[Q]Best doc/link for DHCP services on Cisco

Could anybody point me to a detailed documentation on the workings of DHCP
services in Cisco products (specifically for the 6500 family). Problems I
am trying to address (perhaps some kind soul may already have answers?!?):
- I am trying to pull the information about the various VLANs-assiggned IP
addresses, vs. MACs of end points, through SNMP - and can't find the dam'
OIDs.
- I am trying to run a script (TCL-expect-based) to pull additional info
from the DHCP information, but could not find a way to show onlyh specifis
VLANs (the show ip dhcp binding gets me everything, and I am forced to
take this info "out", and process it via awk) - I would like to have a
sppecific port ALWAYS getting the same IP address, no matter what device
gets plugged in (so it is NOT a MAC-to-port type of associatian, as the
MAC changes continuously, but rather an IP-from-DHCP-to-port restriction)
.... I wonder if this is even possible?!?

TIA,
Papi

 

Hi Papi,

You may wish to investigate Cisco's Understanding and Troubleshooting
DHCP in Catalyst Switch or Enterprise Networks:

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a00800f0804.shtml

Hope this helps.

Sincerely,

Brad Reese
BradReese.Com Cisco Repair Worldwide
United Kingdom: 44-20-70784294
U.S. Toll Free: 877-549-2680
International: 828-277-7272
Fax: 775-254-3558
Website: http://www.bradreese.com/cisco-big-iron-repair.htm

 

Astonishingly there does seem to be a solution for this but it may be
costly.

http://www.cisco.com/en/US/products/sw/netmgtsw/ps1982/products_white_paper0900aecd801edf27.shtml

"INDUSTRIAL ETHERNET SOLUTION WITH CISCO CNS NETWORK REGISTRAR"

Can Radius or Tacacs help?

Re:snmp

It is possible to do snmpwalk of the whole mib tree to see what is
there.

I don't know if this really returns everything but it does return a
lot.

"C:\Program Files\Support Tools>c:\usr\bin\snmpwalk
-c xxxxx 172.20.1.1 mib-2"

system.sysDescr.0 = Cisco Internetwork Operating System Software
IOS (tm) C3500xl Software (C3500xl-C3H2S-M), Version 12.0(5)WC5,
RELEASE SOFTWAR
E (fc1)
Copyright (c) 1986-2002 by cisco Systems, Inc.
Compiled Tue 28-May-02 11:41 by devgoyal
system.sysObjectID.0 = OID: enterprises.9.1.248
system.sysUpTime.0 = Timeticks: (854730910) 98 days, 22:15:09.10
system.sysContact.0 = MCL HelpDesk 07002 663328
system.sysName.0 = MCL_SW1
system.sysLocation.0 =
system.sysServices.0 = 2
system.sysORLastChange.0 = Timeticks: (0) 0:00:00.00
interfaces.ifNumber.0 = 28
interfaces.ifTable.ifEntry.ifIndex.1 = 1
interfaces.ifTable.ifEntry.ifIndex.2 = 2
interfaces.ifTable.ifEntry.ifIndex.3 = 3
interfaces.ifTable.ifEntry.ifIndex.4 = 4
<..snip..>

I would not recommend doing this on production kit since
some platforms find it hard going and you might even bump into
some bug.

 

Thank you very much for info - I am on it, as we "e-speak"

 

Papi wrote initially:

Could anybody point me to a detailed documentation on the workings of DHCP
services in Cisco products (specifically for the 6500 family). Problems I
am trying to address (perhaps some kind soul may already have answers?!?):
- I am trying to pull the information about the various VLANs-assiggned IP
addresses, vs. MACs of end points, through SNMP - and can't find the dam'
OIDs.
- I am trying to run a script (TCL-expect-based) to pull additional info
from the DHCP information, but could not find a way to show onlyh specifis
VLANs (the show ip dhcp binding gets me everything, and I am forced to
take this info "out", and process it via awk) - I would like to have a
sppecific port ALWAYS getting the same IP address, no matter what device
gets plugged in (so it is NOT a MAC-to-port type of associatian, as the
MAC changes continuously, but rather an IP-from-DHCP-to-port restriction)
.... I wonder if this is even possible?!?

TIA,
Papi

I have read the docs you've pointed out, but - though useful info - it is
not what I was looking for. It relates mostly to the mechanism of DHCP,
in general, and possible "contribution" of Cisco, in regards to such
traffic, not Cisco's own equipment providing such services, and
information related to it. I have changed the subject, in the hope that it
may raise someone else's interest

Thanks again,
papi

 

On Wed, 19 Jan 2005 11:31:50 -0800, anybody43 wrote:

<SNIP>

I did that in my first attempt to address my problems - for whatever
reasons I could not pick up anything related to the initial request. Thank
you for your suggestion - I'll keep looking around, also.

 

This may be of some helps as well ..

http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t1/easyip2.htm

Drop the ZZZ to reply

Cheers ...