If I Configure nothing on a switch interface

dppagc

and only unshut it. Does it mean it is on vlan 1?

If I connect to routers together and unshut the interface with no configuration, is it also vlan 1?

bharvey92

On a switch all ports are in VLAN 1 by default.

theodoxa

dppagc wrote: »

and only unshut it. Does it mean it is on vlan 1?

If I connect to routers together and unshut the interface with no configuration, is it also vlan 1?

A router port is typically Layer 3 (excepting for routers with built-in switches). It has no VLAN by default. As for switches, ports are assigned to VLAN 1 by default. When connected to a router, the ports will become access ports by default since router ports don't establish trunk by default. Depending on the model of switch, connecting two switches may result in a trunk or an access port. Also, if I remember correctly switch ports are no shut by default allowing you to plug and go (if you don't mind everyone being in VLAN 1), while routers have all their ports shutdown when shipped.

satishtech

3560L3switch(config)#int f0/1
3560L3switch(config-if)#shut

%LINK-5-CHANGED: Interface FastEthernet0/1, changed state to administratively down

3560L3switch#show vlan brief

VLAN Name Status Ports
----

---

---

---

1 default active Fa0/1,
Fa0/2, Fa0/3, Fa0/4
Fa0/5, Fa0/6, Fa0/7, Fa0/8
Fa0/9, Fa0/10, Fa0/11, Fa0/12
Fa0/13, Fa0/14, Fa0/15, Fa0/16
Fa0/17, Fa0/18, Fa0/19, Fa0/20
Fa0/21, Fa0/22, Fa0/23, Fa0/24
Gig0/1, Gig0/2

1002 fddi-default active
1003 token-ring-default active
1004 fddinet-default active
1005 trnet-default active

crplhood

Switches will make CAM entries, filter, and forward, all on VLAN1, right out of the box. An unconfigured switch just acts like an unmanaged switch, unless an administrator or information-sharing protocol changes something.

If you connect two routers together and no shutdown without any config, nothing will happen. The routers have no idea what exists on the outside of that interface, and have no idea what network that interface belongs in without an interface IP address and netmask.