ip routing statement question

[skiff811]

Background: I recently had a consultated come in and install 3 cisco 3560 PoE switches. We have two wiring closet at opposite ends of the building. The main Closet has 2 3560 PoE cisco switches. The other closet had 1 3560 PoE install. The switches are connected by Fiber in the Gigabit fastethernet ports.

I am in the proccess of adding a second switch to the second closet with one.

While going through the configs i noticed that the 2 switches in the main closet have

!
no aaa new-model
clock timezone PST -8
clock summer-time PDT recurring
ip subnet-zero
ip routing
!
!
!

while the switch in the fat closet config looks like

!
no aaa new-model
clock timezone PST -8
clock summer-time PDT recurring
ip subnet-zero
!
!
!

it is missing the ip routing statement.

Is this important? Also some users have expericened netowrk connections being dropped for a few second every other day. Would this be the cause of the network problems?

 

[vipergg]

It depends on how it was setup , the 3560's up above could actually be doing the routing while the other 3560's were just setup as layer switches in which case you would only see a "ip default-gateway" statement . Hard to say without actually knowing the network setup and config .

 

[chieftan]

The "IP ROUTING" command has to be used to enable layer 3 operation on the device. The two switches with this turned on are performing some form of routing (Maybe between VLANS) and the single switch is only layer 2 enabled.

Need to see the configs.

 

[KiscoKid]

Did this consultant generate a design or proposal document for you? This important document should quickly highlight the roles of individual bits of kit in your network.

The sole 3560 sounds as if it is intended to provide user aggregation, i.e. access layer connectivity.

You really need to review this document, if it exists, to understand the roles of each device in your network. Any decent contractor should produce documentation of this nature for any job they work on (I would anyway).

 

[skiff811]

OK so looking over the documentation

Each wiring closet is suppose to have 1 layer3 switch with HSRP and 1 layer2 switch.

Wiring closet #1 looks like it has 2 layer3 switches. Wiring Closet #2 looks like it has no layer3 switches.

Is the IP routing command the only way to tell if it is a layer3 switch?

what other part of the config do i need to post to allow you to have a better idea?

 

[skiff811]

BTW... i do have the "IP default-gateway" statement in the single switch in wiring closet #2

 

[chieftan]

See the Cisco sight to see what type of switches are Layer 3. You need to set the IP ROUTING command on the 3560 to enable layer 3 or it will just behave like a layer 2 device.

In other words, you can enter as much routing info as you want, but if you do not have the IP ROUTING command enabled then the routing won't work.

Post complete configs

 

[skiff811]

I guess my next question is.

What do I loose or gain from having all of my switches run as layer3?

Say I was to upgrade the 2 layer2 switches to have the IP Routing statement in them. Do I loose anything from doing this?

(all switches are cisco Cat 3560 48 port PoE switches)

 

[chieftan]

You dont lose anything.

You would need to configure other routing information for anything to happen (ie...set the ports with IP addresses, turn on OSPF ...etc,etc).