Regards Re-Designing network ?

Answered Question
Jul 1st, 2008

Hi,

our organisation presently have (2) 1841 Moduler Router and (15) Unmanageble Switches and (1) Cisco 2950 Switch with (250 )PC's.my question's are as follows.

1) can we create 20 subinterface to support 20 vlans on 1841 router (yes/No)

2)can we configure 20 vlan on 2950 switch and connect each vlan port to unmanageble switch so that the unmanageble switch will in one VLAN.(Yes/No)

3)will be ther any issue if i do this type of network design.

Regards

Kiran Kumar CH

I have this problem too.
0 votes
Correct Answer by stephen.stack about 8 years 5 months ago

Yes, thats what it will look like. Bear in mid for an effective network design, you must keep all VLANs in different IP subnets. i.e.

VLAN 10 in 192.168.10.x

vlan 11 in 192.168.11.x

This will ensure that any interval traffice will go thru the router in case of a loop in the network.

Stephen

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (2 ratings)
Loading.
stephen.stack Wed, 07/02/2008 - 00:36

Hi,

To answer your questions inline...

1) can we create 20 subinterface to support -20 vlans on 1841 router (yes/No)

The answer appears to be that the Cisco 1841 can support up to 700 Subs. See here.

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_tech_note09186a0080094322.shtml

2)can we configure 20 vlan on 2950 switch and connect each vlan port to unmanageble switch so that the unmanageble switch will in one VLAN.(Yes/No)

- Quite simply - Yes :)

3)will be ther any issue if i do this type of network design.

-The only thing that comes to mind is if for some reason one or more of the unmanaged switches are connected to each other. i.e. a lin to the catalyst form one switch and a link to one os the other unmanaged switchs. This will cause a loop in the network - causing a broadcast storm, hence bringing your network to it's knees. These switchs will not support the mechanism to stop this form happening.

Other than that, an all round good, simple design.

HTH (Please rate if it does)

Stephen

kirankumar.chamakura Wed, 07/02/2008 - 00:52

Hi Stephen,

you mean to say if we connect the unmanageble switche Vlan 2 connected with unmagable switch of Vlan 3, will create a loop and broadcast strom is that what you mean.a doc has been attached for confirmation please read the Bold sentence.

stephen.stack Wed, 07/02/2008 - 01:03

Ah, No, you won't. (Sorry got a bit ahead of myself there :) )

If each switch is on it's own VLAN you won't create a loop.

Sorry about that. It's early here.

Regards

Stephen

Correct Answer
stephen.stack Wed, 07/02/2008 - 01:19

Yes, thats what it will look like. Bear in mid for an effective network design, you must keep all VLANs in different IP subnets. i.e.

VLAN 10 in 192.168.10.x

vlan 11 in 192.168.11.x

This will ensure that any interval traffice will go thru the router in case of a loop in the network.

Stephen

a.alekseev Wed, 07/02/2008 - 01:18

It would be better if you use L3 switch for routing between VLANs.

For example Catalyst 3560...

kirankumar.chamakura Wed, 07/02/2008 - 01:32

Hi Stephen,

can you help me with price and the best Cisco Layer 3 Device for Smal and Medium size office with 300 Employees.

Regards

Kiran Kumar CH

Actions

This Discussion