[SNMP4J] Re: Pulling Router tables via SNMP

[Charlie Hubbard]

Phil,

Yes this is good information to get started.  The RFC number was very
helpful.  I remember the Net-SNMP program from a while back, and
walking routers is essentially what I want to do to trace the network
out.  I just want to write a tool using SNMP4J and Mibble to do the
walking.

Thanks
Charlie

On 10/11/06, PHIL BERGSTRESSER <phil.bergstresser at adtran.com> wrote:
> Charlie,
>     The first hurdle is to get SNMP access to the router, which requires
> admin knowledge. Perhaps you have that. That's because you must know the
> community name and what version of SNMP is usable. This stops most
> people just starting.
>     You can explore various utilities for accessing the router tables
> once you have that information. Having specific MIBs makes this easier
> because you get symbolic clarity. Just to show how you can access the
> standard IP routing table defined in RFC2011, I used a command line
> utility I have used for years that is from the NET-SNMP project (used to
> be UCSD-SNMP originally). Of course, since this is sn SNMP4J list, it
> would be appropriate to recommend something from here. Even if you don't
> have a MIB loaded, but do have the community name, you can see raw OIDs
> with the table values to know that you are getting access to the data
> you want. Here is an example of a walk of the IPRouting table index in
> the standard RFC2011 MIB which every router with SNMP support should
> support. I used the numeric OID, but in fact had the MIB loaded so it
> came out interpreted. (This is in fact not from a router). The walk is
> sent to host "demo.test" with community name "public" and starting OID
> "ipRouteDest=.1.3.6.1.2.1.4.21.1.1". Is this the type of some
> information you are looking for, and a help to see how to approach it?
>     I would recommend looking at the standard RFC MIBs before delving
> into enterprise specific MIBs.
>
> D:\SNMP\mibs>snmpwalk demo.test public .1.3.6.1.2.1.4.21.1.1
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.0.0.0.0 = IpAddress: 0.0.0.0
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.0.0.0 = IpAddress: 10.0.0.0
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.2.27.250 = IpAddress:
> 10.2.27.250
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.5.252.100 = IpAddress:
> 10.5.252.100
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.5.254.119 = IpAddress:
> 10.5.254.119
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.5.254.145 = IpAddress:
> 10.5.254.145
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.14.1.2 = IpAddress:
> 10.14.1.2
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.26.44.51 = IpAddress:
> 10.26.44.51
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.254.0.0 = IpAddress:
> 10.254.0.0
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.254.1.1 = IpAddress:
> 10.254.1.1
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.254.1.120 = IpAddress:
> 10.254.1.120
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.254.1.122 = IpAddress:
> 10.254.1.122
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.254.1.125 = IpAddress:
> 10.254.1.125
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.254.1.200 = IpAddress:
> 10.254.1.200
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.254.2.98 = IpAddress:
> 10.254.2.98
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.254.254.254 = IpAddress:
> 10.254.254.254
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.254.255.255 = IpAddress:
> 10.254.255.255
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.255.255.255 = IpAddress:
> 10.255.255.255
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.127.0.0.1 = IpAddress:
> 127.0.0.1
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.172.22.48.13 = IpAddress:
> 172.22.48.13
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.172.22.48.47 = IpAddress:
> 172.22.48.47
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.172.22.48.48 = IpAddress:
> 172.22.48.48
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.172.22.116.192 = IpAddress:
> 172.22.116.192
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.172.30.21.10 = IpAddress:
> 172.30.21.10
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.224.0.0.0 = IpAddress:
> 224.0.0.0
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.255.255.255.255 = IpAddress:
> 255.255.255.255
>
>     I would have gotten the same results in my case with a symbolic
> reference since I did have the MIB:
>
> D:\SNMP\mibs>snmpwalk demo.test public ipRouteDest
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.0.0.0.0 = IpAddress: 0.0.0.0
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.0.0.0 = IpAddress: 10.0.0.0
> ip.ipRouteTable.ipRouteEntry.ipRouteDest.10.2.27.250 = IpAddress:
> 10.2.27.250
> . . .
> . . .
>
>
>     HTH,
> Phil
>
>
> > -----Original Message-----
> > From: snmp4j-bounces at agentpp.org
> > [mailto:snmp4j-bounces at agentpp.org] On Behalf Of Charlie Hubbard
> > Sent: Wednesday, October 11, 2006 7:21 AM
> > To: Rory Marquis; snmp4j at agentpp.org
> > Subject: [SNMP4J] Re: Pulling Router tables via SNMP
> >
> > Rory,
> >
> > Thanks for the info.  Both sites are very helpful.  What my
> > ultimate goal in doing this is try and map the network by
> > using snmp to figure out what networks a router is
> > connecting.  I've used some products that seem to use this
> > same approach so I figured it would be doable.
> > Do you have any other insight in how I might accomplish this goal?
> >
> > So SNMP4J doesn't parse MIBs and that's why I need mibble?
> >
> > Thanks
> > Charlie
> >
> > On 10/10/06, Rory Marquis <roridge at hotmail.com> wrote:
> > > Hi there
> > >
> > > Im not sure if what you are asking would be posssible in
> > the way that
> > > you might be thinking.  (Although I am sure that someone
> > will correct
> > > me if I am worg.
> > >
> > > The only way that a router that supports SNMP could tell you the
> > > routing tables would be if it had a MIB that would provide you with
> > > this information.
> > >
> > > You said that you have read the RFC, and I agree at first they are
> > > difficult to follow. The thing is there might be LOTS of
> > RFCs for the
> > > MIBs of your routers/switches there also might be private
> > MIBs for the
> > > routers that are manufacture specific (in fact i can
> > guraentee that there are).
> > >
> > > My advice to you is to do some more research. Start small just by
> > > using an OID from something like the HOST-RESOURCES-MIB or the
> > > SNMPv2-MIB or something like that and throw it at the
> > router to see if
> > > it A: implements SNMP (some don't, honest) and B: that you
> > can talk to
> > > it.  Then what I would do is download the MIB from the RFC
> > and parse
> > > it using something like Mibble http://www.mibble.org/. There is an
> > > excellent tool that the Mibble folks have created which will parse
> > > MIBs for you, and send SNMP messages... it's a good tool to
> > use if you are just playing around.
> > >
> > > Then I would go searching for more MIB information regarding your
> > > specific Routers. If they are Cisco you are in luck, take a look in
> > > the Mib Depot http://www.mibdepot.com/index.shtml
> > >
> > > HTH
> > >
> > > Cheers
> > > Rory
> > >
> > >
> > >
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>