Telnet not working (Port25)

[ahuxham]

Hi All,

 

Quick question. I cannot telnet from a certain server. It has been recently rebuilt Windows 2003 Standard + SP2.

 

Trying telnet server 25 in CMD and it says "Could not open connection to host". However running this from my laptop, and I get in straight away, same with all the other servers. Windows firewall is not enable, there are no port blocks or anything along those lines.

 

Just find it bemusing it isn't working. It has software on it, thats meant to send quite a bit of mail traffic through. Which would be SMTP:25. (Same installing the program on my machine, it works correctly)

 

Any reason Port 25 would be blocked? Or anyway to find if something is using that port.

 

Many Thanks

[OutToLunch]

Do you mean you cannot telnet from the server to another server, or you cannot telnet to the newly rebuilt server on its SMTP port? Got a bit lost in your first couple of lines...

 

If it's not being able to telnet from it, does your network firewall have restrictions by IP/MAC address as to what protocols may be used? Is it a DNS issue - tried telnet ip 25 ?

[Netman]

Is the SMTP service installed and running on the server?

[ahuxham]

Not a DNS setting thats for sure, same error appears with an IP address

 

Server to Server (telnet works) APART!! From this one server, which has recently been rebuilt.

 

The only IP/MAC Firewall filtering in-place is inbound gateway, on the staffs internet gateway (BIND-IP to MAC) Vigor3300, but thats outside, not inside

[ahuxham]

Is the SMTP service installed and running on the server?

 

On the server the software is running from, or the server I'm trying to telnet too.

 

 

Wsusserver (Has Ilient Sysaid installed) Its supposed to send email notification on tickets and servers that are down via SchoolMailServer. Settings are all correct however, it wont send the SMTP request to the SchoolMailServer.

 

However, if I install Sysaid on my laptop, and configure it exactly as above, it routes the notifications (or rather sends them) via the Mail Server.

[Michael]

Does the problem happen over wireless or wired? If wireless it might be your AP blocking Telnet.

[ahuxham]

Does the problem happen over wireless or wired? If wireless it might be your AP blocking Telnet.

 

Wired. The telnet command is only really there as the end solution, more along the lines of trying to see if the server is routing smtp traffic properly which its not.

 

Another point, working from my Laptop, I'm the only one without Mcafee AV on, while the servers and all other workstations have it. Having tripple checked other machines, they cannot telnet, where I can.

 

I cannot see anything in the server policies nor workstation policies covering telnet, or any SMTP traffic scanning anywhere.

[Michael]

You could experiment and remove McAfee off one workstation temporarily and see if it works. If it's just the AV then that would be strange, but I know McAfee also do a security suite, which would include spyware and firewall too.

[ahuxham]

You could experiment and remove McAfee off one workstation temporarily and see if it works. If it's just the AV then that would be strange, but I know McAfee also do a security suite, which would include spyware and firewall too.

 

Will do, but at present we don't have Firewall/Spyware packages installed, just pure Virus Scan.

[OutToLunch]

I have McAfee Enterprise V8 AV installed here - it still has some basic firewall/port blocking functionality. Look in console for the the configuration for "Access Protection" - under Access Protection Properties there is a rule "Stop mass mailing worms from sending email" which blanket blocks outbound port 25 apart from programs in the exclusions list, which contains

 

"amgrsrvc.exe,tomcat.exe,outlook.exe,msimn.exe,agent.exe,eudora.exe,nlnotes.exe,mozilla.exe,netscp.exe,opera.exe,winpm-32.exe,pine.exe,poco.exe,thebat.exe,thunderbird.exe,ntaskldr.exe,inetinfo.exe,nsmtp.exe,nrouter.exe,tomcat5.exe,tomcat5w.exe,ebs.exe,FireSvc.exe,modulewrapper.exe,MSKSrvr.exe,MSKDetct.exe,mapisp32.exe" on my system but strangely no telnet. Whack telnet.exe or whatever executable is supposed to be sending mail in and you're sorted. Probably.

[ahuxham]

Thanks for that OutToLunch, solved the problem perfectly.