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Author Topic: Nodes are discovered with IP 0.0.0.0  (Read 6938 times)

kamintech

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Nodes are discovered with IP 0.0.0.0
« on: June 04, 2013, 08:23:13 PM »
I'm still a newbie to the NeDi program so my problem may be to my lack of knowledge of how everything works. I've setup my seed devices and it is finding other CDP neighbors correctly and adding them but when a new Node is discovered, it finds the MAC on the correct port but the DNS name and the IP information is not resolved. It comes back as Node 012345689 appeared on Fa0/3 V|1 as - with IP 0.0.0.0, with the exception of my servers and just a few Windows computers. It appears as if the DNS resolution is not working.
I can use the Network Tool box and do a lookup on my ip ranges and it will resolve the names and the IP address information correctly. What am I overlooking? Any help would be appreciated very much.

rickli

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Re: Nodes are discovered with IP 0.0.0.0
« Reply #1 on: June 05, 2013, 12:18:29 AM »
You need ARP chaches of routers (and FWs). You might see some 0.0.0.0 at first, but they should be updated over time. If you don't have a usable L3 device, you could use arpwatch instead...
Please consider Other-Invoices on your NeDi installation for an annual contribution, tx!
-Remo

kamintech

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Re: Nodes are discovered with IP 0.0.0.0
« Reply #2 on: June 05, 2013, 07:29:11 PM »
Thanks for the quick reply. Unfortunately we are only allowed SNMP read access to our routers and most of our infrastructure are L2 devices. How do I get the arp caches? How do I use arpwatch? I see the #arpwatch in the nedi.conf but where are the files located?
 

rickli

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Re: Nodes are discovered with IP 0.0.0.0
« Reply #3 on: June 05, 2013, 09:44:50 PM »
SNMP read is just what you need. Checkout the the Defgen tutorial on my Youtube channel, if your routers don't reveal anything...
Please consider Other-Invoices on your NeDi installation for an annual contribution, tx!
-Remo

kamintech

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Re: Nodes are discovered with IP 0.0.0.0
« Reply #4 on: June 11, 2013, 02:33:22 AM »
I've used degen and made some changes and this seems to have corrected all but one remaining router. This is a Cisco 3750 that I have snmp ro access. When I run nedi I get the following error: Arp (SNMP) ------------------------------------------------------------------ SNMP:Connect 157.126.146.202 specialro v2 Tout:2s MaxMS:1472 ERR :ipNetToMedia The requested table is empty or does not exist ARPS:0 IP and 0 IPv6 entries found.

Does this mean that there are no arp tables/entries on this router. Is there other way for me to obtain the IP/mac information? I did notice that the model is showing 3750 but the boot image shows  cisco1760 Cisco IOS Software, 3700 Software (C3725-ADVENTERPRISEK9-M), Version 12.4(6)T2.
Thanks in advance for your help!!! :) :)

rickli

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Re: Nodes are discovered with IP 0.0.0.0
« Reply #5 on: June 12, 2013, 12:13:32 AM »
It's possible that this table is empty, but click through all ArpND buttons to check whether the popup window shows any entries with other OIDs.

Well, if the model is really a cisco1760 the .def is probably wrong (copied from a 3750?) and should be fixed (and returned to me) :)

Is it not 1.3.6.1.4.1.9.1.416.def?
Please consider Other-Invoices on your NeDi installation for an annual contribution, tx!
-Remo

kamintech

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Re: Nodes are discovered with IP 0.0.0.0
« Reply #6 on: June 18, 2013, 02:33:17 AM »
I've tired several different defs and every combination on the ARP/ND with no success. The 1.3.6.1.4.1.9.1.416 does seem to be the correct def for this router. Is there any thing else that I might try? It would be nice to get the IP/DNS information for this location.


dobst

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Re: Nodes are discovered with IP 0.0.0.0
« Reply #7 on: June 18, 2013, 02:23:49 PM »
First of all make sure, the arp table is filled. At the command line type one of these commands:

Code: [Select]
yourswitch#show arp
yourswitch#show ip arp

then try to read snmp data (modify community and snmp  version):

Code: [Select]
snmpwalk -v2c -c public [switch ip] .1.3.6.1.2.1.4.22.1.2

which cisco model do you want to poll exactly?

kamintech

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Re: Nodes are discovered with IP 0.0.0.0
« Reply #8 on: June 19, 2013, 04:58:18 PM »
Since this is a router and I only have snmp ro access, I'm not able to get to a command line on the router itself. I did run the snmpwalk to the device and it comes back with: IP-MIB::ipNetToMediaPhysAdress =  No Such Object availalbe on this agent at this OID. The router model is Cisco 3725.
I'm not familiar with the internal working of routers so is it possible that this model does not have the capability of displaying the IP addresses? Is there any other way to get them?


« Last Edit: June 26, 2013, 01:53:18 PM by kamintech »

rickli

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Re: Nodes are discovered with IP 0.0.0.0
« Reply #9 on: June 27, 2013, 07:33:14 PM »
Apparently not in ipNetToMediaPhysAdress , but did you try other MIBs in Defgen?
Please consider Other-Invoices on your NeDi installation for an annual contribution, tx!
-Remo

kamintech

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Re: Nodes are discovered with IP 0.0.0.0
« Reply #10 on: June 28, 2013, 08:55:51 PM »
Remo,
Yes, I have tried different mibs in Defgen and all with the same results. I've contacted the vendor who maintains this router and he is able to do a 'show arp' an 'show iparp' and display the results. After digging around on the Cisco site I think the problem may be with the version of IOS. This router is running 12.4(6) and I don't see where it will support the IP-Mib (IP-MIB::ipNetToMediaPhysAdress -1.3.6.1.2.1.4.22.1.2). I'm able to do an snmpwalk on 1.3.6.1.2.1.4.20 successfully. The vendor has agreeded to upgrade if I can tell what version the IOS needs to be.
 
« Last Edit: July 01, 2013, 03:03:54 AM by kamintech »