From: ccie2be (ccie2be@nyc.rr.com)
Date: Tue Mar 04 2003 - 19:07:14 GMT-3
Thanks for clearing that up. Jim
----- Original Message -----
From: "boby2kusa" <boby2kusa@hotmail.com>
To: "'ccie2be'" <ccie2be@nyc.rr.com>
Sent: Tuesday, March 04, 2003 2:41 PM
Subject: RE: 3550 & DHCP
> Hello,
>
> I am referring to the "service config" on the 3550 which makes it looks
> for the DHCP. You can disable this with "no service config", it similar
> to the router's autoinstall features. The mac you are looking for
> should be the base mac address since the 3550 uses the interface vlan 1
> for management interface. All the SVI in 3550 uses this base mac
> address.
>
>
>
> -----Original Message-----
> From: ccie2be [mailto:ccie2be@nyc.rr.com]
> Sent: Tuesday, March 04, 2003 10:49 AM
> To: Group Study; boby2kusa
> Subject: Re: 3550 & DHCP
>
>
> Hi,
>
> You are right about DHCP - it can be configured to exclude a single ip
> addr or a range of addresses. It can also be set up such that given a
> particular mac addr, it will assign a particular IP addr.
>
> As far as configuring an interface on the 3550 to be a DHCP client, I'm
> not aware that is possible. If it is, could you tell me how that is
> done.
>
> My understanding from reading the config guide, is that the 3550, if it
> doesn't have a configuration file ie. it's right out of the box, will
> use DHCP when it's first powered on to get an IP addr which will be
> assigned to management interface which by default is in vlan 1- the
> address to which you telnet to configure the box.
>
> I guess I'm confused because the documentation says the 3550 will
> automatically use DHCP if it doesn't have a config file and you're
> telling me that otherwise.
>
> In trying to think this thru, I'm imagining a situation where 3550's are
> being deployed remotely to offices which don't have any IT staff. So,
> to make this process simple and be able to set up the 3550 remotely,
> someone in the network dept. acquires the appropriate mac addr and maps
> it to an IP addr in the DHCP server. When the 3550 is cabled up and
> turned on, it then goes out, using DHCP, and gets it's ip addr. At this
> point, someone can telnet to it and further configure it or if a config
> file has been set up on a TFTP server the 3550 will go out and get it's
> config from there.
>
> The only question is what mac addr is used when the DHCP server is being
> configured. The base mac address might work but what you said also
> makes sense - use the mac addr of the interface thru which the DHCP
> requests are sent.
>
> If I only had a 3550, I could test this, but unfortunately I don't.
> Furthermore, since a cisco router can be configured to be a DHCP server,
> it's not hard for me to imagine seeing something like this on the lab
> exam. So, I want to be 100% sure.
>
> Thanks, Jim
>
>
> ----- Original Message -----
> From: "boby2kusa" <boby2kusa@hotmail.com>
> To: "'ccie2be'" <ccie2be@nyc.rr.com>
> Sent: Tuesday, March 04, 2003 12:47 PM
> Subject: RE: 3550 & DHCP
>
>
> > Hello,
> >
> > First of all, when you configure a switch or a router in the network
> > you have to know which interface will be connected to what segment.
> > With that, you should be able to tell what vlan this sgment will be,
> > the 3550 can be configured where the interface itself is a layer 3
> > port or you might have to configure an SVI or an interface vlan. When
>
> > you configure this interface vlan it uses the base mac address as the
> > other respondent pointed and I also included in this e-mail. So, the
> > answer remains as it depends what kind of interface you are using. I
> > hoe that is finally clear. Besides, I thought that on a DHCP you can
> > exclude ip addresses that you don't want to assign, these includes
> > gateway ip addresses. The 3550 will not automatically seek the DHCP
> > for an IP address, you have to configure the interface first to get
> > it's ip address through DHCP.
> >
> >
> >
> > sw1#sh ver
> > Cisco Internetwork Operating System Software
> > IOS (tm) C3550 Software (C3550-I5K2L2Q3-M), Version 12.1(12c)EA1a,
> > RELEASE SOFTW ARE (fc1)
> > Copyright (c) 1986-2002 by cisco Systems, Inc.
> > Compiled Fri 27-Dec-02 11:06 by antonino
> > Image text-base: 0x00003000, data-base: 0x00855450
> >
> > ROM: Bootstrap program is C3550 boot loader
> >
> > sw1 uptime is 17 hours, 9 minutes
> > System returned to ROM by power-on
> > System image file is
> > "flash:c3550-i5k2l2q3-mz.121-12c.EA1a/c3550-i5k2l2q3-mz.121
> > -12c.EA1a.bin"
> >
> > cisco WS-C3550-24 (PowerPC) processor (revision C0) with 65526K/8192K
> > bytes of m emory.
> > Processor board ID CAT0613Z07D
> > Last reset from warm-reset
> > Bridging software.
