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All Primary Routers have .0 Polling IP

I am starting to scan in devices on my network and have a strange issue when doing subnet scans. All my primary routers are getting assigned a .0 polling address, then showing as down immediately once added to SolarWinds. I am having to manually touch each one and change it. The backup routers are not having this issue. Any ideas on why this would be happening?

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cnorborg

Never heard of that happening? Maybe some more details like the configuration of the interface for the subnet its doing this for? Brand of router? Assuming your doing "Network Discovery" in Orion, or are you using another method of adding them?

Are you scanning for loopback interfaces, management interfaces or a physical interface?

dburns865

Thanks for the reply. It is doing this on CIsco 2801 routers and the issue is happening on one of the subinterfaces. On that subinterface, we just have an IP, a VRRP address and flow settings. I am using Network Discovery and just adding a /16 subnet with all the default scan settings. The weird thing is it's not happening to the backup routers, which are the same models and config, just with a different IP and lower VRRP priority.

cnorborg

Tried doing a discovery on a router of mine, but it didn't have this issue. Maybe post the configuration of the interface its having the issue with?

Are you monitoring your routers using a WAN or LAN interface? Have you considered using a loopback interface instead? Definitely a much better practice for managing Layer-3 devices, or anything that routes in other words. If you're using a LAN sub-interface, and that connection goes down, the loopback will still be up and as long as you can still route to it, you can gain valuable info about why the device might be having issues.

The value of manging via loopback addresses...

dburns865

Currently with WuG we monitor both the WAN interface and the LAN interface, which are both associated with one node. Both of those monitors are tagged as "Critical" so if one goes down, the device will go into the "Down Device" list even though it is still reachable. That seems superior to me as if you see one go down but not the other, you have already ruled out a lot of potential issues. Thanks for the suggestion, if we end up sticking with SolarWinds that is most likely what I will do as it seems like the best alternative. Here is my config

interface FastEthernet0/0

bandwidth 100000

no ip address

no ip redirects

no ip unreachables

no ip proxy-arp

ip flow ingress

duplex auto

speed auto

no mop enabled

interface FastEthernet0/0.X

description X

encapsulation dot1Q X

ip address .2

ip helper-address.50

ip flow ingress

ip nat inside

ip virtual-reassembly

vrrp 1 ip .1

vrrp 1 timers advertise 3

vrrp 1 timers learn

vrrp 1 preempt delay minimum 10

vrrp 1 priority 200

no cdp enable

rschroeder

Darn, I'd like to help, but with a hundred+ routers, some with several dozen SVI's or sub-interfaces, I can't duplicate the issue here.

I bet you're well aware that the 2801 stopped being sold in 2011 and it went EOL/EOS in 2016. For best security you might advice your management to budget for a forklift upgrade soon.

Still, even with EOS Cisco routers SW ought to be able to recognize their physical and logical interfaces accurately and not assign .0 addresses. I don't have any routers old enough to compare with yours, but my newer routers have sub-interfaces being automatically discovered correctly.

Hmmm. A .0 address . . . It does sort of remind me peripherally of sub-interface addressing being truncated. If you have sub-interface GigabitEthernet0/0.1234, how would it end up looking like 0/0.0? I'm probably off on a false lead with sub-interfaces.

Watching. I'll be interested to see the cause. Maybe others with 2801 can help!

Swift Packets!

Rick Schroeder

dburns865

Thanks for the input, I appreciate you trying to replicate it. Yes they definitely need to get replaced, we are currently flying out to each of our branches and replacing their entire rack. With only 3 of us it takes a while!

The other weird thing is, all the correct IPs are still there so its not like the .0 took the place of another one. I would think if it was an issue with the sub-interface one of the correct IPs would be missing? Im not sure, interesting thought.