Host Monitoring

[pmoorey]

I have a requirement to monitor various windows hosts, the problem I have is that I am not able to make outbound connections to them, from a central server, this makes using applications like NAGIOS difficult.

Does anyone know a way of establishing connections from a remote client to a central server, which is then enable to monitor latency, up time etc?

I have multiple computers at remote locations, connected via the internet, but it is not possible for me to establish connections over the internet to them, port forwarding etc. is not an option, hence my requirement to make the remote clients establish the connections.

Thanks in advance!




Peter
CCNA, Cisco Qualified Specialist

 

[burtsbees]

So...you're trying to monitor various hosts over the internet from a central location? Are they all in the same company? Do vpn tunnels exist? Am I totally missing your goal? What kind of server?

Burt

 

[pmoorey]

Hey Burt,

Thanks for your response.

Basically I have numerous windows computers all sat in different locations, with internet connections. I have no management control over the remote sites, or any inbound access to the sites, for example ICMP.

What I need to do is have a single webpage, it will have an up/down status for all the remote computers (basically whether the computer is online or not).

The clients would need to establish a connection outbound to a central server over the internet. The server would identify the client by it's source IP and would recognise it as being "online".

It would theoretically operate in a similar way to dyndns, in that the remote computers 'phone home' to advise the server of their new IP addresses - if you see what I'm getting at!

The key objective is that my webpage would indicate which computers are online or not...

Peter
CCNA, Cisco Qualified Specialist

 

[pmoorey]

Regarding the server, I'd like to use something like Nagios or Solarwinds or anything those monitoring tools...

Peter
CCNA, Cisco Qualified Specialist

 

[burtsbees]

As far as the server goes, I was asking about the make/model, hardware-wise, but I was not sure of your goal (was thinking of something like in IBM, the RSA ability to mount a drive and run a separate virtual server).
Do you mean, like make a .bat file for the computers to ping the server whenever it goes online, but a different protocol other than ICMP?
Do you need a connection that is always on, just when the computers go online to the internet, or something like that? What about pointing the remote locations' routers to a syslog server at the central site and run a syslog daemon (like kiwi) in the backround? This is assuming that the central has a static IP address, because I don't think you can config a Cisco router to point to a dns name for snmp or logging server...
Is it syslog, packet sniffer, or some proprietary program that you are wanting to use? Is NBAR not good enough for what you need?

Burt

 

[kcusscam]

Its not a cisco solution but I have a few clients that work in the same way. SNMP might be a good choice, look into zenoos, you can use zenoos plugins, nagios plugin and plain old snmp. It sounds like your issues is connecting to the remote machines due to lack of static addressing or ability to do port forwarding. What you may want to think about is a client side vpn. I would use a vpn that uses little traffic when not in use, ie one that uses udp; look into an openvpn server/client.

Jeremy

 

[pmoorey]

Thanks Burt/Jeremy.

Sorry, I may have confused things by putting this post in the cisco router forum, I wasn't sure what to classify it as...

"Do you mean, like make a .bat file for the computers to ping the server whenever it goes online, but a different protocol other than ICMP?"

Yes, something like that, basically I'd love to use SNMP or ping to check if my remote hosts are responding, but this is not possible as I can't port forward etc, VPN is not an option either unfortunately.

So I was hoping to reverse the monitoring so that the remote computers would tell the central server that they are online.

Peter
CCNA, Cisco Qualified Specialist

 

[kcusscam]

If you can't do port forward or vpn than I think you are out of luck.

If you need to monitor a server why can't you install a vpn client of the machine its self, no need to change anything on the network?

Jeremy

 

[burtsbees]

I would post in the VB forum. I am sure there is something like
10 input a when iexplore.exe
20 make a=1
30 if a=1 then goto 40
40 do

https://x.x.x.x

user bla pass blabla

Or some crap...been since 1985 since I actually programmed any BASIC...lol

In other words, I am sure this can be done via VB6, as it can ping or any protocol via any port (TCP or UDP) to any destination, https with any username/pass, and when that happens, the server can be scripted to email you or write to a text file anywhere using simple windows command line stuff.

Burt

 

[pmoorey]

My organisation already has a VPN solution, but it requires a user to actively log in, i need this software to unattended, as these PCs are often unattended.

Technically what I want to do is possible, it is just knowning how to implement it.

Software running permanently on each remote computer could connect by TCP to a central server, facing the internet. the server would be aware of which clients are connected by their source addresses, and as long as the TCP connection remained established the server would know the client is 'up'.

If you think about it, trojan horses (for example) establish outbound connections toward specific addresses, this enables someone to then gain remote control. I want to be able to do something similar, but I just want to know that the host is online.

Peter
CCNA, Cisco Qualified Specialist

 

[pmoorey]

Burt, I think you are right about VB...

I think it would be reasonably simple to implement a script on the client side to connect periodically to announce it's self as online... even a http-put would suffice.

The hardest part I imagine would be to configure the server side to have a map with up/down status based on the client initiating the connection...

Peter.

Peter
CCNA, Cisco Qualified Specialist

 

[kcusscam]

A script would work as long as the user is logged in. I assume that you need it work work regardless if the user is logged in or not. If you do then you will need to script to run as a service, assuming you are talking about windows. I don't think a script can runs a service but you could do it in VB.NET and compile it to run as a service. Also if we are talking about Windows you can srvany to execute a regular command regardless if a user is logged in. Also a schedule task may do it but a service would probably work best especially if the "app" could establish the connection and accept feedback then you "ask" it for any information about the system instead of just "are you there".

So if a vpn and port forwarding are out then yes you will need a script, service or application to be your helper.

 

[Supergrrover]

You can use the "at" command to run scripts under a different account at a specific time/schedule.

http://support.microsoft.com/kb/313565

You can also use the sleep command in the 2003 resource kit -

http://malektips.com/xp_dos_0002.html

and loop it. - Check the resources to see what this uses for CPU.


Brent
Systems Engineer / Consultant
CCNP, CCSP

 

[burtsbees]

A script would work as long as the user is logged in. "

How else would a user be online?

Burt