Voice over IP Cisco - multiple devices off 7940

Author

multiple devices off 7940

Voll, Scott

2005-07-19, 8:45 pm

Can you have a little 4 port switch hanging off a 7940 phone. I can't seem to get more then one device working off the phone..... Is this a limitation?

Thanks

Scott

Brett Looney

2005-07-19, 8:45 pm

At 07:29 20/07/2005, you wrote:
>Can you have a little 4 port switch hanging off a 7940 phone. I can't
>seem to get more then one device working off the phone..... Is this a
>limitation?

I've had a 3750 hanging off a 7912 before - obviously not trunking or
anything. Works like a charm. Can't speak for the 7940 though - sorry...

B.

Brian Feeny

2005-07-19, 8:45 pm

does it log anything? You sure its not port security or some effect =

shutting down?

On Jul 19, 2005, at 7:29 PM, Voll, Scott wrote:

> Can you have a little 4 port switch hanging off a 7940 phone.=A0 I can't =

> seem to get more then one device working off the phone..... Is this a =

> limitation?
> =A0
> Thanks
> =A0
> Scott___________________________________
____________
> cisco-voip mailing list
> cisco-voip@puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-voip
>
---------------------------------------------
Brian Feeny, CCIE #8036, CISSP
Senior Network Engineer
CTI | Coleman Technologies Inc
561-214-2470

Mike Armstrong

2005-07-20, 7:45 am

A large percentage of our 7940s have small switches and hubs hanging off
them. I think the largest is a 16-port; random brands -- whatever Staples
is selling that day :~). No problems that I've seen. Typical port
configuration on a 3524 is:

interface FastEthernet0/6
switchport trunk encapsulation dot1q
switchport trunk native vlan 101
switchport trunk allowed vlan 1,2,101,1002-1005
switchport mode trunk
switchport voice vlan 2
switchport priority extend cos 0
spanning-tree portfast

Mike Armstrong
UF/IFAS CREC
Lake Alfred, FL

From: "Voll, Scott" <Scott.Voll@wesd.org>
Subject: [cisco-voip] multiple devices off 7940
To: <cisco-voip@puck.nether.net>
Message-ID: < D713462ED535184D830F6F6301753E7EF72A@VIS
HNU.wesd.org>
Content-Type: text/plain; charset="iso-8859-1"

Can you have a little 4 port switch hanging off a 7940 phone. I can't seem
to get more then one device working off the phone..... Is this a limitation?

Thanks

Scott

John Kienzle

2005-07-20, 5:45 pm

We have several unmanaged switches and hubs that have been connected to
the 7940 phone at one time or another with no problems.

Thanks.

_____

From: Voll, Scott [mailto:Scott.Voll@wesd.org]
Sent: Tuesday, July 19, 2005 5:30 PM
To: cisco-voip@puck.nether.net
Subject: [cisco-voip] multiple devices off 7940

Can you have a little 4 port switch hanging off a 7940 phone. I can't
seem to get more then one device working off the phone..... Is this a
limitation?

Thanks

Scott

Voll, Scott

2005-07-20, 5:45 pm

UPDATE:

Hub works Great. It seems to be a problem with the Dell True Mobile
2300 (AP, GW, FW, Switch). Couldn't get it to pass regular network
traffic without using NAT/FW.

Thanks

Scott

________________________________

From: cisco-voip-bounces@puck.nether.net
[mailto:cisco-voip-bounces@puck.nether.net] On Behalf Of Voll, Scott
Sent: Tuesday, July 19, 2005 4:30 PM
To: cisco-voip@puck.nether.net
Subject: [cisco-voip] multiple devices off 7940

Can you have a little 4 port switch hanging off a 7940 phone. I can't
seem to get more then one device working off the phone..... Is this a
limitation?

Thanks

Scott

Mike Armstrong

2005-07-21, 7:45 am

We've got a bunch of those in service behind phones. Trick is to configure
them as a bridge, rather than as an AP, and don't let it act as a DHCP
server. I think (will confirm Monday when my Dell 2300 expert gets back)
that we just plug the phone into one of the 4 switchports, rather than the
uplink port, leaving 3 other ports for other devices. Wireless works as
usual.

Mike Armstrong
UF/IFAS CREC
Lake Alfred, FL

> Date: Wed, 20 Jul 2005 14:11:42 -0700
> From: "Voll, Scott" <Scott.Voll@wesd.org>
> Subject: RE: [cisco-voip] multiple devices off 7940
> To: <cisco-voip@puck.nether.net>
> Message-ID: < D713462ED535184D830F6F6301753E7E0173FA56
@VISHNU.wesd.org>
> Content-Type: text/plain; charset="us-ascii"
>
> UPDATE:
>
>
>
> Hub works Great. It seems to be a problem with the Dell True Mobile
> 2300 (AP, GW, FW, Switch). Couldn't get it to pass regular network
> traffic without using NAT/FW.
>
>
>
> Thanks
>
>
>
> Scott

Voll, Scott

2005-07-21, 5:47 pm

Thanks Mike.... I didn't even think of not using the "internet" Port.
If you can let me know of your config I would love that. I don't have a
Bridge mode but I do have an AP and Gateway mode. I'm guessing I should
have set it as AP mode and turned off the DHCP server and plugged it
into a different port.

I'll try it the next time I'm out at the remote site.

Thanks

Scott

-----Original Message-----
From: Mike Armstrong [mailto:mfa@crec.ifas.ufl.edu]
Sent: Thursday, July 21, 2005 5:06 AM
To: cisco-voip@puck.nether.net; Voll, Scott
Subject: RE: [cisco-voip] multiple devices off 7940

We've got a bunch of those in service behind phones. Trick is to
configure
them as a bridge, rather than as an AP, and don't let it act as a DHCP
server. I think (will confirm Monday when my Dell 2300 expert gets
back)
that we just plug the phone into one of the 4 switchports, rather than
the
uplink port, leaving 3 other ports for other devices. Wireless works as

usual.

Mike Armstrong
UF/IFAS CREC
Lake Alfred, FL

> Date: Wed, 20 Jul 2005 14:11:42 -0700
> From: "Voll, Scott" <Scott.Voll@wesd.org>
> Subject: RE: [cisco-voip] multiple devices off 7940
> To: <cisco-voip@puck.nether.net>
> Message-ID: < D713462ED535184D830F6F6301753E7E0173FA56
@VISHNU.wesd.org>
> Content-Type: text/plain; charset="us-ascii"
>
> UPDATE:
>
>
>
> Hub works Great. It seems to be a problem with the Dell True Mobile
> 2300 (AP, GW, FW, Switch). Couldn't get it to pass regular network
> traffic without using NAT/FW.
>
>
>
> Thanks
>
>
>
> Scott