Who Here has a 2948g-l3?

calvinj

[H]ard|Gawd
Joined
Mar 2, 2009
Messages
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I'm looking to buy one to have layer 3 switching at home, but am confused with how I go about setting up the routable vlans?

I'm use to cisco 3550, foundry layer 3 routing with the virtual interfaces.

If someone has one and they have done routable vlans can they possible send me a sample config?
 
IIRC that model is not ideal for vlan routing. Btw, why are you looking to do layer 3 services for home use, especially vlan routing?

Your best bet would be to trunk your vlans and use a sub interface on your router (I'm assuming you're going to have this plugged right into your home router), this will get you around vlan routing on the switch and allow the router to take care of it.
 
The 2948-L3 doesn't support SVIs (switched virtual interface) as you're used to with "interface vlan xx".

Instead, you have to use BVIs (bridged virtual interface). SVIs are perfectly normal and accepted practice with today's L3 switches. It's the BVIs that are generally frowned upon.

Code:
int bvi xx
ip addr a.b.c.d

int bvi yy
ip addr a.b.c.d

int bvi zz
ip addr a.b.c.d

int fa0/1
! access port config
no ip addr
bridge-group xx

int fa0/2
! trunk port config
no ip addr

int fa0/2.xx
encap dot xx
bridge-group xx

int fa0/2.yy
encap dot yy
bridge-group yy

int fa0/2.zz
encap dot zz
bridge-group zz

More help:
http://www.cisco.com/en/US/tech/tk389/tk689/technologies_configuration_example09186a00800a875b.shtml
 
I had a feeling that the bridge groups where going to be how i did it. I don't know it should be arriving today I'll let you know
 
IIRC that model is not ideal for vlan routing. Btw, why are you looking to do layer 3 services for home use, especially vlan routing?

Your best bet would be to trunk your vlans and use a sub interface on your router (I'm assuming you're going to have this plugged right into your home router), this will get you around vlan routing on the switch and allow the router to take care of it.

Lots of clients these days that we are doing network installs are going layer 3 routing using switches. It was justified for the practice of setup for these networks. Probably could have gotten a way with a 3550, but we got a deal on this one and it was cheaper than 3550 etc.

I'm starting to think this is going to be a bigger challenge than what I had thought. Oh well I'm up for the challenge
 
The 2948-L3 doesn't support SVIs (switched virtual interface) as you're used to with "interface vlan xx".

Instead, you have to use BVIs (bridged virtual interface). SVIs are perfectly normal and accepted practice with today's L3 switches. It's the BVIs that are generally frowned upon.

Code:
int bvi xx
ip addr a.b.c.d

int bvi yy
ip addr a.b.c.d

int bvi zz
ip addr a.b.c.d

int fa0/1
! access port config
no ip addr
bridge-group xx

int fa0/2
! trunk port config
no ip addr

int fa0/2.xx
encap dot xx
bridge-group xx

int fa0/2.yy
encap dot yy
bridge-group yy

int fa0/2.zz
encap dot zz
bridge-group zz

More help:
http://www.cisco.com/en/US/tech/tk389/tk689/technologies_configuration_example09186a00800a875b.shtml

So what this is saying is anything I need in that vlan needs to be a member of that bridge group or just the sub interfaces?
 
Lots of clients these days that we are doing network installs are going layer 3 routing using switches. It was justified for the practice of setup for these networks. Probably could have gotten a way with a 3550, but we got a deal on this one and it was cheaper than 3550 etc.

I'm starting to think this is going to be a bigger challenge than what I had thought. Oh well I'm up for the challenge

I don't think you will get the right kind of practice with this switch, I've never seen one in production.
 
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