[Home](./index.md) > [bitburner](./bitburner.md) > [NS](./bitburner.ns.md) > [scan](./bitburner.ns.scan.md) ## NS.scan() method Get the list of hostnames or IP addresses connected to a server. **Signature:** ```typescript scan(host?: string | null, returnOpts?: HostReturnOptions): string[]; ``` ## Parameters

Parameter	Type	Description
host	string \| null	_(Optional)_ Optional. Hostname/IP of the server to scan, default to current server.
returnOpts	[HostReturnOptions](./bitburner.hostreturnoptions.md)	_(Optional)_ Optional. Controls whether the function returns IPs.

**Returns:** string\[\] Returns an array of hostnames. ## Remarks RAM cost: 0.2 GB Returns an array containing the hostnames or IP addresses of all servers that are one node way from the specified target server. The hostnames/IPs in the returned array are strings. Returns hostnames by default. The server network is a tree graph with the home server at the root. The parent node is always the first item of the returned array. For example, let's say the network looks like this: ``` home --n00dles --joesguns ----CSEC ------omega-net ``` ns.scan("home"): \["n00dles", "joesguns"\]: "home" is the root, so it does not have a parent node. ns.scan("n00dles"): \["home"\]: "home" is the parent node of "n00dles". ns.scan("joesguns"): \["home", "CSEC"\]: "home" is the parent node of "joesguns". ns.scan("CSEC"): \["joesguns", "omega-net"\]: "joesguns" is the parent node of "CSEC". ns.scan("omega-net"): \["CSEC"\]: "CSEC" is the parent node of "omega-net". If you run the "scan-analyze" command at home, it won't show all servers due to its limited maximum depth. You can use this function with BFS (Breadth-first search) or DFS (Depth-first search) to traverse the network and discover all servers. ## Example ```js // All servers that are one hop from the current server. ns.tprint("Neighbors of current server."); let neighbor = ns.scan(); for (let i = 0; i < neighbor.length; i++) { ns.tprint(neighbor[i]); } // All servers that are one hop from the current server, but by IP address. ns.tprint("IPs of current server's neighbors."); let neighbor = ns.scan(null, { returnByIP: true }); for (let i = 0; i < neighbor.length; i++) { ns.tprint(neighbor[i]); } // All neighbors of n00dles. const target = "n00dles"; neighbor = ns.scan(target); ns.tprintf("Neighbors of %s.", target); for (let i = 0; i < neighbor.length; i++) { ns.tprint(neighbor[i]); } ```