diff --git a/docs/refguide.xml b/docs/refguide.xml index 10932d16c..7d7523b9b 100644 --- a/docs/refguide.xml +++ b/docs/refguide.xml @@ -94,40 +94,31 @@ A representative Nmap scan example of -# nmap -A -T4 scanme.nmap.org playground +# nmap -A -T4 scanme.nmap.org Starting Nmap ( http://nmap.org ) Interesting ports on scanme.nmap.org (64.13.134.52): -(The 1663 ports scanned but not shown below are in state: filtered) +Not shown: 994 filtered ports PORT STATE SERVICE VERSION -22/tcp open ssh OpenSSH 3.9p1 (protocol 1.99) -53/tcp open domain +22/tcp open ssh OpenSSH 4.3 (protocol 2.0) +25/tcp closed smtp +53/tcp open domain ISC BIND 9.3.4 70/tcp closed gopher -80/tcp open http Apache httpd 2.0.52 ((Fedora)) +80/tcp open http Apache httpd 2.2.2 ((Fedora)) +|_ HTML title: Go ahead and ScanMe! 113/tcp closed auth Device type: general purpose -Running: Linux 2.4.X|2.5.X|2.6.X -OS details: Linux 2.4.7 - 2.6.11, Linux 2.6.0 - 2.6.11 +Running: Linux 2.6.X +OS details: Linux 2.6.20-1 (Fedora Core 5) -Interesting ports on playground.nmap.org (192.168.0.40): -(The 1659 ports scanned but not shown below are in state: closed) -PORT STATE SERVICE VERSION -135/tcp open msrpc Microsoft Windows RPC -139/tcp open netbios-ssn -389/tcp open ldap? -445/tcp open microsoft-ds Microsoft Windows XP microsoft-ds -1002/tcp open windows-icfw? -1025/tcp open msrpc Microsoft Windows RPC -1720/tcp open H.323/Q.931 CompTek AquaGateKeeper -5800/tcp open vnc-http RealVNC 4.0 (Resolution 400x250; VNC port: 5900) -5900/tcp open vnc VNC (protocol 3.8) -MAC Address: 00:A0:CC:63:85:4B (Lite-on Communications) -Device type: general purpose -Running: Microsoft Windows NT/2K/XP -OS details: Microsoft Windows XP Pro RC1+ through final release -Service Info: OSs: Windows, Windows XP +TRACEROUTE (using port 80/tcp) +HOP RTT ADDRESS +[Cut first 7 hops for brevity] +8 10.59 so-4-2-0.mpr3.pao1.us.above.net (64.125.28.142) +9 11.00 metro0.sv.svcolo.com (208.185.168.173) +10 9.93 scanme.nmap.org (64.13.134.52) -Nmap finished: 2 IP addresses (2 hosts up) scanned in 88.392 seconds +Nmap done: 1 IP address (1 host up) scanned in 17.00 seconds @@ -2160,7 +2151,7 @@ script knows about its special argument. performance. A default scan (nmap hostname) of a host on my local network takes a fifth of a second. That is barely enough time to -blink, but adds up when you are scanning tens or hundreds of thousands +blink, but adds up when you are scanning hundreds or thousands of hosts. Moreover, certain scan options such as UDP scanning and version detection can increase scan times substantially. So can certain firewall configurations, particularly response rate limiting. @@ -2170,18 +2161,20 @@ runs. Expert users carefully craft Nmap commands to obtain only the information they care about while meeting their time constraints. - Techniques for improving scan times include omitting - non-critical tests, and upgrading to the latest version of Nmap - (performance enhancements are made frequently). Optimizing timing - parameters can also make a substantial difference. Those options - are listed below. +Techniques for improving scan times include omitting +non-critical tests, and upgrading to the latest version of Nmap +(performance enhancements are made frequently). Optimizing timing +parameters can also make a substantial difference. Those options are +listed below. Some options accept a time parameter. This -is specified in milliseconds by default, though you can append ‘s’, ‘m’, -or ‘h’ to the value to specify seconds, minutes, or hours. So the +is specified in milliseconds by default, though you can append +‘s’, ‘m’, or ‘h’ to the value to +specify seconds, minutes, or hours. So the arguments 900000, 900s, and 15m all do the same thing. + @@ -2285,11 +2278,12 @@ enough by itself. Nmap maintains a running timeout value for determining how long it will wait for a probe response before giving up or retransmitting the probe. This is -calculated based on the response times of previous probes. If -the network latency shows itself to be significant and variable, this -timeout can grow to several seconds. It also starts at a conservative -(high) level and may stay that way for a while when Nmap scans -unresponsive hosts. +calculated based on the response times of previous probes. +The exact formula is given in . +If the network latency shows itself to be significant and variable, +this timeout can grow to several seconds. It also starts at a +conservative (high) level and may stay that way for a while when Nmap +scans unresponsive hosts. Specifying a lower and @@ -2344,7 +2338,8 @@ port. While this benefits accuracy, it also lengthen scan times. When performance is critical, scans may be sped up by limiting the number of retransmissions allowed. You can even specify to prevent any retransmissions, -though that is rarely recommended. +though that is only recommended for situations such as informal +surveys where occasional missed ports and hosts are acceptable. The default (with no template) is to allow @@ -2377,11 +2372,10 @@ slowest few percent of the scanned hosts can eat up a majority of the scan time. Sometimes it is best to cut your losses and skip those hosts initially. Specify with the maximum amount of time you -are willing to wait. I -often specify 30m to ensure that Nmap doesn't waste +are willing to wait. For example, +specify 30m to ensure that Nmap doesn't waste more than half an hour on a single host. Note that Nmap may be -scanning other hosts at the same time during that half an hour as -well, so it isn't a complete loss. A host that times out is skipped. +scanning other hosts at the same time during that half an hour, so it isn't a complete loss. A host that times out is skipped. No port table, OS detection, or version detection results are printed for that host. @@ -2400,7 +2394,7 @@ for that host. This option causes Nmap to wait at least the given amount of time between each probe it sends to a given host. This is -particularly useful in the case of rate limiting. Solaris machines +particularly useful in the case of rate limiting.rate limiting Solaris machines (among many others) will usually respond to UDP scan probe packets with only one ICMP message per second. Any more than that sent by Nmap will be wasteful. A of @@ -2412,13 +2406,18 @@ works best. When Nmap adjusts the scan delay upward to cope with rate limiting, the scan slows down dramatically. The option specifies the largest delay -that Nmap will allow. Setting this value too low can lead to wasteful +that Nmap will allow. A low +can speed up Nmap, but it is risky. Setting this value too low can lead to wasteful packet retransmissions and possible missed ports when the target implements strict rate limiting. Another use of is to evade threshold based intrusion detection and prevention systems -(IDS/IPS).intrusion detection systemsevading +(IDS/IPS).intrusion detection +systemsevading This +technique is used in +to defeat the default port scan detector in Snort IDS. Most other +intrusion detection systems can be defeated in the same way. @@ -2426,53 +2425,69 @@ threshold based intrusion detection and prevention systems - - (Specify a minimum scanning rate) + ; + (Directly control the scanning rate) + Nmap's dynamic timing does a good job of finding an appropriate speed at which to scan. Sometimes, however, you may happen to know an appropriate scanning rate for a network, or you may have to guarantee -that a scan will be finished by a certain time. When the +that a scan will be finished by a certain time. Or perhaps you must keep +Nmap from scanning too quickly. The and + options are designed for these +situations. + +When the option is given Nmap will do its best to -send packets as fast or faster than the given rate. The argument is a +send packets as fast as or faster than the given rate. The argument is a positive real number representing a packet rate in packets per second. For example, specifying means that Nmap will try to keep the sending rate at or above 300 packets per second. Specifying a minimum rate does not keep Nmap from going faster if conditions warrant. +Likewise, limits a scan's sending rate to a +given maximum. Use , for example, to +limit sending to 100 packets per second on a fast network. Use + for a slow scan of one packet every ten +seconds. Use and +together to keep the rate inside a certain range. + +These two options are