|
What are LISTENING ports?
Java Security,Windows code security, Windows Server 2003 Security,Internet Explorer 7 Security and Internet Firewalls questions and answers
(Continued from previous question...)
What are LISTENING ports?
Suppose you did ``netstat -a'' on your machine and ports 1025 and 1030 showed up as LISTENing. What do they do?
Right, let's take a look in the assigned port numbers list.
blackjack 1025/tcp network blackjack
iad1 1030/tcp BBN IAD
Wait, what's happening? Has my workstation stolen my VISA number and decided to go play blackjack with some rogue server on the internet? And what's that software that BBN has installed?
This is NOT where you start panicking and send mail to the firewalls list. In fact, this question has been asked maybe a dozen times during the past six months, and every time it's been answered. Not that THAT keeps people from asking the same question again.
If you are asking this question, you are most likely using a windows box. The ports you are seeing are (most likely) two listening ports that the RPC subsystem opens when it starts up.
This is an example of where dynamicly assigned ports may be used by server processes. Applications using RPC will later on connect to port 135 (the netbios ``portmapper'') to query where to find some RPC service, and get an answer back saying that that particular service may be contacted on port 1025.
Now, how do we know this, since there's no ``list'' describing these ports? Simple: There's no substitute for experience. And using the mailing list search engines also helps a hell of a lot.
(Continued on next question...)
Other Interview Questions
- Is Java secure?
- What are the risks?
- How common are security breaches?
- Who is at risk?
- How can I protect myself?
- What about products that claim to detect malicious applets?
- What about products that claim to block Java applets at a firewall?
- Which is more secure: Java or ActiveX?
- Which version of my browser should I use?
- What about ``hostile applets?''
- I run a Web server. Am I at risk?
- What about JavaScript?
- What’s the difference between code-based security and role-based security? Which one is better?
- How can you work with permissions from your .NET application?
- How can C# app request minimum permissions?
- What’s a code group?
- What’s the difference between authentication and authorization?
- What are the authentication modes in ASP.NET?
- Are the actual permissions for the application defined at run-time or compile-time?
- # What’s the difference between local, global and universal groups?
- # I am trying to create a new universal user group. Why can’t I?
- # What is LSDOU?
- # Why doesn’t LSDOU work under Windows NT?
- # Where are group policies stored?
- # What is GPT and GPC?
- # Where is GPT stored?
- # You change the group policies, and now the computer and user settings are in conflict. Which one has the highest priority?
- # You want to set up remote installation procedure, but do not want the user to gain access over it. What do you do? gponame–>
- # What’s contained in administrative template conf.adm?
- # How can you restrict running certain applications on a machine?
- # You need to automatically install an app, but MSI file is not available. What do you do?
- # What’s the difference between Software Installer and Windows Installer?
- # What can be restricted on Windows Server 2003 that wasn’t there in previous products?
- # How frequently is the client policy refreshed?
- # Where is secedit?
- # You want to create a new group policy but do not wish to inherit.
- # What is "tattooing" the Registry?
- # How do you fight tattooing in NT/2000 installations?
- # How do you fight tattooing in 2003 installations?
- # What does IntelliMirror do?
- # What’s the major difference between FAT and NTFS on a local machine?
- # How do FAT and NTFS differ in approach to user shares?
- # Explan the List Folder Contents permission on the folder in NTFS.
- # I have a file to which the user has access, but he has no folder permission to read it. Can he access it?
- # For a user in several groups, are Allow permissions restrictive or permissive?
- # For a user in several groups, are Deny permissions restrictive or permissive?
- # What hidden shares exist on Windows Server 2003 installation?
- # What’s the difference between standalone and fault-tolerant DFS (Distributed File System) installations?
- # We’re using the DFS fault-tolerant installation, but cannot access it from a Win98 box.
- # Where exactly do fault-tolerant DFS shares store information in Active Directory?
- # Can you use Start->Search with DFS shares?
- # What problems can you have with DFS installed?
- # I run Microsoft Cluster Server and cannot install fault-tolerant DFS.
- # Is Kerberos encryption symmetric or asymmetric?
- # How does Windows 2003 Server try to prevent a middle-man attack on encrypted line?
- # What hashing algorithms are used in Windows 2003 Server?
- # What third-party certificate exchange protocols are used by Windows 2003 Server?
- # What’s the number of permitted unsuccessful logons on Administrator account?
- # If hashing is one-way function and Windows Server uses hashing for storing passwords, how is it possible to attack the password lists, specifically the ones using NTLMv1?
- # What’s the difference between guest accounts in Server 2003 and other editions?
- # How many passwords by default are remembered when you check "Enforce Password History Remembered"?
- #1: Default protection from potentially dangerous Active X controls
- #2: Per-zone control of Active X opt-in
- #3: Site and zone locking for Active X controls
- #4: Protection against phishing
- #5: Cross-domain security
- #6: Locked down security zones
- #7: Better SSL/TLS notification and digital certificate info
- #8: Privacy protection features
- #9: Address bars
- #10: International character alert
- What is a network firewall?
- Why would I want a firewall?
- What can a firewall protect against?
- What can't a firewall protect against?
- What about viruses and other malware?
- Will IPSEC make firewalls obsolete?
- Where can I get more information on firewalls on the Internet?
- What are some of the basic design decisions in a firewall?
- What are the basic types of firewalls?
- Network layer firewalls
- Application layer firewalls
- What are proxy servers and how do they work?
- What are some cheap packet screening tools?
- What are some reasonable filtering rules for a kernel-based packet screen?
- What are some reasonable filtering rules for a Cisco?
- What are the critical resources in a firewall?
- What is a DMZ, and why do I want one?
- How might I increase the security and scalability of my DMZ?
- What is a `single point of failure', and how do I avoid having one?
- How can I block all of the bad stuff?
- How can I restrict web access so users can't view sites unrelated to work?
- What is source routed traffic and why is it a threat?
- What are ICMP redirects and redirect bombs?
- What about denial of service?
- What are some common attacks, and how can I protect my system against them?
- Do I really want to allow everything that my users ask for?
- How do I make Web/HTTP work through my firewall?
- How do I make SSL work through the firewall?
- How do I make DNS work with a firewall?
- How do I make FTP work through my firewall?
- How do I make Telnet work through my firewall?
- How do I make Finger and whois work through my firewall?
- How do I make gopher, archie, and other services work through my firewall?
- What are the issues about X11 through a firewall?
- How do I make RealAudio work through my firewall?
- How do I make my web server act as a front-end for a database that lives on my private network?
- But my database has an integrated web server, and I want to use that. Can't I just poke a hole in the firewall and tunnel that port?
- How Do I Make IP Multicast Work With My Firewall?
- What is a port?
- How do I know which application uses what port?
- What are LISTENING ports?
- How do I determine what service the port is for?
- What ports are safe to pass through a firewall?
- The behavior of FTP
- What software uses what FTP mode?
- Is my firewall trying to connect outside?
- The anatomy of a TCP connection
- Glossary of Firewall-Related Terms
| 