[c-nsp] Fwd: Switches, Loopbacks and VLAN interfaces...

[Gunga Din]

This is correct; loopbacks are for L3 devices; on a 1900/2900, you'll
have to manage those switches inband via an "interface Vlan blah" on
the vlan interface you choose as your "managment" vlan.

Choose wisely on how you set up your inband management vlan topology
btw; I've seen far too many networks that are still doing the
hub-and-spoke "router-on-a-stick" topology that did the old campus
network bit of making vlan 1 the management vlan for every switch,
using a /16 on that interface, and spanning that one vlan around
across every single building in the enterprise.

It doesn't scale well as you grow, and is a pain in the butt to
retrofit.  Not to mention a single issue on that vlan and now every
networking device is unreachable.

On 11/1/06, cigdem gur <cigdem_gur at yahoo.com> wrote:
> Hi,
>
> I agree with Shakeel. Loopback address is available
> for L3 devices. For L2 switches, you should define SVI
> interfaces (interface vlan xx) and give IP addresses
> to this interface.
>
> You can define a management vlan, define this vlan at
> all switches. And then create SVI interfaces on all
> switches and give IP addresses from same IP subnet to
> these SVI interfaces. Also by using "ip default
> gateway" command, you can set 6500 as a default gw.
>
> --- Shakeel Ahmad <shakeelahmad at gmail.com> wrote:
>
> > i believe you can use Loopback addresses in L3
> > switches only - and 2950 is a
> > L2 switch. If someone can correct me if wrong ?
> >
> > SA
> >
> >
> > On 10/31/06, Mark Tohill <Mark at u.tv> wrote:
> > >
> > > Hi,
> > >
> > > I am configuring a series of access switches (from
> > 19/2900XL to
> > > 2950/70's, all running IOS) to live within one
> > management subnet which
> > > will terminate on aggregate 6500's as L3 SVI (via
> > 802.1q trunking). Not
> > > all of these switches give me the ability to
> > configure /32 Loopback
> > > interfaces, only VLAN interfaces which don't like
> > /32 masks.
> > >
> > > Is there any way around this or do I have to
> > provide a mask for the
> > > contiguous /32 loopback block?
> > >
> > > Thanks,
> > > Mark
> > >
> > >
> > >
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