global, affecting an entire scan, not +individual hosts. They only affect port scans and host discovery scans. +Other features like OS detection implement their own timing. + There are two conditions when the actual scanning rate may fall -below the specified minimum. The first is if the minimum is faster than +below the requested minimum. The first is if the minimum is faster than the fastest rate at which Nmap can send, which is dependent on hardware. -In this case Nmap will send packets as fast as possible, but be aware -that such high rates are likely to cause a loss of accuracy. The second -case is when Nmap has nothing to send, for example at the end of a scan -when the last probes have been sent and Nmap is waiting for them to time -out or be responded to. It's normal to see the scanning rate drop at the -end of a scan or in between groups of hosts. +In this case Nmap will simply send packets as fast as possible, but be +aware that such high rates are likely to cause a loss of accuracy. The +second case is when Nmap has nothing to send, for example at the end of +a scan when the last probes have been sent and Nmap is waiting for them +to time out or be responded to. It's normal to see the scanning rate +drop at the end of a scan or in between hostgroups. The sending rate may +temporarily exceed the maximum to make up for unpredictable delays, but +on average the rate will stay at or below the maximum. Specifying a minimum rate should be done with care. Scanning faster than a network can support may lead to a loss of accuracy. In some cases, using a faster rate can make a scan take longer than it would with a slower rate. This is -because Nmap's adaptive -retransmissionadaptive retransmissionretransmissionretransmission -will detect the network congestion caused by an excessive scanning rate +because Nmap's +adaptive +retransmissionadaptive retransmissionretransmissionretransmission + +adaptive retransmission +algorithms will detect the network congestion caused by an excessive scanning rate and increase the number of retransmissions in order to improve accuracy. So even though packets are sent at a higher rate, more packets are sent overall. Cap the number of retransmissions with the - -option if you need to set an upper limit on total scan + option if you need to set an upper limit on total scan time. -The option is global, affecting an -entire scan, not individual hosts. It only affects port and host -discovery scans. Other features like OS detection implement their own -timing. - @@ -2484,23 +2499,6 @@ timing. -Complementary to is -, which limits a scan's sending rate to a -given maximum. Use , for example, to -limit sending to 100 packets per second on a fast network. Use - for a slow scan of one packet every ten -seconds. - -, like , is -a global option affecting an entire scan. It affects only port and host -discovery scans. - -The sending rate may temporarily exceed the maximum to make up for -unpredictable delays, but on average the rate will stay at or below the -maximum. Nmap may go slower than the maximum rate if conditions require -it. To keep the sending rate within a specified range, use - and -together. diff --git a/docs/scripting.xml b/docs/scripting.xml index fd299b080..d39aacd04 100644 --- a/docs/scripting.xml +++ b/docs/scripting.xml @@ -177,7 +177,7 @@ PORT STATE SERVICE Host script results: |_ RIPE Query: IP belongs to: Internet Assigned Numbers Authority -Nmap finished: 1 IP address (1 host up) scanned in 0.907 seconds +Nmap done: 1 IP address (1 host up) scanned in 0.91 seconds @@ -3482,7 +3482,7 @@ local localip, localport = client_service:get_info() --- Checks if an FTP server allows anonymous logins. -- @output --- |_ Anonymous FTP: Anonymous login allowed" +-- |_ Anonymous FTP: Anonymous login allowed The standard NSE fields are used to gather other information about a script such as the author or its categories: @@ -3754,7 +3754,7 @@ PORT STATE SERVICE VERSION 80/tcp open [Name] [Product] [Version] ([ExtraInfo]) Service Info: Host: [HostName]; OS: [OSType]; Device: [DeviceType] -Nmap finished: 1 IP address (1 host up) scanned in 9.317 seconds +Nmap done: 1 IP address (1 host up) scanned in 9.32 seconds