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Need assistance setting up Subnet, IPs, and reservations in IPAM

Apologies for the long post. I'm pretty new to this and want to make sure I understand before implementing it. Currently we have an Excel spreadsheet to track our subnets, hosts, and static IP addresses. Ideally we would like to replace this and use IPAM exclusively. However there are a few questions and concerns about how to best set this up. Let me give you some background:

a) SolarWinds already added a number of our subnets based on DHCP servers

b) We have static and DHCP addresses on the same subnet. Typically .30-254 are set aside as DHCP.

c) We want to reserve 001-009 on each subnet for network equipment. We don't do DHCP reservations. At the moment we confirm an IP is available, add the host/description to the IP spreadsheet, assign the IP on the device, and add a DNS entry where appropriate.

d) We have a hostname or description for all assigned static IP's in the Excel file, however many of these are not in DNS (some descriptions are literally just printer make/model)

e) We track external IP's for our ISP equipment

I manually added a subnet and found that it sets all IP addresses to static, rather than using the DHCP scope setting. (I can tell it isn't linked to the DHCP server like the auto-imported ones) My first thought was to set the DHCP addresses as dynamic. Alternatively set our actual static addresses to Reserved, but this SolarWinds doc says these IP's may not be assigned to a network device - http://www.solarwinds.com/NetPerfMon/SolarWinds/wwhelp/wwhimpl/js/html/wwhelp.htm#context=SolarWinds&file=OrionIPAMPHStatus.htm

Based on other comments on Thwack, I believe a device could still use this address, and then it would change from Reserved to Used. However, my understanding is when this device is no longer in use, the IP will go to a Transient state and ultimately return to Available, rather than Reserved like we want. I realize I can adjust the Transient settings, but I assume there is a reason you don't want this completely off.

So at the moment, I am leaning towards keeping the existing subnets with the proper DHCP scope info and manually add what's missing. So my questions are -

1) How can I tell SolarWinds to not assign a specific group of IP addresses (e.g. 001-009) and not use ones in the DHCP scope?

2) How do you track the description for devices that aren't in DNS? Manually add in hostname, node alias, or comment field? Or a custom property?

3) How do you track external IP's for ISP equipment?

  • 1) How can I tell SolarWinds to not assign a specific group of IP addresses (e.g. 001-009) and not use ones in the DHCP scope?

    - If it is linked to the DHCP, it would be retained as reserved.  The scenario you are describing is only true for stand alone subnets that is not linked to the DHCP scope

    2) How do you track the description for devices that aren't in DNS? Manually add in hostname, node alias, or comment field? Or a custom property?

    - If it is not in the DNS, it would be NULL.  Alias, Comment and Custom Property are native on the IPAM and is stored Database.  They remained unaltered unless you manually changed it.

    3) How do you track external IP's for ISP equipment?

    - same as internal ones, via ICMP for status and SNMP for other information

  • donrobert5  wrote:

    1) How can I tell SolarWinds to not assign a specific group of IP addresses (e.g. 001-009) and not use ones in the DHCP scope?

    - If it is linked to the DHCP, it would be retained as reserved.  The scenario you are describing is only true for stand alone subnets that is not linked to the DHCP scope

    Is there a way to link a DHCP scope to a subnet after I import it? Additionally, it seems that SolarWinds will grab addresses from the DHCP scope if I request enough IPs (I haven't gone through with the request, but it seems to offer them as suitable static addresses). Is this a bug that needs to be fixed or will it create a DHCP reservation for those addresses?

  • once you added the DHCP server and scan the DHCP server, it should automatically linked to the existing subnet.  However, you need to make sure that it fits the subnet.

    If not, then don't add subnet manually and let IPAM scan the DHCP server and it will detect and add it in IPAM.  However, it will be on the discovered subnets group.  You just have to re arrange them later.

    As for your 2nd question, sorry, can you be more specific, I do not seem to get the scenario here.

  • Regarding "SolarWinds will grab addresses from the DHCP scope if I request enough IPs", this is the scenario:

    On a particular subnet, I have .30-254 set aside as DHCP addresses. We use .1-29 as static addresses and manually track/assign them.

    In SolarWinds, I go to My Dashboards - IP Addresses - Request IP Address. If I request 31 addresses, it will assign .1-29, as well as .30 and .31 (for a total of 31 addresses). It should not be offering .30/31 as those are in the DHCP scope.

    So my question was - is this a bug or is it intentional (e.g. SolarWinds would then create a DHCP reservation for .30/31)?