IP address flip-flopping

[shank1]

Hello,

When some devices have multiple IP address, each time the device is discovered, IP address is changing.

I see that by default the property 'glide.discovery.enforce_ip_sync' is TRUE.

I dont understand why SerivceNow has made it TRUE as default as this leads to confusion as IP keeps flip flopping.

Note- I am thinking because 'glide.discovery.enforce_ip_sync' is set to true, this is happening. 

Please let me know know to avoid this flip flop.

Regards

Shanks

[chuckm · Accepted solution]

If you are using Pattern-based discovery for switches and routers, the issue might be caused by duplicate switch discoveries in the same discovery schedule. The issue is documented in this community article:

Duplicate Discovery of Switch in One Discovery Schedule

One of the issues caused by duplicate switch discovery is the flip flop of IP addresses (#4 below). The duplicate discoveries cause multiple issues:

1. The discovery schedule takes longer to complete.
2. The Discovery Log and ECC Queue fills up with additional messages from the duplicate discoveries.
3. Additional bandwidth is being used across the network.
4. The CI Audit History fills up with additional IP Address changes for each duplicate duplicate discovery.

[MrMuhammad]

Hi Shanks,

You can find the reason in the later section(Discovery Properties) of below KB article. 

https://hi.service-now.com/kb_view.do?sysparm_article=KB0687602

If you do not want to get your IP changed multiple times then you can add comma-separated list of classes to property glide.discovery.exclude_ip_sync_classes. 

Please mark this accepted & helpful if it answered your question.

Thanks & Regards,
Sharjeel

[Ashutosh Munot1]

Hi,

This happens with most of the time with ROuters and switches as they can have multiple IP like Server IP and Management IP, you can also see that this devices have multiple NIC assigned to it. 

This property:glide.discovery.enforce_ip_sync is true means this will assign IP address from one of the NIC IP address and not the one which you see when this discovery runs.

Thanks,
Ashutosh

[chuckm]

shanks,

Some other community articles that might be helpful on the property glide.discovery.enforce_ip_sync:

Issue in CI discovery with Multiple IP address

Whats the use of this Discovery property "glide.discovery.enforce_ip_sync"

Server Discovery - IP field being wiped out or constantly changing