From: Church, Chuck (cchurch@netcogov.com)
Date: Sat Feb 04 2006 - 01:17:16 GMT-3
Interesting. Searching around, I found:
http://www.sunmanagers.org/archives/1997/2011.html talk about it a bit.
They called it a keepalive. I'm not sure if that is the normal
keepalive that ethernet interfaces use. Can you issue a 'no keep' on
the switchport, and see if it fixes it?
Chuck Church
Lead Design Engineer
CCIE #8776, MCNE, MCSE
Netco Government Services - Design & Implementation Team
1210 N. Parker Rd.
Greenville, SC 29609
Home office: 864-335-9473
Cell: 864-266-3978
cchurch@netcogov.com
PGP key: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x4371A48D
"I'm one Snickers Pie away from losing my foot to diabetes." - Homer
-----Original Message-----
From: Mike O [mailto:mikeeo@email.msn.com]
Sent: Friday, February 03, 2006 6:55 PM
To: Church, Chuck; ccielab@groupstudy.com
Subject: Re: OT-switch MAC addresses
Chuck,
I have been fooling around with this and used the following settings on
the
port facing the modem
switchport access vlan 85
switchport mode access
switchport nonegotiate
no cdp enable
spanning-tree bpdufilter enable
spanning-tree bpduguard enable
But when I sniff the port with ethereal I get CTP frames:
Configuration Test Protocol (loopback)
Type: Loopback (x9000)
src mac and dest mac are the same and its the mac of the FE port on the
switch. My cable modem picks that mac up and stores it.
Any ideas?
I checked into CTP frames and they are in the Ethernet II spec my I
guess is
cheapy switches don't adhere to it very well but Cisco does?
Thanks,
Mike
----- Original Message -----
From: "Church, Chuck" <cchurch@netcogov.com>
To: "Mike O" <mikeeo@email.msn.com>; "Joseph Eleazar"
<joseph_eleazar@hotmail.com>; <ccielab@groupstudy.com>
Sent: Monday, January 16, 2006 11:04 AM
Subject: RE: OT-switch MAC addresses
> You need to disable all traffic on the 2950 switchport that would have
> it's own MAC address in the frame. So for the port facing the cable
> modem, disable:
>
> Spanning tree
> Any trunk-negotiation frames
> And channel-negotiation frames
> CDP
>
>
> Chuck Church
> Lead Design Engineer
> CCIE #8776, MCNE, MCSE
> Netco Government Services - Design & Implementation
> 1210 N. Parker Rd.
> Greenville, SC 29609
> Home office: 864-335-9473
> Cell: 703-819-3495
> cchurch@netcogov.com
> PGP key: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x4371A48D
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> Mike O
> Sent: Monday, January 16, 2006 9:39 AM
> To: Joseph Eleazar; ccielab@groupstudy.com
> Subject: Re: OT-switch MAC addresses
>
> Joe,
>
> As soon as I plug in the modem, it records the 2950's switchport MAC
> address. If I use a cheapy linksys switch it doesn;t. Is there anyway
to
>
> disable the switchport MAC?
> ----- Original Message -----
> From: "Joseph Eleazar" <joseph_eleazar@hotmail.com>
> To: <mikeeo@email.msn.com>; <ccielab@groupstudy.com>
> Sent: Sunday, January 15, 2006 11:35 PM
> Subject: RE: OT-switch MAC addresses
>
>
>> Mike,
>>
>> Assuming that all ports on the 2950 and 3550 are on the same vlan,
use
>
>> vlan 1 for simplicity, then:
>>
>> 1. Make sure that the interface vlan 1 on both switches are not set
up
> for
>> dhcp.
>> 2. Make sure that the trunk between the switches are passing vlan 1.
>> 3. Make sure that the ethernet port on the 2620 that connects to the
>> switch is configured for dhcp.
>>
>> With that setup and the cable modem connected to the 2950, the the
> 2620 on
>> the 3550 should grab an IP address, that should leave 2 addresses for
> 2
>> more devices that connect to either switch to grab a dhcp address
from
> the
>> cable modem.
>>
>> Joe
>>
>>
>>>From: "Mike O" <mikeeo@email.msn.com>
>>>Reply-To: "Mike O" <mikeeo@email.msn.com>
>>>To: <ccielab@groupstudy.com>
>>>Subject: OT-switch MAC addresses
>>>Date: Sun, 15 Jan 2006 13:20:51 -0500
>>>
>>>My ISP (Comcast) assigns IP addresses per MAC. And my cable modem
> allows 3
>>>MAC addresses to be registered. My problem is I want my 2620 in my
lab
> to
>>>be assigned an address but when I plug the cable modem into my 2950
it
>
>>>picks of the MAC of the switch port and doesn't let the 2620
register.
> Is
>>>there anyway to disable the mac address of the port?
>>>
>>>My 2620 is plugged into my 3550 which is trunked to the 2950 and VLAN
> is
>>>created to carry internet traffic to the cable modem, but like I said
> it
>>>picks up the switchport MAC instead.
>>>
>>>Thanks,
>>>
>>>Mike
>>>
>>>_____________________________________________________________________
_
> _
>>>Subscription information may be found at:
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>
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