 all  unused ports are set to dynamic except for my connected pc as im using hyperterminal for the time being.

As for my Access layer 2 2950 24 port im using the same default settings for all other ports which SHOULD be as i deleted vlan.dat and erased startup and started my labs as an out of box switch.

So this was why I was wondering why fa0/20 wasnt not showing vlan 1, 30,40 like fa0/19!!!?

One of the other experts mentioned about spanning-tree reacting a certain hence fa0/20 not showing my vlans, but I doubt it!!?

Im  sure when i was on my ccnp course, fa0/20 did show vlans 1,30 40, so just wanted to clear this matter up before I continue!!?
the vlans HAVE been created in fa0/20 as Ive done a 'sh run' to confirm identical config to fa0/19!!
as i go through my labs i will have to setup FEC - FastEtherchannel/Port channelling, hence buying my 3550, so can also run routing also.
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I wasn't specifically addressing the config. Simply pointing out a conceptual issue.
Hi I do realise what the following is:

Access - for host pcs/server etc
Trunk - for connecting switches or routers together specifically
Nonegotiate - doesnt send or respond to DTP
Dynamic Desirable - Sends & Responds to DTP
Dynamic Auto - Only Responds to DTP

but when following my labs as it is stage by stage IM SURE that fa0/20 still showed vlans 1, 30,40.

Yes both Layer 2 & 3 are set currently to 'Transparent' and as I go through my labs I will change L3 to be the Server/Pruning enabled, but not yet & L2 to Client, but no yet.

L3 switch:

sh spanning-tree blocked

Name                 Blocked Interfaces List
-------------------- ------------------------------------
VLAN0001             Fa0/20
VLAN0030             Fa0/20
VLAN0040             Fa0/20

Number of blocked ports (segments) in the system : 3

DSW3#sh spanning-tree int fa0/19

Vlan             Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
VLAN0001         Root FWD 19        128.19   P2p
VLAN0030         Root FWD 19        128.19   P2p
VLAN0040         Root FWD 19        128.19   P2p

DSW3#sh spanning-tree int fa0/20

Vlan             Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
VLAN0001         Altn BLK 19        128.20   P2p
VLAN0030         Altn BLK 19        128.20   P2p
VLAN0040         Altn BLK 19        128.20   P2p
DSW3#

L2 Switch:

sh spanning-tree blocked

Name                 Blocked Interfaces List
-------------------- ------------------------------------

Number of blocked ports (segments) in the system : 0

ASW4#sh spanning-tree int fa0/19

Vlan             Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
VLAN0001         Desg FWD 19        128.19   P2p
VLAN0030         Desg FWD 19        128.19   P2p
VLAN0040         Desg FWD 19        128.19   P2p

ASW4#sh spanning-tree int fa0/20

Vlan             Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
VLAN0001         Desg FWD 19        128.20   P2p
VLAN0030         Desg FWD 19        128.20   P2p
VLAN0040         Desg FWD 19        128.20   P2p
ASW4#

So it seems that I was wrong as  the Distribution switch fa0/19 is the 'ROOT' - the other end attached to L2 fa0/19 - is Desg/Fwd - obviously!

Distribution switch fa0/20 - is the Alternate backup port - & the end attached to L2 fa0/20 - is Desg/Fwd - wouldnt this be in blocking mode?
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Yes your right!!  when I saw 'root' as per previous thread im thinking it is the 'root bridge' but its not, as in fact it is a 'root port' which are situated on L3 switch pointing towards the 'Designated ports' of asw4 - L2 switch being the 'root bridge'  I need to hardcode this into my head!!

so this would be the reason for fa0/20 not showing any vlans currently!

asw4 - L2 - Both Mac addresses on asw4 are identical so this is the root in this case

asw#sh span

VLAN0001
  Spanning tree enabled protocol ieee
  Root ID    Priority    32769
             Address     0014.69ca.2d00
             This bridge is the root - !!!
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32769  (priority 32768 sys-id-ext 1)
             Address     0014.69ca.2d00
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Fa0/1            Desg FWD 19        128.1    P2p
Fa0/19           Desg FWD 19        128.19   P2p
Fa0/20           Desg FWD 19        128.20   P2p


VLAN0030
  Spanning tree enabled protocol ieee
  Root ID    Priority    32798
             Address     0014.69ca.2d00
             This bridge is the root - !!!
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32798  (priority 32768 sys-id-ext 30)
             Address     0014.69ca.2d00
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Fa0/19           Desg FWD 19        128.19   P2p
Fa0/20           Desg FWD 19        128.20   P2p


VLAN0040
  Spanning tree enabled protocol ieee
  Root ID    Priority    32808
             Address     0014.69ca.2d00
             This bridge is the root - !!!
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32808  (priority 32768 sys-id-ext 40)
             Address     0014.69ca.2d00
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Fa0/19           Desg FWD 19        128.19   P2p
Fa0/20           Desg FWD 19        128.20   P2p

ASW4#



DSW L3 switch

DSW3#sh span


VLAN0001
  Spanning tree enabled protocol ieee
  Root ID    Priority    32769
             Address     0014.69ca.2d00
             Cost        19
             Port        19 (FastEthernet0/19)
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32769  (priority 32768 sys-id-ext 1)
             Address     0015.63e0.8f80
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Fa0/1            Desg FWD 19        128.1    P2p
Fa0/19           Root FWD 19        128.19   P2p
Fa0/20           Altn BLK 19        128.20   P2p


VLAN0030
  Spanning tree enabled protocol ieee
  Root ID    Priority    32798
             Address     0014.69ca.2d00
             Cost        19
             Port        19 (FastEthernet0/19)
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32798  (priority 32768 sys-id-ext 30)
             Address     0015.63e0.8f80
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Fa0/19           Root FWD 19        128.19   P2p
Fa0/20           Altn BLK 19        128.20   P2p


VLAN0040
  Spanning tree enabled protocol ieee
  Root ID    Priority    32808
             Address     0014.69ca.2d00
             Cost        19
             Port        19 (FastEthernet0/19)
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32808  (priority 32768 sys-id-ext 40)
             Address     0015.63e0.8f80
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Fa0/19           Root FWD 19        128.19   P2p
Fa0/20           Altn BLK 19        128.20   P2p

DSW3#


so this would be the reason for fa0/20 not showing any vlans currently!

Yes.

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perfect, thanks for the help!!!