Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

I've just done a simple nmap scan of my network with nmap: nmap -sP 192.168.1.1-255

networkserver@networkServer:~$ sudo nmap -sP 192.168.1.1-255

Starting Nmap 5.00 ( http://nmap.org ) at 2010-08-26 17:46 NZST
Host RTA1320.home (192.168.1.1) is up (0.00060s latency).
MAC Address: 00:26:B6:C9:E7:48 (Unknown)
Host 192.168.1.2 is up (0.00057s latency).
MAC Address: 00:23:69:16:85:D7 (Cisco-Linksys)
Host 192.168.1.3 is up (0.00015s latency).
MAC Address: 02:27:19:B4:61:DB (Unknown)
Host networkServer (192.168.1.50) is up.
Host 192.168.1.104 is up (0.0012s latency).
MAC Address: 00:1A:4D:9C:70:0E (Giga-byte Technology Co.)
Host 192.168.1.109 is up (0.0076s latency).
MAC Address: 78:E4:00:8E:FE:63 (Unknown)
Nmap done: 255 IP addresses (6 hosts up) scanned in 28.74 seconds

That seemed to take a rather long time, so I check with a friend on his network and it only took 2.74 secconds!

My network layout is:

                             /---WifiRouter----#laptop>
Modem----server---switch---->
                             \---#devbox

I figure something is wrong with the routing settings on my network but I'm not sure how to check it? Any ideas?

share|improve this question
    
Which machine are you scanning from? What OS/Version etc? –  Grizly Aug 26 '10 at 6:23
    
I am scanning from "server", OS=Ubuntu 10.4 –  glisignoli Aug 26 '10 at 6:31
    
Ok I tried this: nmap -sP 192.168.1.1 (modem) ... Nmap done: 1 IP address (1 host up) scanned in 0.72 seconds nmap -sP 192.168.1.104 (LAPTOP) ... Nmap done: 1 IP address (1 host up) scanned in 13.68 seconds So the problem is the wifi router, I just tried plugging in a device into the router and the same problem happens. So it's not just over wifi connections but also wired ones! ARGH! –  glisignoli Aug 26 '10 at 6:50

2 Answers 2

up vote 0 down vote accepted

The network you checked was the same ? Machines / Os / topology. Also, do you (or he) have/has QOS enabled on your / his switch ?

Also it would be helpful it you give the Ip's of every machine. (to know what is what). Just to mention that it seems that your bottleneck is located on 192.168.1.104 (Giga-byte Technology Co.). What is it ?

share|improve this answer
    
192.168.1.104 was it! –  glisignoli Dec 26 '10 at 8:27

Could you give the output of command (on the server): # route -n ?

share|improve this answer
    
Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 0.0.0.0 192.168.1.1 0.0.0.0 UG 100 0 0 eth0 –  glisignoli Aug 26 '10 at 6:55

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.