> > Running Layer2/3 Switching Image
> >
> > Ethernet-controller 1 has 12 Fast Ethernet/IEEE 802.3 interfaces
> >
> > Ethernet-controller 2 has 12 Fast Ethernet/IEEE 802.3 interfaces
> >
> > Ethernet-controller 3 has 1 Gigabit Ethernet/IEEE 802.3 interface
> >
> > Ethernet-controller 4 has 1 Gigabit Ethernet/IEEE 802.3 interface
> >
> > 24 FastEthernet/IEEE 802.3 interface(s)
> > 2 Gigabit Ethernet/IEEE 802.3 interface(s)
> >
> > The password-recovery mechanism is enabled.
> > 384K bytes of flash-simulated non-volatile configuration memory. Base
> > ethernet MAC Address: 00:09:43:B4:24:00 Motherboard assembly number:
> > 73-5700-08 Power supply part number: 34-0966-02
> > Motherboard serial number: CAT0612062U
> > Power supply serial number: LIT060500CK
> > Model revision number: C0
> > Motherboard revision number: B0
> > Model number: WS-C3550-24-EMI
> > System serial number: CAT0613Z07D
> > Configuration register is 0x10F
> >
> > sw1#sh mac ma
> > sw1#sh mac mac
> > sw1#sh mac ?
> > access-group MAC access-group
> > address-table MAC forwarding table
> >
> > sw1#sh mac add
> > sw1#sh mac address-table
> > Mac Address Table
> > ------------------------------------------
> >
> > Vlan Mac Address Type Ports
> > ---- ----------- ---- -----
> > All 0009.43b4.2400 STATIC CPU
> > All 0009.43b4.2401 STATIC CPU
> > All 0009.43b4.2402 STATIC CPU
> > All 0009.43b4.2403 STATIC CPU
> > All 0009.43b4.2404 STATIC CPU
> > All 0009.43b4.2405 STATIC CPU
> > All 0009.43b4.2406 STATIC CPU
> > All 0009.43b4.2407 STATIC CPU
> > All 0009.43b4.2408 STATIC CPU
> > All 0009.43b4.2409 STATIC CPU
> > All 0009.43b4.240a STATIC CPU
> > All 0009.43b4.240b STATIC CPU
> > All 0009.43b4.240c STATIC CPU
> > All 0009.43b4.240d STATIC CPU
> > All 0009.43b4.240e STATIC CPU
> > All 0009.43b4.240f STATIC CPU
> > All 0009.43b4.2410 STATIC CPU
> > All 0009.43b4.2411 STATIC CPU
> >
> >
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
> > Of ccie2be
> > Sent: Monday, March 03, 2003 5:48 PM
> > To: Group Study; boby2kusa
> > Subject: Re: 3550 & DHCP
> >
> >
> > Hi,
> >
> > Thanks for responding to my question. However, another person wrote
> > that I should just do a "show version" and use that "base" mac
> > address. Is that ever true? Sometimes true? or never true?
> >
> > Also, according to the 3550 config guide, the 3550 switch will
> > automatically generate a DHCP request upon bootup if a config file
> > isn't present. Although it didn't say anything about this, my
> > assumption is that if there isn't any config file, then there's only
> > the default vlan, and all interfaces are in their default state
> > (whatever that is). Is that true? And, if so, what mac address do I
> > use? Is it possible that there's more than 1 mac address that will
> > work for this purpose?
> >
> > Also, suppose you're deploying a new Cat 3550 to a network that is
> > using DHCP but you don't want the 3550 to use DHCP. What do you do
> > then? Do you 1st have to config the 3550 before connecting it do the
> > network?
> >
> > The config guide isn't very clear about the sequence. I'm not sure
> > whether the switch will go into the set up program first or request
> > data from a DHCP server.
> >
> > BTW, please forgive me for all these questions - I don't have a 3550
> > to test these different things.
> >
> > Thanks for your help. Jim
> >
> >
> > ----- Original Message -----
> > From: "boby2kusa" <boby2kusa@hotmail.com>
> > To: "'ccie2be'" <ccie2be@nyc.rr.com>; "'Group Study'"
> > <ccielab@groupstudy.com>
> > Sent: Monday, March 03, 2003 7:51 PM
> > Subject: RE: 3550 & DHCP
> >
> >
> > > It depends, which interface will be getting the ip address through
> > > the
> >
> > > DHCP? If it's the SVI interface then show int vlan #, if it's a
> > > physical interface that is configured to be layer 3 interface then
> > > show int fa #/#. These outputs have layer 2 bia.
> > >
> > >
> > >
> > > -----Original Message-----
> > > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
>
> > > Of ccie2be
> > > Sent: Monday, March 03, 2003 3:06 PM
> > > To: Group Study
> > > Subject: 3550 & DHCP
> > >
> > >
> > > Hi,
> > >
> > > It just occurred to me as I was going thru the 3550 config guide
> > > that since DHCP can be used to assign the 3550's mgmt IP address as
> > > well as
> >
> > > other info, it's necessary to know how to find the 3550's mac
> > > address to set up the DHCP server. So, here's my question, what mac
>
> > > address should be used for this and where can I find it?
> > >
> > > Thanks, Jim
This archive was generated by hypermail 2.1.4 : Sat Apr 05 2003 - 08:51:32 GMT-3