OK - perhaps I have failed in my search attempts. If this is the case and the "right answer" is "RTFM - look here" I'll apologize for the search fail - and will be grateful for the pointer. That said - I've not found much in the way of documentation for Network Atlas and I am struggling to understand how link status is determined. In short, I have a number of links / connections that show as "down" despite the fact that I know they are up. It appears that a common factor in the links with this condition is a lack of a CDP relationship between the devices. In one case the interfaces between our firewalls' inside interfaces and the corresponding switch interface (L2 connectivity) shows down despite both interfaces being up and passing traffic. The firewalls are not CDP participants. In the other case, links between a couple of HP Procurve switches are shown as down. In both case sets I have done the following: physical cross connect between the devices has been verified In each case there is NOTHING between the two devices except a single ethernet patch cable. mac address tables on both devices show the other device as the peer device on the port in question. traffic is flowing on the link between the devices the Network Atlas link has been opened (right click > properties) and the the generic related interfaces have been applied (drag and drop from the managed node in the list) When viewing the related interfaces in Network Atlas Link Properties they show "Status:Object status is Up" The same configuration / configuration approach has been applied to other linked interfaces and where the two devices are both CDP enabled life is good and the links show up/down condition properly So - Network Atlas is using SOMETHING other than the relationship that I establish between the interface objects that I establish in the map, and the related link status, to determine the health of the link. I can not find documentation that tells me how this determination is being made - and more importantly how I can build a map that accurately reflects the condition of my environment without CDP between these devices. Thanks in advance...

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Network Atlas - Link Status Issue

nathan.miller over 9 years ago

OK - perhaps I have failed in my search attempts. If this is the case and the "right answer" is "RTFM - look here" I'll apologize for the search fail - and will be grateful for the pointer. That said - I've not found much in the way of documentation for Network Atlas and I am struggling to understand how link status is determined. In short, I have a number of links / connections that show as "down" despite the fact that I know they are up. It appears that a common factor in the links with this condition is a lack of a CDP relationship between the devices. In one case the interfaces between our firewalls' inside interfaces and the corresponding switch interface (L2 connectivity) shows down despite both interfaces being up and passing traffic. The firewalls are not CDP participants. In the other case, links between a couple of HP Procurve switches are shown as down.

In both case sets I have done the following:

physical cross connect between the devices has been verified In each case there is NOTHING between the two devices except a single ethernet patch cable.
mac address tables on both devices show the other device as the peer device on the port in question.
traffic is flowing on the link between the devices
the Network Atlas link has been opened (right click > properties) and the the generic related interfaces have been applied (drag and drop from the managed node in the list)
When viewing the related interfaces in Network Atlas Link Properties they show "Status:Object status is Up"
The same configuration / configuration approach has been applied to other linked interfaces and where the two devices are both CDP enabled life is good and the links show up/down condition properly

So - Network Atlas is using SOMETHING other than the relationship that I establish between the interface objects that I establish in the map, and the related link status, to determine the health of the link. I can not find documentation that tells me how this determination is being made - and more importantly how I can build a map that accurately reflects the condition of my environment without CDP between these devices.

Thanks in advance...

Top Replies

superfly over 9 years ago +2

I just use one of the interfaces at either end. Although in some cases, even though the link goes down, the interface in fact does not. So in those cases I use either a tunnel interface or I use UDLD.…

0 nathan.miller over 9 years ago

Bump - help?
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0 superfly over 9 years ago

I just use one of the interfaces at either end. Although in some cases, even though the link goes down, the interface in fact does not. So in those cases I use either a tunnel interface or I use UDLD.
Hope that helps.
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0 cobrien1 over 9 years ago

Did you use the "Connect Now" function in Network Atlas to connect your nodes or did you manually connect them?
Also, what do you see when you click the line and click "Line Properties..." in the "Lines" section of the ribbon bar at the top?
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0 nathan.miller over 9 years ago in reply to superfly

Thanks for this... I may fall back to something like this but for the moment I want to try to make the solution properly recognize the link as it actually exists.
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0 nathan.miller over 9 years ago in reply to cobrien1
I am increasingly convinced that the issue lies in Network Atlas relying on CDP and not trusting the manually created link. Note that in the clip above Network Atlas sees both interfaces as "Up." I am seeing this symptom only in cases where the link exists between devices that do not share CDP information.
Cisco CDP is in place and functioning between Cisco routers and switches. These map links all function properly.
HP has a derivative of CDP (or perhaps just an aliased LLDP implementation) and links between the HP switch infrastructure show properly as well.
The firewalls are not CDP enabled nor are the filers. Links between the filers and both Cisco and HP switches show as down in the map despite both interfaces showing as "Up" in the link properties (as shown above).
Links between the Cisco and HP switch fabric also represent as down in the map - again with the actual interfaces being recognized as Up in the link properties.

ConnectNow
I have used the "ConnectNow" function and it does not find these layer 2 links. If I delete a troubled link, select the two devices, and click the "ConnectNow" button on the ribbon menu and select "Connect L2 Connections" I get the following:
If I do the same between two devices that share CDP information the link is created and functions properly.
I can not imagine that Network Atlas is incapable of representing links without CDP information - but it sure seems that this is the case. Thoughts?
I know that the link exists at layer 1 and 2 (I personally cross connected the interfaces directly to one another).
Link Properties
Selecting the "Line Properties" item from the ribbon menu gives the same interface as the one I used to set the line endpoints (I got to it with "right-click > properties"). The bold text is the interface id / label from the interface in question. I have blacked out a portion of the label on the first interface to comply with security policy (it includes the neighboring device name)...
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0 cobrien1 over 9 years ago in reply to nathan.miller

With manually created links, Network Atlas should get the link status solely and exactly from the items you've configured under "This link gets its status from:" that you show above. I see in your screenshot both are seen as up. Mousing over that in the web UI shows the link as down? That's very strange. I'd suggest it's time to open a support case to look into it.
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0 nathan.miller over 9 years ago in reply to cobrien1

When I mouse over the link in the NPM web UI I see the following (node names removed):
This is on the same link that produced the image in the "Link Properties" section in the early post (both interfaces are up etc...) Before I took this screen shot I rediscovered the nodes in question and ensured that the interfaces on those nodes were included in the monitored set.
I guess support case it is...
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0 extremesanity over 9 years ago in reply to nathan.miller

I would LOVE to know what you find out, I have this exact problem also.
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0 jasongay over 9 years ago in reply to extremesanity

Has anyone received any update on this issue? I am experiencing the same - and definitely do not want to rely on CDP.
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0 psellittosw over 9 years ago

I am also experiencing this issue, and I have a ticket opened on it and will share what I find.
I am running NPM 10.7 and Network Atlas 1.11.0.167
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