What port numbers you should block if you want to block all email traffic?

What port numbers you should block if you want to block all email traffic?

For example, the SANS Institute recommends blocking outbound traffic that uses the following ports: MS RPC – TCP & UDP port 135. NetBIOS/IP – TCP & UDP ports 137-139. SMB/IP – TCP port 445.

How do I block ports on my Cisco firewall?

Blocking the Ports Configuration

1. Go to Configuration > Firewall > Access Rules.
2. Define the source and destination and the action of the access-rule along with the interface that this access rule will be associated.
3. Choose http from the list of available ports, then click OK to revert back to the Add Access Rule window.

How can I tell if my firewall is blocking port 80?

Option 1: Checking Windows Firewall for blocked ports via Windows Firewall Logs

1. Start >> Control Panel >> Administrative Tools >> Windows Firewall with Advanced Settings.
2. From the Actions pane (right-pane) click on Properties.
3. Select the appropriate firewall profile (Domain, Private or Public).

Is it safe to leave port 80 open?

There is nothing insecure about port 80 being open. Security issues only occur when the web server is serving requests over an unencrypted connection, especially if those requests contain sensitive data. Having port 80 be open and send nothing more than an HTTP redirect (301) is perfectly safe.

Should I block port 123?

Port 123: NTP UDP This port is associated with NTP, the network time protocol. Due to ongoing security vulnerabilities, incoming connections are only permitted to connect to approved campus NTP servers. (Outgoing requests from on-campus machines to off-campus NTP servers will not be blocked.)

Can a router block ports?

There are two ways to block ports on a D-Link router. By default, D-Link routers already block unsolicited traffic to all ports, however, if someone on your network is using high-bandwidth applications, like peer-to-peer downloading apps, closing ports completely can often be useful.

Is there an ACL to block one UDP port?

02-17-2016 06:16 AM I am a novice at this, but I need to create an ACL to block a particular UDP port and allow all other traffic. This is on a small private network in a lab. I tried this, but it doesn’t work: All traffic still seemed to get through. Any advice would be appreciated. 02-18-2016 05:03 AM 02-18-2016 05:03 AM

How to create ACL to block http-Cisco community?

06-15-2017 12:00 PM Create an extended Routed Access List (RACL) on Router 2 that reads like this: Apply the ACL to FA0/1 interface on R2 using the ip access-group (ACL Name) in command as the ACL blocking action should always be placed as close as possible to the hosts being blocked.

How to configure commonly used IP ACLs-Cisco?

Refer to Configuring IP Access Lists for more information on different types of ACLs supported in Cisco IOS Software and how to configure and edit ACLs. The command syntax format of a standard ACL is access-list access-list-number {permit|deny} {host|source source-wildcard|any}.

How to tell which ACL rule is blocking traffic?

Well the ASA does have a tool that can easily tell you which ACL rule some traffic hits. Though I guess there is a very small change that you would have so old software that its not supported but I doubt it. This command isnt supported on FWSM however. On ASA you can use the “packet-tracer” command.