Eu tenho tido um problema estranho em que posso ping apenas PCs específicos na minha LAN, mas não em outros, mas posso me conectar sem esforço à Internet.
o resultado do ping para endereços locais é:
$ ping 192.168.1.10
PING 192.168.1.10 (192.168.1.10) 56(84) bytes of data.
From 192.168.1.30 icmp_seq=10 Destination Host Unreachable
From 192.168.1.30 icmp_seq=11 Destination Host Unreachable
From 192.168.1.30 icmp_seq=12 Destination Host Unreachable
^C
--- 192.168.1.10 ping statistics ---
13 packets transmitted, 0 received, +3 errors, 100% packet loss, time 12086ms
pipe 3
Meu resultado ifconfig é:
eth0 Link encap:Ethernet HWaddr 20:cf:30:75:4c:c1
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:748 errors:0 dropped:0 overruns:0 frame:0
TX packets:628 errors:0 dropped:0 overruns:0 carrier:2
collisions:0 txqueuelen:1000
RX bytes:486220 (486.2 KB) TX bytes:134384 (134.3 KB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:2695 errors:0 dropped:0 overruns:0 frame:0
TX packets:2695 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:258025 (258.0 KB) TX bytes:258025 (258.0 KB)
wlan0 Link encap:Ethernet HWaddr 48:5d:60:5a:53:9c
inet addr:192.168.1.30 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::4a5d:60ff:fe5a:539c/64 Scope:Link
inet6 addr: 2002:4f12:8714:e472:4a5d:60ff:fe5a:539c/64 Scope:Global
inet6 addr: 2002:4f12:8714:e472:5108:36ff:308b:8c09/64 Scope:Global
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:10780 errors:0 dropped:0 overruns:0 frame:0
TX packets:9290 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:5321624 (5.3 MB) TX bytes:1502007 (1.5 MB)
e finalmente minha nmap scan é:
$ nmap -sn 192.168.1.0/24
Starting Nmap 6.40 ( http://nmap.org ) at 2014-04-29 20:26 CEST
Nmap scan report for 192.168.1.1
Host is up (0.0085s latency).
Nmap scan report for 192.168.1.30
Host is up (0.00016s latency).
Nmap scan report for 192.168.1.100
Host is up (0.073s latency).
Nmap done: 256 IP addresses (3 hosts up) scanned in 16.07 seconds
Eu uso isso rotineiramente para compartilhar arquivos no meu NAS local, o que não é visível agora e para bancos de dados XBMC e sei que pings para outros clientes sem fio funcionam.
Meu resultado arp-scan é:
sudo arp-scan --interface=wlan0 192.168.1.0/24
Interface: wlan0, datalink type: EN10MB (Ethernet)
Starting arp-scan 1.8.1 with 256 hosts (http://www.nta-monitor.com/tools/arp-scan/)
192.168.1.1 44:94:fc:ea:f6:5e (Unknown)
192.168.1.100 cc:3a:61:e7:e4:91 (Unknown)
2 packets received by filter, 0 packets dropped by kernel
Ending arp-scan 1.8.1: 256 hosts scanned in 1.331 seconds (192.34 hosts/sec). 2 responded