He escaneado con nmap la red 192.168.1.0/24 y yo tengo solo dos redes creadas 192.168.0.0/24 y 192.168.20.0/24.

Que sorpresa una red fantasma  

Esta red no tengo ni idea, no se de donde salen estos hosts

root@Acer:/home/antonio# nmap 192.168.1.1/24

Starting Nmap 6.00 ( http://nmap.org ) at 2015-04-08 17:14 CEST
Nmap scan report for 192.168.1.1
Host is up (0.0049s latency).
Not shown: 997 closed ports
PORT    STATE    SERVICE
22/tcp  filtered ssh
23/tcp  filtered telnet
179/tcp open     bgp

Nmap scan report for 192.168.1.9
Host is up (0.0062s latency).
Not shown: 999 filtered ports
PORT    STATE  SERVICE
179/tcp closed bgp

Nmap scan report for 192.168.1.10
Host is up (0.0051s latency).
All 1000 scanned ports on 192.168.1.10 are closed

Nmap scan report for 192.168.1.19
Host is up (0.0027s latency).
Not shown: 993 closed ports
PORT     STATE    SERVICE
21/tcp   open     ftp
22/tcp   open     ssh
23/tcp   filtered telnet
37/tcp   open     time
111/tcp  open     rpcbind
2126/tcp open     pktcable-cops
3918/tcp open     pktcablemmcops

Nmap scan report for 192.168.1.117
Host is up (0.0057s latency).
Not shown: 993 closed ports
PORT      STATE SERVICE
21/tcp    open  ftp
22/tcp    open  ssh
80/tcp    open  http
199/tcp   open  smux
443/tcp   open  https
7741/tcp  open  scriptview
10000/tcp open  snet-sensor-mgmt

Nmap scan report for 192.168.1.234
Host is up (0.0065s latency).
Not shown: 985 closed ports
PORT      STATE SERVICE
21/tcp    open  ftp
80/tcp    open  http
135/tcp   open  msrpc
443/tcp   open  https
554/tcp   open  rtsp
1311/tcp  open  rxmon
2869/tcp  open  icslap
3389/tcp  open  ms-wbt-server
10243/tcp open  unknown
49152/tcp open  unknown
49153/tcp open  unknown
49154/tcp open  unknown
49155/tcp open  unknown
49156/tcp open  unknown
49157/tcp open  unknown

Nmap scan report for 192.168.1.236
Host is up (0.0044s latency).
Not shown: 993 closed ports
PORT      STATE SERVICE
21/tcp    open  ftp
22/tcp    open  ssh
80/tcp    open  http
111/tcp   open  rpcbind
199/tcp   open  smux
7741/tcp  open  scriptview
10000/tcp open  snet-sensor-mgmt

Nmap scan report for 192.168.1.237
Host is up (0.0057s latency).
Not shown: 994 closed ports
PORT     STATE SERVICE
135/tcp  open  msrpc
445/tcp  open  microsoft-ds
1025/tcp open  NFS-or-IIS
1028/tcp open  unknown
2099/tcp open  h2250-annex-g
3389/tcp open  ms-wbt-server