If you are searching Graylog logs that are not properly indexed (ip address is not in a field) you may need to perform a text search for an IP Address or IP Addresses.
IP Address Queries
The following queries are examples of how to query Graylog for one or more IP addresses (not using a field)
Query a single IP Address:
The backslashes are optional
10\.2\.1\.15
10.2.1.15
Query with a wildcard in one of the octet positions of the IP Address:
The backslashes are optional
10\.2\.1\.*
10.2.1.*