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Simple question on installing a switch into existing network


Got a spare switch which I want to put into the network. Current setup is only VLan 1 and no other vlan.


sjcswextdmz01>sh vtp stat

VTP Version : 2

Configuration Revision : 0

Maximum VLANs supported locally : 1005

Number of existing VLANs : 5

VTP Operating Mode : Server

VTP Domain Name :

VTP Pruning Mode : Disabled

VTP V2 Mode : Disabled

VTP Traps Generation : Disabled

MD5 digest : 0x57 0xCD 0x40 0x65 0x63 0x59 0x47 0xBD

Configuration last modified by at 0-0-00 00:00:00

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

I assume I can just put in the other switch and:

1. do a "wr er"

2. reconfigure in transparent mode

3. setup the trunk btwn both switch

The reason for this is the 3750 is limited to 2 span ports which are currently being used so I need an additional span. My concern is how this may effect the c4k which I no access to as this is manage by another group:


Device ID: sjcencrsw1.engr.local

Entry address(es):

IP address:

Platform: cisco WS-C4506, Capabilities: Router Switch IGMP

Interface: GigabitEthernet1/0/12, Port ID (outgoing port): GigabitEthernet2/17

Holdtime : 123 sec

Version : IOS (tm) Catalyst 4000 L3 Switch Software (cat4000-I9S-M), Version 12.2(20)EW, E

advertisement version: 2

VTP Management Domain: 'ENGR'

Native VLAN: 17

Duplex: full


Re: Simple question on installing a switch into existing network

I assume the setup you have shown is your current one. Where exactly are you going to put this new switch in the setup.


Re: Simple question on installing a switch into existing network

I will attach another 3750 to the current 3750.

New Member

Re: Simple question on installing a switch into existing network

I understand that you have only one switch currently and want to add new one.

If you want to create vlan in addition to vlan0 then you need to create trunk using these commands on 3750

int g1/0/23 (or whatever is interface)

switchport trunk encapsulation dot1q

switchport mode trunk

Same on other switch

For configuring VTP domain

as your first switch is in VTP server mode

I suggest you add second switch to client mode instead of transparent mode

Later after creating VLANs you can add port to these desired VLAN using following command

switchport access VLAN number

Rate if it helps

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