Path: utzoo!utgpu!watserv1!watmath!att!linac!pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!think.com!barmar
From: barmar@think.com (Barry Margolin)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Cisco information needed
Keywords: Cisco
Message-ID: <1991Feb22.214833.10898@Think.COM>
Date: 22 Feb 91 21:48:33 GMT
References: <1991Feb21.215233.26519@ncsu.edu>
Sender: news@Think.COM
Organization: Thinking Machines Corporation, Cambridge MA, USA
Lines: 37

In article <1991Feb21.215233.26519@ncsu.edu> dbjoyner@eos.ncsu.edu (David Joyner) writes:
>I need some information regarding Cisco routers.  Specifically, how can I
>query the Cisco with SNMP (or some other protocol) and get information
>about subnets that the router services as well as what machines are on
>these subnets?  The technical information that I have available is lacking.

Do you have "The Simple Book" by Marshall Rose, which describes SNMP?  If
you're going to be using SNMP much I suggest you run, don't walk, to a
bookstore with a good technical section and get it.

To find out the IP addresses of an interface, you find the rows in the
ipAddrTable where the ipAdEntIfIndex is the interface number.  The
corresponding ipAdEntAddr is the address of that interface.  You can also
get the corresponding ipAdEntNetMask to get the subnet mask, and apply this
to the address to get the subnet address.  By doing this for all the
interfaces, you can get a list of all the subnets connected to the router.

If you want to get a list of all the subnets that the router knows about,
you should dump the ipRoutingTable.

I don't think the router maintains a list of all the machines on a subnet
(how would it get such a list?), so there's no way to list it with SNMP.
If you have accounting turned on you may be able to get a list of all the
hosts that have used the router.

You can also FTP cisco's enterprise MIB from ftp.cisco.com.  This documents
all of cisco's implementation-specific extensions to the MIB.

>I would appreciate it if a programmer from Cisco could mail me...

You should send mail to customer-support@cisco.com if you want response
from cisco.
--
Barry Margolin, Thinking Machines Corp.

barmar@think.com
{uunet,harvard}!think!barmar


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