From a different machine: telnet

Like: telnet somehost 22 will tell you if 22 is "open" YMMV... :) ET Marco Savo writes: > Thanks, but currently I have an embedded linux board (based on openwrt) that > use busybox, and there isn't netstat, neither nmap or lsof command. I guess > i can read /proc/net/tcp or udp, but iptables doesn't show a list of used > ports? > > On Fri, Nov 6, 2009 at 1:49 PM, Lisa Kachold wrote: > >> >> >> On Fri, Nov 6, 2009 at 5:30 AM, Craig White wrote: >> >>> On Fri, 2009-11-06 at 13:13 +0000, Marco Savo wrote: >>> > Hello, >>> > configuring iptables rules, >>> > how I can find out if one port number I want to use is already in >>> > use? >>> > example: >>> > >>> > $IPTABLES -t nat -I zone_wan_prerouting 1 -j ACCEPT --protocol udp >>> > --dport ${UDP_PORT} --destination localhost >>> > $IPTABLES -t nat -I zone_wan_prerouting 1 -j ACCEPT --protocol tcp >>> > --dport ${TCP_PORT} --destination localhost >>> > $IPTABLES -t nat -I zone_wan_prerouting 1 -j ACCEPT --protocol tcp >>> > --dport ${TCP_HOST_PORT} --destination localhost >>> > >>> > How I can check if these ports (UDP_PORT TCP_PORT TCP_HOST_PORT) are >>> > in use from another application? >>> ---- >>> you can use netstat - for example, I might check for port 10000... >>> # netstat -an|grep 10000 >>> tcp 0 0 0.0.0.0:10000 0.0.0.0:* LISTEN >>> udp 0 0 0.0.0.0:10000 0.0.0.0:* >>> >>> Craig >>> >>> >>> You can also use nmap >> >> # nmap localhost >> >> or >> >> # netstat -anpt >> >> to see what is listening on what (depending on your distro - check syntax >> >> >> -- >> Skype: (623)239-3392 >> AT&T: (503)754-4452 >> www.obnosis.com >> >> >> >> >> >> >> >> >> >> >> >> >> --------------------------------------------------- >> PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us >> To subscribe, unsubscribe, or to change your mail settings: >> http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss >> > > > > -- > 'The Magic Is In the Movement' > > Marco Savo > SW Engineer > > 882 East Glenn St. > Tucson, AZ 85719 > +1 (520) 248-5681 --------------------------------------------------- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss