Not all ip adresses for Switches and Routers being discovered

[edzon]

I am currently discovery routers and switches for a customer but for some reason the source ip (the ip used to discover the device) is not being mapped to any field in the cmdb, for instance, we discovered a router using the ip 10.50.199.100 so our customer is expecting to have this source ip (10.50.199.100) in some field in the cmbd, but this ip is not at any attribute of the ci, neither ip_address or any related list such as network adapters or CI IPs.

I went through the payloads and noticed that discovery is ignoring ip addresses with IfType 24 which seems to be loopbacks,

Does anybody knows Why are loopbacks interfaces/ip adrresses ignored? how can I change this behaviour?

<ipAddrEntry instance=".4.10.50.199.100">

<ipAdEntAddr type="SnmpIPAddress">10.50.199.100</ipAdEntAddr>

<ipAdEntIfIndex type="SnmpInt32">335544420</ipAdEntIfIndex>

<ipAdEntNetMask type="SnmpIPAddress">255.255.255.255</ipAdEntNetMask>

</ipAddrEntry>

<ifEntry instance=".335544420">

<ifIndex type="SnmpInt32">335544420</ifIndex>

<ifDescr type="SnmpOctetString">loopback100</ifDescr>

<ifType type="SnmpInt32">24</ifType>

<ifPhysAddress type="SnmpOctetString"/>

<ifAdminStatus type="SnmpInt32">1</ifAdminStatus>

<ifOperStatus type="SnmpInt32">1</ifOperStatus>

</ifEntry>

<ifEntry instan

Business Critical: Significant Impact

Affected Users: All Users

Start Date: 2017-03-23 14:19:52

End Date:

[bharath10]

Hi Anusha,

could share your steps, to fix this. having same kind of issue.

where Infra team wants Loopback IP on CI. and during discovery ip address are getting change/update as endpoints have multiple IP address.

Thanks in advance.

R's,

Bharath

[sathish_anoor]

Hello @anusha.narapuram ,

We are having this issue.  Can you please post the solution you used?

Thanking  in  advance, 

Sathish

[Greg Hubbard]

It is a common practice in network engineering to use a loopback interface on network gear (especially routers) for the "management address."  I believe that ServiceNow discovery, by default, drops any interfaces of type "loopback".  This makes sense for hosts, but not for routers (or routing switches).  

Search the forum, or wait for Anusha to post a fix.  I found a fix a month or two ago when I had the same problem. The workaround is to update the associated script include to stop dropping the loopback interface type.

You might need to take further steps to keep addresses in the 127.0.0.0 network from going into the CMDB if that bothers you.

Regards,

Greg Hubbard

PS -- see this post for the fix that I used: link